This section is for storm chases done in the central / Midwestern United States during the year of 2010. This includes all storm chasing activities (including any major chase "expeditions") during the year of 2010 in the central USA (aka "Tornado Alley"). For 2010, all chases in the central USA will be logged in this section, with many of the chases being possible "spot" chases / major severe weather "setups" chased. Here you should find many pictures of lightning, possible tornadoes, along with many severe thunderstorm elements. Keep in mind that this chase log is scientific evidence and portrays my on-going storm chasing research. It has been placed on this page for easy reference and meteorological interests. Please do not plagiarize or copy this document to other sites for distribution.

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STORM CHASING - CENTRAL UNITED STATES - 2010 CHASE LOGS

Above is a picture of Yazoo City, Mississippi just after a violent tornado (rated EF-4 and nearly TWO miles wide) hit the town on April 24, 2010 just before noon. This was a classic case where a storm chase had to be aborted for the sake of stopping and helping the victims of such a horrific tornado disaster - Not something a storm chaser wants to see and do. Tornadoes and supercells, although a spectacular display of nature's power, can inflict catastrophic damage to lives and property to those caught in its path. The violent cyclic supercell that produced the tornado was a very long track storm that tracked across a path of about 200 miles, crossing at least 2 states. The tornado path itself was nearly a staggering 150 miles in length. At least 10 people were killed by this tornado, three of them children. This drives home the sobering reminder of how storm chasing can involve witnessing the darkest moments in life first hand, so always chase with responsibility and respect for such.

TABLE OF CONTENTS - CLICK TO GO TO PAGE

ABOUT THIS CHASE LOG FOR THE MIDWEST

This is a chase log for any chases during 2010 in the Midwest and Central United States that were conducted as "spot" chases as well as any dedicated chase trip. Each chase section within this area will have its own details and such for that particular chase. This area was set up in the late spring of 2010 and is for any chase that was conducted in the US Plains and Midwest. Equipment use in such chases range from cell phone to HAM radio communications, digital / still cameras, video (SD) and high-definition (HD) camcorders, and data logging / GPS via laptop computer. Storm chasing involved driving in harsh conditions and / or for long periods of time.

All chases and observations are in chronological order and a chase number is assigned to each entry. Please bear in mind that all observations adhere to modern storm analysis standards and do not include all storms that occurred in a given area for a particular chase period.

Any kind of storm such as a thunderstorm, tornado, waterspout, tropical cyclone, and extratropical storm can be chased or observed. I have tried to keep this log of any storms that I have observed as accurate as possible, while using terms and expressions to abide by those used by most meteorologists and storm spotters today.

Storm chasing and observation can be extremely dangerous and may result in serious injury or death. I have received intermediate and advanced training for storm spotting in 1996. I strongly urge anyone who is to try their hand at storm spotting to get training before doing so. You must also have a good understanding of meteorology and storm dynamics. "If you don't know what you're doing, Don't do it!" Contact your local National Weather Service office for information on storm spotting and about training to become a Skywarn storm Spotter.

CHOOSE A VIDEO CLIP BELOW - LINKS TO YOUTUBE

Central US Storm Chase Trip I (April 22-24)
Yazoo City (MS) Just After EF-4 Tornado (April 24)
Central US Storm Chase Trip II / OK Outbreak (May 10-12)
Violent Tornadoes Near Bowdle, SD On May 22, 2010
Bowdle, SD Damage Survey / KS Tornadoes On May 23, 2010
Tornadoes In CO / KS On May 25, 2010
Chase 2010 Music Video (NSCC 2011)

CHASE LOG FOR APRIL 21 TO APRIL 25, 2010

Above is the chase map for the April 21 through 25 chase trip in the Central United States. In the diagram, an overview inset to the lower left shows the chase area (boxed) and the flight path (green) between Fort Lauderdale, Florida and the "base" city of Dallas, Texas. The blue path in the main diagram is the chase track totaling 2350 miles. States involved were AR, KS, LA, MS, OK, and TX. There were three target areas (based on my forecasting) that pretty much agree with the outlook areas from the Storm Predictions Center (SPC). Each red "X" marks any interceptions or observations of severe weather (hail, tornadoes, etc). The first target on April 22 was pretty much spot-on with my forecasting, however, many of the tornadoes (that occurred in the central portions of the area) were missed simply because I abandoned the target and went too far north (thanks to impatience). The other two target areas were on April 23 in Arkansas and finally on April 24, which included the area a devastating tornado struck a town in Mississippi.

CHASE SUMMARY FOR APRIL 21 THROUGH APRIL 25, 2010

This was a 5 day "spot chase" (3 of the days were spent chasing, the other 2 travel days) that began on April 21, 2010 by flying into Dallas, Texas from Fort Lauderdale, Florida (with a stop in Houston). After flying into Dallas, I picked up the rental vehicle, a 2009 Kia Forte, and set up the equipment for storm chasing. With the original target for April 22 to be in the TX Panhandle / W Oklahoma area, I figured a drive to Elk City, Oklahoma would be a good choice. Upon leaving Dallas, I drove up I-35 to Oklahoma city, Oklahoma, then west along I-40 to the town of Elk City for the night.

On April 22, I forecasted for the day in Elk City, and left for the rather close target of near Wheeler, Texas by heading west on I-40, then north a bit out of Sayre via Highway 30 then into Wheeler via Highway 152. This became a decision point while in Wheeler ... Stick with my original target, the one I spend many hours of forecasting to refine, and stay in Wheeler and wait - Or jump on the storms already going by early afternoon farther north towards the Oklahoma Panhandle? Well, I chose the latter - Probably one of the biggest chasing mistakes I ever made: Never abandon your FIRST target.

I headed to Liberal, Kansas up Highway 83, eventually meeting with Verne Carlson, and intercepted the first tornadic supercell along Highway 54. After that storm weakened, we dropped south out of Hooker, OK and onto Highway 94 and 3 to get back to Highway 84 for a storm near Perryton, Texas. After intercepting this storm, we heard of multiple tornadoes around I-40 to the south near Clarendon, Texas - Too far to reach in time, and a mere 20 miles or so from my original target of Wheeler. Lesson learned - Stay true to your first target. A last ditch effort to drop south landed my along highway 70 to near Pampa, then back towards Wheeler, Texas along Highway 152. The tornadic storms were all a multicell complex of storms, so the chase was finished. I headed back east along Highway 152 to I-40, spending the night in Oklahoma City anticipating activity farther east.

On April 23, I left Oklahoma City for the moderate-risk chase in Arkansas (and in terrible chase terrain). This day actually had TWO target areas, one to the north to southeastern Nebraska for a cold core type event, and another area in Arkansas, the latter having the highest tornado possibilities. Verne (and many other chasers) chose the northern target, favoring better chase terrain. I decided to stick with my original target after what happened the day before. I headed east along I-40 until I got through Fort Smith, Arkansas and eventually to near Little Rock.

Storms began developing, and my first storm was encountered west of Little Rock near Perryville along Highways 9 and 10 and into Morrilton. This area is HORRIBLE for chasing as there are trees, winding and hilly roads. After this storm, I headed back to I-40 and through Little Rock and east on Highway 70 where a second severe storm was encountered near Lonoke. Traveling back in Highway 70 to I-40, I passed south of Little Rock and southwest along I-30 to head to new supercells in a better environment near Hope and Texarkana. The supercell was encountered near Prescott along I-30 and followed east and southeast along Highway 371 towards Stamps, Arkansas. The chase was wrapped up by heading back west on Highway 82 and spending the night in Texarkana. Little happened in the northern target area mentioned earlier.

A rude awakening occurred at my motel in Texarkana as I woke to a very severe storm at roughly 4:30 in the morning, where hail bounced into my room as I cracked the door. Unable to sleep much, I woke again at 7:30 AM and checked data. A high risk was in place, and a nice area of dynamics appeared to be in place in the extreme SE corner of Arkansas and into Mississippi. I left Texarkana and headed back east, generally along Highway 82, which winds its way across the state into the relatively better chase areas in SE Arkansas. I crossed over into Mississippi at about 11 AM or so, crossing the mighty river and catching up with Highway 61 to head south towards a developing supercell storm. This storm would be the violent supercell, including the tornado that hit Yazoo City, Mississippi.

I continued south on Highway 61, then east on Highway 12 to Highways 149 and eventually 49, negotiating the dangerous core of the supercell and avoiding driving into the tornado 9but desperately trying to keep up with the fast moving storm). The chase ended in a very sad way in Yazoo City, near Highway 49 and 16, where EF-4 tornado damage was observed. I stopped and helped out there for a few hours. After my "stay" in Yazoo City, I heded south on 49 to I-20, then took that all the way west into Dallas, Texas for the last night. On April 26, I left Dallas and flew back to Fort Lauderdale, Florida.

APRIL 21 TO APRIL 25 CHASE MAIN PARTICIPANTS

CHASER NAMEHOME CITYCALLSIGNCHASE DATESOCCUPATION
CHRIS COLLURASUNRISE, FLKG4PJN4-21 TO 4-25IT CONSULTANT

STORM REPORTS FOR APRIL 22-24, 2010

Above is a diagram with 3 images for the SPC storm reports for the days of April 22 (left), April 23 (middle), and April 24 (right) in 2010. In each of the reports, episodes of severe weather reported are shown by a red dot (tornado), green dot (hail at or over 1 inch), and blue dot (severe wind over 50 Knots). Black squares represent extreme winds (over 65 Knots) and the black triangles are giant hail (2" or larger). All three days had reports of all aspects of severe weather, with the least on April 23. The right image, ofcourse, shows the typical "outbreak" pattern. Note the long track of red dots on the right image, nearly completely crossing Mississippi from NE louisiana to western Alabama (the supercell that also prduced the Yazoo City tornado)!

FORECASTING AND TARGET AREA - APRIL 22

Above is a diagram showing the Storm Prediction center (SPC) forecast products for the areas in concern for April 22, 2010. To the left is the tornado probabilities, with a 10% (hatched) outlook area, pretty much in-sync with my forecast target area. In the middle and right images, are the MCD (mesoscale discussion) 342 and subsequent tornado watch 75 issued for the area, respectively.

FORECASTING AND TARGET AREA - APRIL 23

Above is a diagram showing the Storm Prediction center (SPC) forecast products for the areas in concern for April 23, 2010. To the left is the categorial risks, with a large slight-risk area, and moderate risk in Arkansas and Louisiana. Looking into the tornado probabilities in the middle image, a rather high 15% (hatched) outlook area is given for the moderate-risk, as well as a 10% area for the aformentioned northern target in Nebraska. The image to the right is for the areal (watch) product for tornado watch 80.

FORECASTING AND TARGET AREA - APRIL 24

Above is a diagram showing the Storm Prediction center (SPC) forecast products for the areas in concern for April 24, 2010. The most striking outlooks are in the left and middle images, showing a high-risk outlook and staggering tornado probabilities of 30% (hatched). Even more frightening is the large area the high-risk covers. To thr right, we see one of many tornado watches, issued for that day. The watch box (tornado watch 91) was also PDS (particularly dangerous situation) suggesting strong tornadoes, such as the one that struck Yazoo City, Mississippi.

ENERGY AND HELICITY - APRIL 24

Above is a diagram that shows something that you do not see every day. It is three forecast products, two from the NCAR (National Center for Atmospheric Research / RUC analysis model) and one from SPC. The left one shows the available CAPE (convective available potential energy) associated with the high-risk area outlooked by SPC, where all values approach 3000 Joules / KG. The middle image shows something I have never seen before, a helicity of over 1000 M-squared / s-squared, over a wide area! A helicity of 150 and over is more than enough for supercells. This yeilds and energy-helicity index (EHI) approaching 20 (any value over just 1 is good for supercells). To the right is a "cluster" of tornado watch boxes issued by the SPC, all active at the time.

STORM RADAR IMAGERY - APRIL 24

Here are some of the radar images of the violent supercell storm while it was near and striking the unfortunate town of Yazoo City, Mississippi. To the left, the base reflectivity shows a very wound-up HP supercell storm, with a "debris knob" - Possibly containing material lofted into the air by the violent (EF-4) tornado - On the SW side of the HP supercell storm. To the right, the divergence (velocity couplet) presented by doppler radar shows massive inbound and outbound velocities associated with the storm mesocyclone - Pretty much OVER the town of Yazoo City.

DETAILED LOG ALL CHASES

1). April 22, 3:30 PM - Interception and observation of an extremely severe thunderstorm between Guymon, Oklahoma and Liberal, Kanasas from along Highway 54 (Near Hooker / Tyrone) mainly in Texas County, Oklahoma and Seward County, Kansas. The storm was a classic supercell thunderstorm, and produced at least one weak tornado during its observed life-cycle of a couple of hours. A possible view of the brief tornado was made from a distance of about 5 miles. The storm core was not penetrated, but winds (inflow) of about 35 MPH were experienced, along with frequent lightning. The storm core also had hail at least golfball sized. Conditions causing the storm were a dryline / frontal boundary interaction (triple point), surface heating, a low pressure area, and strong winds (divergence) aloft / wind shear. A 2009 Kia Forte was used to chase the storms. Documentation was still digital photos and HD video. A tornado watch was also in effect for the area until 10 PM CDT.

2). April 22, 6:30 PM - Interception and observation of an extremely severe thunderstorm near Perryton, Texas in Ochiltree County from along Highway 83. The storm was a classic supercell thunderstorm with a possible tornado (not directly observed). The main core of the storm (also with 60 MPH+ winds and frequent lightning) was not penetrated, however, a region of large hail (1") covering the ground was encountered with inflow winds to near 50 MPH roughly 5 miles from the storm core (hail was falling from storm anvil). Conditions causing the storm were a dryline / frontal boundary interaction (triple point), surface heating, a low pressure area, and strong winds (divergence) aloft / wind shear. A 2009 Kia Forte was used to chase the storms. Documentation was still digital photos and HD video. A tornado watch was also in effect for the area until 10 PM CDT.

3). April 23, 4:00 PM - Observation of an very severe thunderstorm near Perryville, Arkansas in Perry County near Highways 9 and 10. The storm was a multicell storm cluster with an embedded and intense HP supercell. The storm was also tornado warned (radar indicated). The of this storm was not penetrated, but the chase path came across hail fig and a hail accumulation on the ground behind the storm near Harris Brake reservoir. The storm core contained winds to about 60 MPH and hail up to 1". The storm was followed to near I-40 and the town of Morrilton (where tornado sirens were activated). Conditions causing the storm were surface heating, a low strong pressure area, and strong winds / cold air aloft. A 2009 Kia Forte was used to chase the storms. Documentation was still digital photos and HD video. A tornado watch was also in effect for the area until 8 PM CDT.

4). April 23, 6:00 PM - Observation and penetration of a strong to severe thunderstorm near Lonoke, Arkansas in Lonoke County along and near Highway 70. The storm was a multicell storm and contained winds near 60 MPH, small hail, torrential rains, and frequent lightning. Conditions causing the storm were surface heating, a low strong pressure area, and strong winds / cold air aloft. A 2009 Kia Forte was used to chase the storms. Documentation was still digital photos. A tornado watch was also in effect for the area until 8 PM CDT.

5). April 23, 9:00 PM - Observation and penetration of a very severe thunderstorm near Prescott, Arkansas in Nevada County along and near Interstate 30 and southward along Highway 371 (eventually to near Stamps). The storm was a supercell storm (possibly tornadic) and contained winds over 70 MPH, large hail to about 1", torrential rains, and frequent lightning with some close hits. The tornado (if any) was not observed once in the rain-free region of the storm. Conditions causing the storm were surface heating, a low strong pressure area, and strong winds / cold air aloft. A 2009 Kia Forte was used to chase the storms. Documentation was still digital photos and HD video. A tornado watch was also in effect for the area until 3 AM CDT the next day.

6). April 24, 4:30 AM - Observation of a very severe thunderstorm at a motel off exit 223 of Interstate 30 in Texarcana, Arkansas in miller County. The storm was an intense multicell storm that pushed through the area, and the observation was made right at where I was staying for the night. Winds over 60 MPH, hail up to 1", some covering the ground and entering the room of the motel when the door was opened, torrential rains, and very frequent lightning with close hits. Conditions causing the storm were surface convergence, an approaching area of strong low pressure, and strong winds / cold air aloft in a highly sheared environment. A 2009 Kia Forte was used to chase the storms. Documentation was HD video. A tornado watch was also in effect for the area until 8 AM CDT.

7). April 24, 11:30 AM - Observation and indirect penetration of an extremely severe and violent tornadic thunderstorm from northwest of, and to near Yazoo City, Mississippi in Yazoo County from highways 49 and 61 with the chase coming to and end near Highways 49 and 16. This storm was a violent, and long-track HP supercells storm, that originated in northeastern Louisiana, crossed the ENTIRE state of Mississippi, then weakened in western Alabama. The storm was also a very fast-moving storm, so getting in front of the storm was difficult. The storm core had large hail and very strong winds. The most tragic aspect of this supercell was the large long-track tornado it produced, with a 100-mile long path, and a width of 1.75 miles! A brief view of this tornado, although rain-wrapped, was encountered in the storm core, about 3-5 miles northwest of Yazoo City. Tress / other small debris was also noted falling OUT of the sky in this area. A path was chosen to divert to the northeast and around the storm because of the danger, coming back around to 49 and heading south into Yazoo City. Winds at least 70-75 MPH were encountered in this area, from the east and southeast. The damage path was encountered behind the storm, still in strong winds and rain, and much of the area south of town, near Highway 49 and 16, had catastrophic EF-4 tornado damage. The chase had to be aborted to help with clearing roads / assisting emergency personnel in Yazoo City. The storm containued to the NE out of sight thereafter, as I was helping with the victims of the storm. Unfortunately, 4 people were killed in Yazoo city, so this is NOT a happy chase log. Conditions causing the storm were surface convergence, an approaching area of strong low pressure, and strong winds / cold air aloft in a highly sheared environment (divergence aloft and strong veering of winds with height). Helicity in this area was also a staggering 1000 with CAPE near 3,000 (and EHI of near 19)! A 2009 Kia Forte was used to chase the storms. Documentation was digital stills HD video of the damage / emergency efforts. A PDS tornado watch was also in effect for the area until 1 PM CDT (and extended to 8 PM CDT).

This concludes the Chase Log for the US Great Plains, Midwest, and deep south tornado chase trip from April 21 through April 25, 2010. This chase summary includes a total of 7 strong / severe thunderstorms, out of which, 2 tornadoes were observed. One of the tornadoes was a violent long-track (EF-4) tornado that struck Yazoo City, Mississippi on April 24 with devastating, and fatal results. The main chase vehicle conducting all chases was a 2009 Kia Forte. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

GALLERY FOR APRIL 21, 2010

Here is all my chase gear, clothes, and electronics packed tightly into a mere two carry-on bags for the 5 day chase trip. Packing light and in a carry on saved time and threat of equipment damage. I always love the expressions on the TSA people at the airport when the bags go through the X-Ray machine!
Here is a picture of the chase rental vehicle, a 2009 Kia Forte, ready to go with equipment mounted and running. The electronics are all powered by a long cable that clips to the battery terminal, protected by its own fuses, and runs to the invertor, laptop, radio, and such in a simple and quick setup.

GALLERY FOR APRIL 22, 2010

Here is a picture of the first developing supercell storm southwest of Liberal, Kansas (near and northeast of Guymon, Oklahoma at the time (view is southwest). Note the "turkey tower" of cumulus in the foreground billowing upwards, then getting toppled over by the directional (and bulk) shear.
Approaching the supercell storm near Hooker, Oklahoma. Nice rain-free base becomes evident.
Here is a radar image (base reflectivity) of the supercell storm as it was southwest of Hooker, Oklahoma. The view is to the southwest.
Looking closely at the wall cloud and updraft region of the supercell, a funnel / possible weak tornado is visible (center). The view is also to the southwest.
Here is another funnel that developed as the storm drew a bit closer, with a rotating wall cloud (center). The view is to the west.
Here is another picture of the rapidly rotating wall cloud / funnel just before the storm became occluded and weakened. This was near Hooker, oklahoma along Highway 54. The view is to the northwest.
This is a picture of the anvil blowoff at high altitudes near Perryton, Texas just east of another supercell storm. The view is to the south, and the interesting thing is the upper-level divergence (difluence) can be seen as the anvils (one from the supercell out of frame to the right, and from the storms farther away) get farther apart as one proceeds eastwards (to the left in this picture).
This picture appears to be far away from the Paerryton, Texas supercell storm to be concerned (it's updraft is far to the right to the southwest in this picture). However, hail up to 1" is falling from the anvil of the storm and into the "clear blue" air, and actually covered the ground at one point!
Interesting shelf cloud associated with a multicell / HP storm north of Pampa, Texas while headed south along Highway 70. The view is to the south, and the inflow can easily be seen going from left to right.

GALLERY FOR APRIL 23, 2010

These interesting wave / rotor clouds (looks like mid-level HCR's) were encountered in the mid-levels over eastern oklahoma / western Arkansas. Most likely this is a result of directional shear in the atmosphere.
This is the visibility out the front windshield during one of the severe storm penetrations near Lonoke, Arksansas.
This is a base reflectivity radar of the supercell storm not far from Prescott, Arkansas. Notice the white circle of my GPS position (heading was SW along I-30 and into the core and rain-free area) - Yikes!
A poor-visibility view from inside the supercell core near Prescott while it was producing 70 MPH+ winds and hail up to 1".
Cloud to earth lightning strike on the backside of the thunderstorm complex from near Beck, Arkansas.

GALLERY FOR APRIL 24, 2010

Here is a picture of the door of my motel room and hail coming into the door in Texarkana, Arkansas in the early morning hours of April 24. This night-time severe storm was the very start of a tragic day of severe weather.
Here is a view of the back-sheared anvil of the violent HP supercell storm about 30 minutes before it struck the town of Yazoo City, Mississippi. The view is to the south, and taken from near Hollandale.
This is another view, looking to the southwest, when closer to the soon-to-be Yazoo City supercell. The dry-punch of air creates a clear slot that pushes into the unstable air in a highly sheared environment (not the blow-off in the top of the picture, and cumulus line).
Destroyed church in Yazoo City, Mississippi near the junction of Highway 49 and 16.
Major structural damage in Yazoo City, Mississippi just west of Highway 49.
High end EF-3 to EF-4 damage in Yazoo City, Mississippi.
Dazed - But otherwise OK - Yazoo City locals stand outside a building that was nearly completely destroyed by the tornado.
Locals wandering unscathed out of the hardest hit area of Yazoo city, along Old Benton Road. These people were very lucky, most likely because timely warnings were given for the storm, and they sought shelter in their basement / closet. Note the live downed powerlines in the foreground.
Freshly destroyed home on the south side of Old Benton Road, Note the ruptured water pipe creating a fountain.
Some Yazoo City locals, also lucky to be uninjured, standing aside an overturned (and mangled) pickup truck, as the first heavy equipment clears the way for emergency crews to enter the hard-hit areas off Old Benton Road.
The TVN (Tornado Videos) group of storm chasers was also on this storm, and also stopped to assist. Storm chasers do not like to meet one another in such dire places. It's a sad thing. The "Domonator" vehicle, very similar to the TIV, is also designed to penetrate tornadoes, but not ones as stong as this.
This is a chain-link fence after the tornado. The air flowing through this fence was filled with debris and "projectiles", which became trapped in the fence ... Try to imagine what would happen to anyone standing in this place during the tornado.
My part of the stop-and-help work was to help with clearing the roads of tree and other debris. Here a few locals were cutting up the fallen trees so they can be moved by a group of men. Each cut log section weighed hundreds of pounds ... But the tornado moved these as they were whole trees (along with vehicles, roofs, etc) as if they were blowing dust.
this road sign, all twisted and mangled, was no match for the 170 MPH+ core winds of the Yazoo City tornado. This was also one of many "objects" that moved around the tornado's debris field at aircraft speeds during the storm.
Destroyed bill board sign on the south side of Yazoo City near Highway 16 and along Highway 49.

GALLERY FOR APRIL 25, 2010

The painful reminder of the Yazoo City tornado disaster is mirrored on CN on one of the televisions at the Dallas Airport as I wait for my flight back to Florida. Going home with this in the back of my mind (having experienced the event first hand) is quite humbling.
The distinct signature of a thunderstorm updraft peeks above the turbulent high-altitude cirrus deck while flying over the northern Gulf coast and encountering the line of severe thunderstorms (near eastern Alabama at this point) on April 25. The white "dome" (lower-center) is the top of a thunderstorm updraft, probably 50 to 100 miles away. We were flying at about 38,000 feet.

CHASE LOG FOR MAY 8 TO MAY 13, 2010

Above is a map of the chase track and such from the period of May 8 through May 13, 2010. The inset in the upper-left shows the flight (green path) to and from Kansas City, Missouri and Fort Lauderdale, Florida. Kansas City was the "base city" for this trip, and a 2009 Kia Forte was used in all chases. The main map shows a blue "chase and travel" path, and includes the states of KS, MO, and OK. Each red "X" denotes an observation point of severe weather. The "][" symbol denotes a confirmed tornado that was observed. A total of 2,239 miles were put on the rental vehicle in the period from May 8-13.

CHASE SUMMARY FOR MAY 8 THROUGH MAY 13, 2010

This was a 6 day chase trip to the central USA with 4 days available for chasing and 2 travel days. I left Fort Lauderdale, Florida and flew into Kansas City, Missouri (with a stop in Orlando, Florida) on the evening of May 8 and picked up the rental vehicle, a 2009 Kia Forte, the same vehicle used in the last chase trip. I began the drive west into Kansas along I-70 and stopped for the night in Salina, Kansas. May 9 was not expected to be even a marginal chase day, so I spent most of the morning analyzing data and setting up the equipment in the chase vehicle. I decided that a good choice for May 10 (Monday's) target will be in south-central Kansas, from west of Wichita but not as far as Pratt. I pretty much headed south on I-35 to highway 54, then west to Pratt. I took a extra trip and visited Greensburg, Kansas to check how the rebuilding went 3 years after an EF-5 tornado destroyed the town in 2007. I headed back to Pratt and then south along Highway 281 to Medicine Lodge, a pretty good starting point for May 10.

Some elevated storms were noted on radar after checking in to Medicine Lodge, and with time to spare I headed east on Highway 160 for about 60 miles to check if anything interesting can be found within the high-based overcast. I headed as far east as I-35, but storm motions were very fast, despite a severe storm warning on one of the storms. The storms, if any, were very high based, and above a mid-level layer of clouds associated with the EML, so it was difficult to visually see them from any distance. I was able to tweak my equipment and get everything working, then I headed back to Medicine Lodge via Highways 166 and 49, then back along Highway 150 and into Medicine Lodge for the night.

The first major chase day of this trip was Monday, May 10. During this day, three severe thunderstorms were intercepted, two of which were significant tornadic supercell storms. The day started by forecasting early in the morning at Medicine Lodge and deciding the area from near Tonkawa to Enid may be a good first start for a chase target. I left Medicine Lodge, Kansas by heading out on Highway 160 to Harper, then south into Oklahoma on Highway 132, then east to Enid to check more data over lunch. Menwhile, the Storm Prediction Center had a high-risk outlook for north-central Oklahoma and eastward, with a 30% hatched tornado probability. Upon checking data, it was a good idea to work a bit west for expected initiation of severe storms. I headed north out of Enid on Highway 60, then west to Nash on Highway 64 to wait / check data. The SPC posted Mesoscale Discussion #507 and subsequent PDS (Particularly Dangerous Situation) tornado watch box #147 valid until 10 PM CDT. By about 2:30 PM, a small convective shower developed southwest of Lambert. This small storm would be the first violent supercell of the day.

The initiation was observed from west of Nash and along highways 64 and 58. The storm quickly intensified into a supercell storm, and I stopped farther north near Highway 11 and 38 while meeting up with some chasers (Chris Kridler and Scott Mcpartland). We headed north and east along E0090 road before breaking off. I continued east to stay ahead of the rapidly developing storm, which produced a large multi-vortex / wedge tornado near Medford and Wakita, and eventually towards Renfrow. I had to bail out of the tornadoes path south of Renfrow and take Highway 11 out of Medford to go east. I lost sight of the HP storm and a second attempt to catch up with it along Interstate 35 near Braman failed as it weaked / construction (exit was closed). I left the storm favoring another supercell near Ponca City, Oklahoma, about 25-30 miles to the south. This was at about 5:30 PM.

With no way to get back on I-35 south out of Braman, I chose Highway 177 down to Blackwell and east on Highway 60 to and past Ponca City. The storm was encountered east of Ponca City, and large hail and a possible rain-wrapped (weak) tornado was observed. Farther east, the "bears cage" of the storm was entered, with a very large rain-free base from south of Shidler and east to near Pawhuska. An additional two tornadoes were observed, one south of Shidler, and the other in the distance towards Pawhuska to the east. The storm weakened by about 7 PM. Another severe storm was encountered by heading up Highway 99 out of Pawhuska to the storm near Sedan, back over the border in Kansas. This storm was not tornadic, and it was allowed to continued off to the east as I headed east on Highway 166 to Highway 75 to go back south. Winds gusting to near 60 MPH were encountered in a non-convective wind, probably associated with the passage of the dryline boundary. I continued into Oklahoma and south to Highway 20, then headed west and northest into Ponca City for the night.

May 11 was to be a slight risk chase day, and with quite a bit of driving and refining positions, I was rewarded with two beautiful supercells and a brief tornado from the second one. I forecasted and decided on a target area anywhere from Seiling, Oklahoma to possibly as far south as Clinton. I wanted to stay true to my target and not abandon west-central Oklahoma had I chose to go south. I left Ponca City and headed west and south to Enid on Highways 60 and 64, stopping in Enid to check data. Two areas stuck out, one to the west (original target around Seiling) and another to the southwest. I was reluctant to go southwest because of a strong cap in place, near and south of I-40. A warm-front and dryline intersection was also progged to affect the northern option AFTER the southern storms will fire in the high CAPE environment. I left Enid, and headed west to Waynoka on Highways 412 and 281, then south to Seiling to wait a bit. I noticed the small cumulus was gone in that area, with some cumulus noted via satellite developing in SW Oklahoma.

I decided to drop south a bit by heading back east on Highway 60 then south on Highway 51, stopping in Watonga to again check data. The SPC had a 5% probability for tornadoes in a slight-risk area, and issued mesoscale discussion #517 and subsequent tornado watch box #151, valid until 10 Pm CDT. This matched nearly perfectly with my forecasted area(s). I continued to monitor satellite and still saw growth in cumulus to the southwest. I left Watonga via Highway 33, then south to I-40 on Highway 54. I positioned myself a bit west on I-40 and near Highway 183 to assess if initiation was going to happen. An area of agitated cumulus, and a small radar return was noted going up in SW Oklahoma. It was time to head south on Highway 183 through Cordell and check out the development.

The developing storm quickly became an LP supercell storm, and it was followed from south of Cordell to near Carter on Highways 152 and eventually 6 back up towards Elk City. The LP storm looked great for some time, then, to mine and about 200 other chasers' suprise, it basically shriveled into northing, leaving only an orphan anvil behind. I met up with Brian Morganti and folks with their tour group near Carter, and called the first LP storm quits and decided to work our way north back towards the warm front / dryline interaction. There was plenty of time to go back to I-40, then east to Highway 183 to go north. Upon reaching Highway 183 and passing through Arapaho, weak and linear development was noted along the warm front, which was draped along a WNW to ESE line near Putnam.

The effects of the dryline / warm front boundary became quickly evident as large towaring cumulus was quickly growing to the west once I got to near Putnam. I decided to head west on Highway 47 towards Leedey, and go north on Highway 34 from there towards Vici. The storm quickly became a supercell storm because of the boundary interections. I headed west on Highway 60 through Vici and towards Harmon and Arnett, targeting the updraft region of the intense supercell storm. A brief tornado was observed from a distance of a couple of miles over open country near Harmon. Ironically, this location is a mere 15 miles from Seiling, my original target for the day - Driving home the point that your FIRST target is usually the best. After that, the storm weakened to an LP supercell and slowly dissipated, lasting a while after sunset. I headed back in highway 60 to Vici and north of Highway 34 to Woodward, Oklahoma. I finished the day by traveling east and northeast on highways 412 and 281, through Waynoka and spend the night in Alva, Oklahoma.

May 12 was thee last day available for chasing and a relatively good setup existed from Oklahoma and into southern Kansas. I forecasted and found that a good play would either be in south-central Kansas (near Wichita) or in SW Oklahoma, both with a slight possibility for tornadoes, with the northern target being a supercell to linear evolution. The Wichita area was chosen becauswe the Oklahoma area would be too far (returning to FL from Kansas city the next morning). I left Alva and headed east along Highways 64 and 11 towards Medford, stopping near Wakita and Renfrow to survey some damage from the May 10 tornado. I continued east on Highway 11 to Blackwell for lunch and checking more data. It appeared the good area for the chase target was to be in and west of Wichita, Kansas, so a route was chosen north on I-35 to Wichita. A region of convergence and backed SSE winds was noted just west of Wichita, along with a slow-moving cold front / boundary stretching from a weak surface low in western Oklahoma to near Kansas City. A cap was in place, but began to erode by about 3 PM with the approach of an upper shoertwave.

At about 2:30 PM, the SPC issued MCD #527 for the area, and a large tornado watch #155 after that, valid until 10 PM CDT. The area was also outlooked in a slight-risk, and a 5% to 10% probability of tornadoes. By roughly 3 PM, the stalled front began initiating storms northeast of the surface low from NW Oklaghome near Alva to west of Kingman. A large HP supercell storm was intercepted with this activity near Kingman, and another later near Spivey, the first being close to producing a tornado (rotating wall cloud). The highways involved near Kingman were Highways 400 / 54 and southward along Highway 15 to near Spivey near Highway 42. After the second storm, the storms evolved into an outflow-dominant MCS with winds to 70 MPH. The chase was wrapped up at around 6:30 PM with a return along Highway 54 into Wichita then north on I-35 to Highway 254, then Highway 77, and Highway 50 to go east and northeast. I picked up I-35 into Kansas City, staying for the night off I-435 near Kansas City Airport.

Another severe storm blasted through the area before midnight, damaging signs and having winds over 70 MPH. I packed up the equipment, returned the rental car, and flew back to Florida the following morning (May 13) with a delayed flight change.

MAY 8 TO MAY 13 CHASE MAIN PARTICIPANTS

CHASER NAMEHOME CITYCALLSIGNCHASE DATESOCCUPATION
CHRIS COLLURASUNRISE, FLKG4PJN5-8 TO 5-13IT CONSULTANT

FORECASTING AND TARGET AREA - MAY 10

May 10 was the first (and very big) chase day on this trip. In the diagram above, we see a high-risk outlook for Kansas and Oklahoma issued by the Storm Predictions Center (SPC). In this area, a staggering 30% hatched tornado, 45% hatched hail, and 30% destructive wind probability was issued. In the middle image, PDS tornado watch box (Particularly Dangerous Situation) number 147 is shown. Notice the probability of all modes of severe weather (including violent tornadoes) is "high" across the board! To the far right are the store reports for May 10. Unfortunately, the high-risk verified and numerous reports of tornadoes, hail, and strong winds occurred. This activity includes the severe storms (including tornadoes) I was chasing, as well as a destructive tornado affecting the area of Oklahoma City and points eastward (again). Tornadoes appear as red dots, hail as green, and wind reports as blue dots. Excessivelt high winds and large hail (over 2") appear as a black square and black triangle, respectively.

FORECASTING AND TARGET AREA - MAY 11

May 11 was a slight-risk chase day, with a 5% probability of tornadoes as per the SPC (Storm Prediction Center products in the left image. The slight risk (and tornado probability) was due to an "triple point" where a dryline and warm-front intersect, and is clearly denoted by the MD (Mesoscale Discussion) #517 in the middle image. The right image shows a radar (reflectivity) image of a tornadic supercell storm that formed along that same "triple point", at that time, a bit farther north into NW / W-Central Oklahoma (the same storm that produced the brief tornado north of Harmon / west of Vici). A previous supercell storm (not shown here) developed earlier near Cordell, Oklahoma, but was not long-lived.

FORECASTING AND TARGET AREA - MAY 12

May 12 was the final active chase day of this chase trip. On this day, the SPC outlook was set to slight-risk with a 10% tornado outlook stretching from south-central Kansas to NW / N Central Oklahoma. The setup included a low-pressure system over Oklahoma, Dryline, and slow-moving cold front extending from the low in Oklahoma and northeastward into Kansas. The MD (Mesoscale Discussion) #527 shows the low, dryline, and frontal system involved. Subsequently, tornado watch box #155 was issued for a large area in Kansas and Oklahoma. My target was in south-central Kansas due to the position of the surface low as well as being close to Kansas City for my return trip the following morning.

SATELLITE IMAGERY - MAY 10-12

The diagram above shows the satellite imagery for the storms (either during upscale development or maximum intensity) on May 10, 11, and 12, respectively, from left to right. The left image is the most impressive in this set, with a powerful dryline (you can exen make out the dust kicked up to the left of the image) crashing into a Gulf of Mexico airmass and initiating severe storms and tornadoes. The large complexes of storms in north-central Oklahoma are the ones that produced the tornadoes near Wakita, Medford, and east of Ponca City. To the south, is the destructive tornado-producing storm that affected Oklahoma City and points east. In the middle picture, we see an isolated tornadic supercell forming at dusk in the vacinity of Harmon, Oklahoma on May 11 (time is UTC, so it's the following day on Greenwich Mean Time). The image to thr right shows the multicell storms that affected south-central Kansas and north-central Oklahoma on May 12 during the afternoon.

STORM RADAR IMAGERY - MAY 10

The diagram above shows some of the most impressive supercell radar images possible. The violent tornadic supercell storm that affected north-central Oklahoma on May 10 happened to pass very close to the Vance Air Force Base radar site (VNX). This was also the same storm (the first northern storm) I was chasing that day. The white "circle" in the two left images shows my position relative to the storm. The left image is the base reflectivity (in DBz) of the supercell, while the middle image shows the inbound-outbound (gate-to-gate divergence) velocities. A very impressive "flying eagle" signature appears in teh reflectivity image to the left, where the middle shows over 150 knots of divergence / shear, indicating a distinct TVS (tornado vortex signature). The large yallow "triangle" denotes the hail core of the storm (to or exceeding baseball sized). The striking image to the right shows my view towards the southwest at about the time these radar images were being sampled (developing wedge tornado with a width of a mile or more).

DETAILED LOG ALL CHASES

1). May 10, 4:30 PM - Observation of an extremely severe and violent tornadic thunderstorm in Grant County, Oklahoma from near Highway 81 and the town of Renfrow. The storm was a classic supercell thunderstorm that evolved to a violent HP storm that produced at least two tornadoes, both multi-vortex in nature, and one a wedge tornado west of Renfrow, Oklahoma. Both tornadoes were observed, one (near Wakita, Oklahoma) from a distance, and the multi-vortex / wedge from a few miles directly in its path. Large hail was also observed falling from the anvil of the storm, up to 1", with 50-60 MPH inflow winds. The main core of the storm was not penetrated. Light rain and frequent lightning was also noted with the supercell. Damage was anywhere from downed trees to major damage to homes in the tornados path, particularly near the town of Renfrow. The storms were caused by an intense (Colorado) low-pressure system, upper-level low, dryline and warm-front (triple-point) interactions, and surface heating. Documentation was digital stills and HD video. A 2009 Kia Forte was used to chase the storm. A PDS tornado watch was also valid for the area until 10 PM CDT.

2). May 10, 6:30 PM - Observation of an extremely severe and tornadic thunderstorm in Osage County, Oklahoma from near Highway 60 and from Ponca City to near Pawhuska. The storm was a large classic supercell thunderstorm with multiple areas of rotation. An indirect penetration was executed across the storm core and rain hook, and into the rain-free (mesocyclone) of the storm. Hail up to 2" was observed, with very heavy rains, lightning, and 60-70 MPH wind gusts. A possible tornado, although rain wrapped but weak, was encountered west of Burbank, Oklahoma. Leaves / tree debris was also noted falling from the sky. Farther east, two tornadoes were observed, one at a distance, to the east near Pawhuska, and another closer to the north of Highway 60 near Shidler. Tree damage and downed powerlines were encountered with this storm. The storms were caused by a strong low-pressure system, upper-level low, approaching dryline, and surface heating. Documentation was digital stills and HD video. A 2009 Kia Forte was used to chase the storm. A PDS tornado watch was also valid for the area until 10 PM CDT.

3). May 10, 7:30 PM - Observation and penetration of a very severe thunderstorm in Chautauqua County, Kansas from near Highway 99 and Highway 166 near the town of Sedan and eastward to southeast of Havana. The storm was a supercell storm, possibly formerly tornadic, evolving to an intense line segment as the dryline boundary surged in from the west. The storm had winds gusting near 60-65 MPH, torrential rains, lightning, and small hail. The storms were caused by a strong low-pressure system, upper-level low, dryline, and surface heating. Documentation was digital stills. A 2009 Kia Forte was used to chase the storm. A PDS tornado watch was also valid for the area until 10 PM CDT.

4). May 11, 5:30 PM - Observation of a short-lived but severe thunderstorm southwest of Cordell, Oklahoma along Highway 55 and towards Carter in Beckham county. The storm was an LP supercell developing ahead of a dryline bulge. During its high point, it probably had dime-sized hail and strong inflow winds (over 35 MPH). The core of the storm was not penetrated. The strong capping inversion, and lack of substantial forcing to over come it, caused the storm to quickly dissipate, leaving only an orphan anvil behind. The storm was caused by a dryline, upper trough, surface trough, and surface heating. Documentation was digital stills and HD video. A 2009 Kia Forte was used to chase the storm. A tornado watch was also valid for the area until 10 PM CDT.

5). May 11, 8:30 PM - Observation of an extremely severe and tornadic thunderstorm west of Vici, Oklahoma along Highway 60 in Ellis and Woodward counties. The storm was a supercell thunderstorm, starting out as classic (or even HP), and weakening to LP before dissipation. The core of the storm contained hail to 2", but was not penetrated. A tornado was observed in the rain-free area as well as a large RFD clear slot northwest of Harmon. Frequent lightning and 40+ MPH inflow winds were encountered as well. The storm had a very striking visual appearance (BWER "vault" and "barber pole" updraft striations) during its LP phase near dusk. The storm was explosively developing on the intersection of the dryline and warm-front boundaries, and was supported by strong winds aloft, an upper trough, a low pressure trough, and surface heating. Documentation was digital stills and HD video. A 2009 Kia Forte was used to chase the storm. A tornado watch was also valid for the area until 10 PM CDT.

6). May 12, 4:30 PM - Observation of a very severe and possibly tornadic thunderstorm near Kingman, Kansas in Kingman County near Highways 400 / 54 and east of Highway 14. The storm was an HP supercell storm, developing in a broken line / cluster of severe storms. The core of the storm, containing hail up to 3" was not penetrated, but hail ahead of the storm to golf-ball size was observed. Heavy rains, 60 MPH winds, and frequent lightning were encountered. A large wall cloud was observed near Kingman before the storm became outflow dominant. The storm was caused by a low pressure system / trough, upper trough, surface heating, and a frontal boundary / gravity-wave interaction. Documentation was still photos and HD video. The chase vehicle was a 2009 Kia Forte. A tornado watch was in effect for the area until 10 PM CDT.

7). May 12, 6:00 PM - Observation and penetration of another very severe thunderstorm near Spivey, Kansas in Kingman County near Highways 42 and 14. The storm was an HP supercell storm, embedded in a broken line / cluster of severe storms. The storm was indirectly penetrated, and a wall cloud / large rain-free base was observed. The storm quickly became outflow dominant, and produced winds to 70 MPH (blowing dust / gustnadoes were observed ahead of the storm gust front). Small hail, torrential rains, and frequent lightning with some close hits were also observed. The storm was caused by a low pressure system / trough, upper trough, surface heating, and a frontal boundary. Documentation was still photos and HD video. The chase vehicle was a 2009 Kia Forte. A tornado watch was in effect for the area until 10 PM CDT.

8). May 12, 11:30 PM - Observation of a very severe thunderstorm from a hotel along Interstate 29 and just east / south of Interstate 435 in the northern sections of Kansas City, Missouri in Platte County. This severe storm was observed from a motel while wrapping up the chase trip, and was an intense blow / squall line segment. Winds over 70 MPH with sideways torrential rains, small hail, and frequent lightning with some close hits were observed. A Mc Donalds sign was damaged across the parking lot during the storm. The storm was caused by a cold front and attendant low-pressure system, upper level low, and warm air advection (low-level jet aloft). Documentation was HD video. A 2009 Kia Forte was used in this storm chase. A tornado watch was also valid for the area until 12 AM CDT.

This concludes the Chase Log for the US Great Plains and Midwest storm chasing trip from May 8 through May 13, 2010. This chase summary includes a total of 8 interceptions with 8 severe thunderstorms observed. As many as 7 tornadoes (5 confirmed) were observed, two of which were very destructive. The main chase vehicle conducting all chases was a 2009 Kia Forte. is TBD. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

GALLERY FOR MAY 8, 2010

Here is a picture of an intense multicell cluster of strong and severe storms north of the Florida / Alabama coast while flying from Orlando, Florida to Kansas City, Missouri. The airliner is circumnavigating the severe storms at an altitude of 34,000 feet, providing this great view of the storms (and lightning visible in broad daylight) from the right side of the aircraft (view is to the north).

GALLERY FOR MAY 9, 2010

Here is the SAME chase vehicle (a red Kia Forte) I used on my previous chase trip - Same color too - Ready to start chasing and equipment installed.
Interesting sign on the eastern part of Greensburg, Kansas. This was a town that was devastated in early May of 2007 from an EF-5 tornado. The entire town was rebuilt with energy efficiency in mind ... And a sense of humor too!
Although not a very active chase day, with gloomy and grungy weather most of the day, some fast moving elevated storms managed to show up on radar by early evening on May 9 in extreme north-central Oklahoma near I-35.

GALLERY FOR MAY 10, 2010

Here is a picture of the first major supercell storm during its very early stages of initiation. This storm was southwest of Vance, Air Force Base in northern Oklahoma. Beleive it or not, this small and innocent looking storm will eventually grow to a violent supercell and produce multiple tornadoes, including a multi-vortex / wedge tornado later on near the town of Rentrow.
This is the same supercell storm's updraft and anvil blow-off as it approached Wakita, Oklahoma and just when it started producing tornadoes. The view is to the southwest and I am about 10 miles WSW of Rentrow.
The supercell storm intensifies explosively and this dusty and wide wedge tornado develops to the southwest of Rentrow, Oklahoma. Getting this shot was literally a few minutes before the tornado, moving to the ENE at 60-MPH, would have reached my position.
Here is a view of the multi-vortex / wedge tornado just before it beared down on Rentrow, Oklahoma. At least two sub-vortices (smaller tornadoes) can be seen "dancing" within the main tornado circulation.
Doppler radar reflectivity image from Vance Air Force Base of the Wakita / Medford supercell during maximum intensity. This is got to be one of the most impressive radar images of a violent supercell I have ever seen. Note the "eye" like feature in the hook "knob" to the lower-left of the supercell!
Another violent supercell produces hail over 2 inches in diameter east of Ponca City, Oklahoma along highway 60. This storm also produced tornadoes, one near Pawhuska and another south of Shidler.
First view of a tornado on the ground near Pawhuska, Oklahoma off in the distance (image is enhanced, and the tornado silhouette is in the center of the image) from the supercell storm east of Ponca City. The view is to the east.
Another tornado from the supercell storm east of Ponca City and south of Shidler, Oklahoma. The view is to the north, and this tornado is NOT the one near Pawhuska above (this supercell had multiple mesocyclones / tornadoes).
Another view of the tornado in its later stages and becoming slightly rain-wrapped south of Shidler, Oklahoma.
Large wall cloud associated with the older mesocyclone to the west of Shidler, Oklahoma just as the tornado south of that area formed from the new meso.
Beautiful line of heavy cumulus, illuminated by the setting hazy sun to the west, associated with the passage of the potent dryline looking east north of Tulsa, Oklahoma.

GALLERY FOR MAY 11, 2010

Here are two of the University of Massachusetts DOW (doppler on wheels vehicles) headed down Highway 183 to an initiating LP supercell southwest of Cordell, Oklahoma.
This is a picture of an LP supercell storm that has initiated along a bulge in the dryline southwest of Cordell, Oklahoma. The small single updraft has an impressive anvil "crown" spreading overhead. The supercell updraft region is to the lower right. The view is to the west.
About an hour later, the LP supercell southwest of Cordell, Oklahoma basically evaporated into nothing. Convective inhibition / lack of forcing was the culprit leading to the demise of the LP storm. The view is northeast.
One of the storm chasing tour groups, with storm chaser Brian Morganti, second from right, scratching his head and deciding to go north after the LP storm southwest of Cordell "vanished".
Farther north into nortwestern / west-central Oklahoma, a triple point (warm front and dryline intersection) causes initiation of more storms in a focused region. Once developing supercell breaches the "cap" and explosively develops west of Leedey, Oklahoma. The view is to the west.
Here is a view of the same supercell undergoing explosive intensification near the dryline / triple-point. The view is to the west and northwest, and was taken a mere 15 minutes after the previous photo above.
The supercell storm moves northeast away from west of Leedey and northwest of Vici. This brief tornado was caught from along Highway 60 between Vici and Harmon, Oklahoma. The storm weakend to LP and dissipated about an hour later.
Here is the same supercell, still "anchored" on the triple-point, weakening to LP (low precipitation) with a spectacular "barber pole" updraft column at dusk about 10 miles south of Woodward, Oklahoma.

GALLERY FOR MAY 12, 2010

Damage to a farm stead near Wakita, Oklahoma. This damage was done by the edges of the circulation of the large tornado that went through the area on May 10.
Here are some of the TVN (TornadoVideos.Net) group headed north on I-35 into Wichita, Kansas. The "Dominator" vehicle, with Reed Timmer, is in the lead.
Here is a picture of my dewpoint / temperature sensor console, showing a dewpoint of at least 70 degrees F (lower left). Such high dewpoints indicate that moisture from the Caribbean / Gulf of Mexico has advected into the central US.
Severe storms, with embeeded HP supercells, explosively develop along a slow-moving cold front west of Wichita, Kansas. The anvil / mammatus can be seen overhead with agitated cumulus in the lower levels.
This is the inflow notch into an HP supercell storm, developing in the severe storm cluster, near Kingman, Kansas. A possible funnel is in the center of the picture.
The same storm, now northeast of Kingman, Kansas, during evolution to an outflow dominant MCS. The mescocyclone is still present in the dark area in the center of the picture, but cold outflow is undercutting it, precluding the development of any tornadoes.
The gust front and shelf cloud of the now outflow-dominant storm northeast of Kingman, Kansas.
The storms become outflow dominant, creating a large gust front and a microburst can be seen here kicking up a dust plume. This is near Kingman and west of Wichita, Kansas.
This feature, looking east towards Wichita from near Kingman, shows a possible gustnado (swirling dust picked up by a strong gust front).
Interesting RFD cleat slot on the "rotating head" cell on the north side of the outflow-dominant bow segment. The view is to the north.
A severe thunderstorm, associated with a bow-segment of severe thunderstorms, blasts through the area north of Kansas City near the airport (near my motel) during the late night of May 12. Some signs, including the Mc Donalds sign here, were damaged by the storm, with winds exceeding 70-MPH.

GALLERY FOR MAY 13, 2010

First light the next morning on May 13, after severe storms rolled through late at night, north of Kansas City and a damaged Mc Donalds sign.

CHASE LOG FOR MAY 18 TO JUNE 1, 2010 MAIN CHASE EXPEDITION

Above is a chase map for the entire chase trip from May 18, 2010 through June 1. The upper-right inset shows the chase area involved in the central USA and the flight to and from Fort Lauderdale, Florida to the "base" city of Dallas, Texas (with a stop in New Orleans, LA going out and Houston, TX returning). The symbol legend is in the lower-left, and any red "X" denotes a severe storm observation, while the green tornado symbols "][" represent a tornado / significant funnel observation. Any red "?" denotes a failed target chase (where the preferred storm-of-the-day / target area was not reached due to time / distance constraints and / or forecasting errors). There was a total of 15 travel days, of which, 13 of these days were available for chasing (day 1 and Day 15 were travel days). In these days, there were 9 chase days, 2 travel / down days, and 2 "bust" days (where a target could not be reached in time for storm interception). The two "bust" (failed-chase) days were May 21 and May 31. The storm intercept team involved for this trip consisted only of myself and was be "based" out of Dallas, Texas where I flew out to on May 18, 2010 and chase until June 1, 2010. The total mileage for this trip was 10,424 miles, as the above map does NOT show re-traced paths and / or country roads (AKA: "Bob's" / dirt roads). To put this distance into perspective, this is more than "driving" from Los Angeles to Tokyo, Japan then to Sidney, Australia (if there was a bridge across thre Pacific)! Such a staggering distance put on a rental vehicle in 2 weeks is basically running in circles from state-to-state solely for the pursuit of severe weather!

MAY 18 TO JUNE 1 CHASE MAIN PARTICIPANTS

CHASER NAMEHOME CITYCALLSIGNCHASE DATESOCCUPATION
CHRIS COLLURASUNRISE, FLKG4PJN5-18 TO 6-1IT CONSULTANT

ABOUT THIS STORM CHASING LOG

The image above is a comprehensive collaberation of all storm reports as per the Storm Prediction Center (SPC) from the period of May 18, 2010 through June 1 (the entire length of this chase trip). At least 2004 severe weather reports ocurred across the USA during this time-frame. The eerie depiction and shape of "Tornado Alley" can also be easily discerned from this diagram, with many of the tornado reports (red dots) appearing up and down the nation's mid-section. It is completely impossible to keep up with ALL of these tornado events, especially with me being a solo chaser this trip out (examples are May 24 and 31, where I simply could not make the tornadoes those days), but I suceeded at catching MANY storms, making this trip one of the better ones.

The following entries are all storm chases and interceptions performed in the Midwest United States from May 18, 20010 to June 1, 2010. This log is based on a solo effort of a storm chasing team. Members were myself - Chris Collura (Florida Skywarn storm spotter code B036 - KG4PJN). The main chase vehicle was 2010 Kia Optima. States chased (includes travel states): CO, KS, NE, OK, SD, TX and WY (7 states). Total mileage: 10,424 miles!.

This is a chase log for any chases during 2010 in the Midwest and Central United States that were conducted as "spot" chases during or do not have a dedicated page for them. Each chase section within this area will have its own details and such for that particular chase. This area was set up in the late spring of 2010 and is for any chase that was conducted in the US Plains and Midwest. Equipment use in such chases range from cell phone to HAM radio communications, digital / still cameras, video (SD) and high-definition (HD) camcorders, and data logging / GPS via laptop computer. Storm chasing involved driving in harsh conditions and / or for long periods of time.

All chases and observations are in chronological order and a chase number is assigned to each entry. Please bear in mind that all observations adhere to modern storm analysis standards and do not include all storms that occurred in a given area for a particular chase period.

Any kind of storm such as a thunderstorm, tornado, waterspout, tropical cyclone, and extratropical storm can be chased or observed. I have tried to keep this log of any storms that I have observed as accurate as possible, while using terms and expressions to abide by those used by most meteorologists and storm spotters today.

Storm chasing and observation can be extremely dangerous and may result in serious injury or death. I have received intermediate and advanced training for storm spotting in 1996. I strongly urge anyone who is to try their hand at storm spotting to get training before doing so. You must also have a good understanding of meteorology and storm dynamics. "If you don't know what you're doing, Don't do it!" Contact your local National Weather Service office for information on storm spotting and about training to become a Skywarn storm Spotter.

CHASE SUMMARY FOR MAY 18 THROUGH JUNE 1, 2010

This was a two-week long chase trip (15 total days, with 13 of them available for chasing and two travel days) starting with a flight from Fort Lauderdale, Florida to Dallas, Texas (with a stop-over in New Orleans) on May 18, and chasing in the central USA with a return to Florida on June 1. After getting into Dallas, Texas a bit late on a delayed arrival, I picked up the rental vehicle, a 2009 Kia Optima, and decided to head north out of Dallas on I-35 to spend the night in Oklahoma City. This would put myself in an easy position for the next day, which turned out to be a high-risk (again) chase day.

May 19 was a high-risk chase day in which a long-track supercell storm was followed quite a ways across several Oklahoma counties, with up to three tornadoes observed during the chase. I forecasted in the morning and set up the chase vehicle, deciding on a target area from around Clinton. I headed west on I-40, and had lunch in Clinton, and found out that I really did not need to adjust the target very much. A stationary boundary and dryline met just to my west (a triple point) and a low presssure system was pushing eastward into western Oklahoma. SPC had the area outlooked in another high-risk, with a 30% hatched tornado, 45% hatcvhed wind, and a staggering 60% hatched hail probability. MCD #623 and subsequent PDS (Particularly Dangerous) tornado watch box #190 were issued after 2 PM for these areas. Convective initiation began very close to the target area, near Leedey and southwest of Camargo, which was a quick trip west of Clinton by heading north then west on Highway 33. A tornado was observed in this area as the supercell matured. I worked my way east along highways 33, 270, and finally 105 through Guthrie, observing two more possible tornadoes (these were not as good contrast as the first / rain wrapped). I finished chasing when the storm gusted out (evolved from an HP supercell to an outflow dominant MCS) near Tryon. I worked my way south a bit, observing some flash flooding, then untimately west near the I-44 corridor back to Oklahoma City for the night.

May 20 was a rather frustrating start and end to a chase day, however, two beautiful HP supercells were intercepted in Navarro and Freestone counties in NE / Central Texas later that day. I rather hastingly left Oklahoma City at about 9:30 AM and headed east on I-40, expecting to drop south into NE Texas where the target area (based on my forecasting / SPC outlooks) was. I passed southward using Highways 59, 270, and 271, winding through the mountains in SE Oklahoma, finally reaching I-30 by mid afternoon in NE Texas. Supercell storms, some with confirmed tornadoes, were developing to my SW at that time, so reaching them in time was going to be a challenge. I continued south and west to near Athens, with Highway 31 being the intercept course for the storms (towards powell and south to where the two storms of the day were intercepted near Fairfield and Wortham). The chase was wrapped up by heading north on I-45 into Dallas, then north on I-35 for the night in Oklahoma City. I was cited for speeding in Oklahoma City a mere ONE MILE from my motel after I missed a turn and got "lost" off I-44 around midnight ... This was after religeously obeying the speed limit during a 500+ mile long 12 hour chase this day - It always "gets you in the end".

The hopefully short streak of lousy chase luck continued on Friday, May 21, with a highly anticipated target area in northeastern Colorado pretty much blown due to convective inhibition (a "cap") and a horrible delay due to construction that dasjed any hopes of intercepting storms north of the target area. I left Oklahoma City at about 9 AM with a forecasted target area of northeastern Colorado and points northward if necessary. I headed west on I-40, then northwest along Highway 281 into Woodward then Highway 270 to 83 and northward into Liberal, Kansas. The main target area was to be in NE Colorado, but seemed to keep shifting northward throughout the day, and wound up being in east-central Wyoming by late afternoon. My chase track headed west on I-70 from Goodland, Kansas and north on Highway 385 just as supercell storms (with confirmed tornadoes) were initiating about 150 miles or so to my NW. To make matters worse, MAJOR construction on Highway 385 pretty much eliminated me being able to reach anything worthwhile. The atmosphere remained stoutly capped over NE Colorado. This day only gave me 500+ miles of driving and a sunburn, and a more deeply-seated hatred towards road construction. I aborted the chase at around sunset, and abandoned Highway 385 near I-80, and headed back east to North Platte, Nebraska for the night.

May 22 was a chase day to remember for a very long time, and a night-and-day turn around from a day or so of prior bad luck. This day started with forecasting and leaving North Platte at about 9 AM with an initial target of central South Dakota. I left by heading north on Highway 84 pretty much all the way into South Dakota, stopping in Valentine, NE and Murdo, SD on the way to check data. The area of interest was a warm front / boundary draped across South Dakota to the northeast of Pierre. I continued to the NE of Pierre and waited near Highways 14 and 83 for some time. It became evident that convective initiation was dependant on the erosion of a capping inversion. This erosion became evident by 4 PM, as I met with storm chasers Jeff Pitrowski and others near the junction of Highways 14 and 83. Small cumulus went up northeast of this area southwest of Salby. Meanwhile, SPC, which had this area in a slight-risk and 10% hatched tornado probabilities, issued mesoscale discussion #662 and subsequent tornado watch box #202 for the area valid until 1 AM CDT (the following day). Supercells developed rapidly from the enhanced cumulus, and one storm became a violent cyclic supercell producing multiple tornadoes. Nearly all of these tornadoes, I counted a dozen, were significant, with one violent wedge tornado affecting the area north of Bowdle, SD with a farmstead and transmission powerlines dessimated by the passage of the wedge, which was up to a mile-wide at times! The storm continued cycling eastward north of Highway 12 until just west of Aberdeen, SD, where it became multicellular. I wrapped up the chase in Aberdeen for the night, ending this incredible chase day.

May 23 was another active chase day, but involved a very long drive to northwest Kansas for the forecasted target area. I left Aberdeen, SD at about 9 AM, and headed west on Highway 12 to 83. I stopped at Bowdle, SD and met up with Tim Samaras and members of the TWISTEX research team for a damage survey of the farmstead hit by the tornado a day earlier (with permission from the owners and sheriff escort). After the damage survey, which lasted a little over an hour, I continued south and west along Highway 83 through Pierre, SD. I stopped in Murdo, SD for a late lunch and checked data again. It appeared a good target will be in SW Nebraska and into NW Kansas. The SPC had this area in a slight risk with a 5% probability of tornadoes. I crossed into Nebraska, and met up with chaser Daniel Shaw near Valentine, and we both chased into Kansas on Highway 84 until we reached Oakley. The SPC issued a mesoscale discussion (MD #674) and subsequent tornado watch box #207 for a good portion of my target area in Kansas. A severe thunderstorm with hail and high winds was encountered south of McCook, then some supercell storms farther southwest. At least two tornadoes were observed, one north of Oakley, and another southwest Atwood and northward of Bird City. We continued west on Highway 36 then north to near highway 34 where we ended the chase. I continued back to Highway 84, and north into North Platte, Nebraska for the night to adjust for the possible target farther north for May 24.

May 24 looked like it would be another outbreak-type severe weather day, with another hope of seeing significant tornadoes, but wound up being a frustrating day with the wrong cluster of outflow-dominant storms being intercepted. I left North Platte, Nebraska at about 9:30 AM, and headed north on Highway 83 and then on 97, targeting the area in NW to North Central Nebraska / South Dakota (roughly around Mission, SD). The major problem with the forecasting for this day was the very large target area, with two areas of storms expected ... One to the west in NE / SD and another near the warm front farther north in central SD to the northeast of rapid city. SPC had a moderate risk (with a 15% hatched tornado probability) and issued mesoscale discussion #690 and subsequent tornado watch box #213 valid until 8 PM MDT. The latter target would probably not have been reachable because storms developed there early (2 PM) but became tornadic by 3 PM. To mame matters much worse, I became completely blind to any data while passing through the Pine Ridge Indian reservation (highway 18) from Whiteclay to Oelrichs had no data nor cell service. Once to Oelrichs on Highway 385, and observing outflow-dominant storms (developing squall line, not the expected supercells), I learned the northern target produced very large tornadoes, almost 200 miles to my north (near Faith, SD). I headed south on 385 through Chadron to try to find any southern supercell storms in the developing squall line. One intense embedded supercell storm was encountered near Hemingford, NE and another near Hay Springs. I ran across chaser Dan Shaw again, and caravaned with him the rest of the chase. The storms evolved to a squall line, and it was followed from Highways 20 and 391 into South Dakota and eastward all the way to near Mission on Highway 18. The chase ended in Mission. I went south on Highway 84 for dinner in Valentine, NE then south to North Platte for the night.

What was expected to be an off day turned out to be a major chase day for May 25, with a suprise chase setup in SW Kansas / Eastern Colorado and two supercells observed, the second storm producing at least SEVEN tornadoes during its life cycle (5 were land spouts, and the subsequent 2 mesocyclone spawned). I started the day by forecasting a target area in SW / W Kansas near the KS / CO border. SPC also had this area outlooked, with a 5% tornado probability. I left North Platte and headed straight down Highway 83 until I reached Oakley, Kansas where I went west to Highway 25 and south to Highway 160, where storms were observed initiating to my southwest. SPC issued Mesoscale Discussion (MCD) #710 and subsequent severe thunderstorm watch box #222. My target area was a bit on the northern regions of the MCD and watch, favoring better shear and a triple point with the dryline and a boundary. The first storm was encountered near Johnson City and into Colorado along Highways 116 and 89. The first storm was short lived and the chase track shifted to a better storm up north using Highway 89, stopping for fuel in Holly, and continuing north on county roads 35 and 37. The second supercell was first encountered near Towner / Sheridan lake, Colorado and followed eastward near and along Highway 96 / County Road D until north of Scott City, Kansas. I also ran into chaser Jim Reed while near Towner. Five landspout tornadoes were observed, followed by two tornadoes, as well as hail covering the ground like snow. I finished chasing this second supercell after dark, shot some lightning off Highway 96, then headed back to Highway 83 and north to I-70, and west into Colby for the night.

May 26 was another good chase day in northeastern Colorado, and a beautiful supercell was intercepted, with an onset of mild food poisoning waiting until I was finished chasing. I forcasted a target for NE Colorado, packed up, and left Colby at about 9:30 AM and headed west on I-70 to near Genoa (avoiding Highway 385 and construction). I headed north on CR 31 to near Lindon, west on Highway 36 to Last Chance, then north on Highway 71 to wait and check more data near Fort Morgan / Akron. During late lunch, I noticed a cell developing northeast of Denver, about 65 miles to my SW. It appeared this would be the main storm of the day, so I went southwest to meet it on Interstate 76 and south to just north of Bennett. I ran into several chasers, including Verne Carlson and Scott Blair. The storm was followed from there, slowly northeast, until it weakened near Wiggins near and along Highway 52. I started feeling ill so I wrapped up the chase when the supercell weakened and headed for Denver via county roads until I-70 and into town for the night. I became quite ill with mild food poisoning / stomach problems (even vomiting). I settled in on the north side of Denver as the next couple of days may be off days.

May 27 was an off day, and was spent in Denver, Colorado and included a visit to Pikes Peak (down I-25 and to Highway 24 west of Colorado Springs. I spent that night in Denver and left the next day, May 28, for a reposition to NW Nebraska anticipating storms on May 29. On May 28, I left Denver and headed up I-25 into Wyoming, then east on Highway 18 then Highway 20 into Velentine, Nebraska for the night. This leave a wide window of options when chasing resumes on May 29.

May 29 was a marginal chase day, with some severe weather encountered in Grant, Cherry, and Hooker counties in Nebraska. The day started with forecasting and a plan of target from Velentine, Nebraska. A slow moving cold front and low pressure system was found across SW to central Nebraska, and a primary target area of Hyannis, Nebraska in Grant County was chosen. I left Velentine at about 11 AM by heading west on Highway 20 and south to Hyannis on Highway 61. I checked data in Hyannis and this was ther place to be, with a stalled / slow moving front, and convergence area. Shortly after my arrival, the VORTEX II team basically "invaded" the town! The SPC had a slight risk in place for a large area, including southwest and central Nebraska, with a 2% tornado and 30% wind / hail outlook. Mesoscale discussion (MD) #745 and subsequent severe thudnerstorm watch box #235 was also issued for the area, with the watch valid until 11 PM CDT. Storms initiated to the north of Hyannis at about 4 PM CDT, and developed eastward, forming a large MCS / cluster of strong and severe thunderstorms. I chased the storms near and north of Highway 2 until they neared highway 83 north of Thedford andd called it quits at about 8:30 PM. I headed south on Highway 83 through North Platte and into Kansas, spending the night in Colby.

May 30 was another low-end slight risk chase day, with north-central to central Oklahoma being the forecasted target. I left Colby around 9:30 AM and headed east on I-70 to Hays, then south on Highways 183 and 1 throught southern kansas and Highway 34 into Woodward, OKlahoma for lunch and to check data. It appeared that the west-central Oklahoma area would be faavorable for storms, but enroute on Highway 34 near Leedey, I decided to turn around and head for North Central Oklahoma. The SPC had the area in a slight risk with only a 2% tornado probability, so the focus for the day was hail and wind (both were outlooked at 15%). Mesoscale Discussion (MD) #750 was issued, then severe thunderstorm watch boxes 236 and 237, with the latter being for North-Central Oklahoma. A weak surface low was noted in West-Central Oklahoma with a shear axis (wind shift line) ahead of the low and juxtaposition to the slow-moving cold front. This area was also primed for southern-most storms in an on-going squall line in Kansas by evening, yielding the most promise for supercell storms. Two supercells were intercepted after making the final adjustment to chase in Northern / Central Oklahoma, one near Nash and the other south near Crescent City. These storms were mainly west of I-35, near highways 33, 64, and 74. The chase was wrapped up at dark by heading east along Highway 33 to I-35, then into Oklahoma City near I-44 for the night.

May 31 was a rather painful day because there were tornadic storms that formed in SE Colorado, west of the expected target area for the day, which was deemed too far to reach in time from Oklahoma City. I left Oklahoma City at about 11 AM and started west and northwest, targeting the area around Guymon, Oklahoma. I stopped in Woodward, OK and after checking data there, the promising area for supercells would be about 150 miles farther NW into SE Colorado. SPC had only a 2% tornado outlook and a slight risk for the area, centered on the OK Panhandle. Regrettingly, and tired after two weeks, I decided the low tornado chances were not worth (let alone possible) to go farther into SE Colorado. I turned around at Woodward, and headed back to Oklahoma City (had I even been on the Colorado storms, it would be impossible to make my return trip from Dallas, TX on June 1 the next day)! Well, the distant storms I turned my back on would up producing MULTIPLE tornadoes, all significant and photogenic, from Se Colorado to the extreme OK Panhandle. I spent some time at the Oklahoma City Memorial, then packed up my gear for my return to FL on June 1.

June 1 was the last day and my departure day. Severe storm chances existed, but in Nebraska / Iowa, for this day. I left in the morning from Oklahoma City to Dallas, Texas and flew back to Fort Lauderdale, Florida on an evening flight out of Dallas with a stopover in Houston. I learned in Houston (during my stopover) about a rather serious health issue back home with my mother (possible cancer). All in all, this was a VERY successful chase trip, with nearly all the days having activity, and only my limits as a solo chaser / distances becoming an issue.

DETAILED LOG ALL CHASES

1). May 19, 3:00 PM - Observation and indirect penetration of an extremely severe and tornadic thunderstorm from its point of initiation in Roger Mills County, Oklahoma from northwest of Leedey to its demise well to the east of Guthrie in Lincoln County near Tryon. The chase track was generally along Highways 33, 270, and 105. The storm was a supercell thunderstorm that started out as a classic supercell which evolved to HP. Three tornadoes were observed with this supercell, the first one, and the most visible, from near Leedey, another near Eagle City, and another from near Kingfisher to west of Guthrie. The storm came very close to producing a tornado in Guthrie, but only had a rapidly rotating wall cloud there. The two latter tornadoes of the three were rain wrapped during the storms HP stages. The storm also contained hail to baseball sized (or larger), torrential rains, 70-MPH winds, and frequent lightning. The storm core was not directly penetrated, so hail to quarter sized, heavy rains, and winds around 60 MPH were encountered. Conditions causing the storms were a low pressure system, upper trough, dryline / boundary interactions, and surface heating. A 2009 Kia Optima was used to chase the storms. Documentation was HD video and digital stills. A PDS tornado watch was also valid for the area until 10 PM CDT.

2). May 20, 5:30 PM - Observation and indirect penetration of a very severe, and possibly tornadic thunderstorm near Fairfield, Texas in Freestone County and between north of highway 84 and south of 287. This storm was an HP supercell storm, and its main core, containing baseball-sized hail, was not penetrated. Winds gusting near 60-MPH, heavy rains, frequent lightning with some close hits, and hail to quarter sized was encountered. A large rotating wall cloud was observed on the inflow side of the storm with an RFD feature as well. The storm was caused by the interaction of an outflow boundary and stalled cold front, surface heating, and an upper trough. Documentation was HD video and digital stills. A 2009 Kia Optima was used to chase the storms. A tornado watch was also valid for the area until 9 PM CDT.

3). May 20, 5:30 PM - Observation and penetration of another very severe, and possibly tornadic thunderstorm near Wortham, Texas in Freestone and Navarro Counties west of I-45 and along Highway 14. This storm was an HP supercell storm, and its main core, containing at least golfball-sized hail, was indirectly penetrated. Winds gusting near 60-MPH, heavy rains, frequent lightning, and hail to quarter sized (about 1") was encountered. A large rotating wall cloud was observed on the inflow side of the storm with an RFD / rain hook feature as well. The storm was caused by the interaction of an outflow boundary and stalled cold front, surface heating, and an upper trough. Documentation was HD video and digital stills. A 2009 Kia Optima was used to chase the storms. A tornado watch was also valid for the area until 9 PM CDT.

4). May 22, 6:00 PM - Observation and indirect penetration of an extremely severe and violent tornadic thunderstorm in Edmunds County, South Dakota from near Lowry and through Bowdle and to just west of Aberdeen along Highway 12 and points north. This storm was a violent cyclic supercell, starting out as a classic supercell, then evolving to HP during its later stages. At LEAST six tornadoes were produced and observed with this storm, all of them significant. One possibly violent tornado was observed near Bowdle, causing significant damage (if not - total devastation) of some farmsteads north of the town. Transmission powerlines and a radio tower were also destroyed. This tornado was a mile-wide wedge tornado, and was observed from close proximity, with inflow / RFD winds approaching 100 MPH (or more). The storm also acquired the "stacked plates" structure during its early HP stages, with the appearance of an "upside-down wedding cake" at times, with a tornado still on the ground. The backside of the storms core was observed, with winds well over 75-MPH, baseball sized hail, lightning, and torrential rains were encountered (I had to seek shelter behind a farmer's shed). The other tornadoes produced by this storm were cones and stove-pipe type tornadoes. The storm was caused by the interaction of a warm front / boundary, dryline / confluence axis, surface heating, low-pressure area, and an upper trough. Documentation was HD video and digital stills. A 2009 Kia Optima was used to chase the storms. A tornado watch was also valid for the area until 1 AM CDT (the following day).

5). May 23, 5:30 PM - Observation and penetration of a severe thunderstorm south of Oberlin, Kansas in Decatur County along Highway 83. The storm was part of a multicell cluster of strong and severe thunderstorms, and was penetrated in order to reach other more severe storms / supercells to the south. The largest hail associated with this storm was observed to the east of the chase track, with an impressive hail-shaft visible. Conditions observed were 60 to 70 MPH winds, hail up to 1", frequent lightning, and torrential rains. Conditions causing the storms were moisture convergence, a developing low pressure area, dryline to the west and warm-front to the north, surface heating, and an upper trough. Documentation was digital stills and HD video. A 2009 Kia Optima was used to chase the storms. A tornado watch was also valid for the area until 12 AM CDT the following day.

6). May 23, 7:30 PM - Observation of a very severe and tornadic thunderstorm north of Oakley, Kansas from Highway 83 in Thomas County. The storm was an HP supercell storm, and its core was allowed to pass to the west. A large truncated cone tornado was noted on the rain-free base of the storm, which evolved to a smaller tornado before lifting in about 5 minutes. The tornado was observed at a distance of at least 10 miles, but well visible and a report was called in for it to the NWS. The storm core contained hail to about 2" (not penetrated) and frequent lightning was observed as well. Conditions causing the storms were moisture convergence, a developing low pressure area, dryline to the west and warm-front to the north, surface heating, and an upper trough. Documentation was digital stills and HD video. A 2009 Kia Optima was used to chase the storms. A tornado watch was also valid for the area until 12 AM CDT the following day.

7). May 23, 9:00 PM - Observation of an extremely severe and tornadic thunderstorm from southwest of Atwood, Kansas and along Highway 36 in Rawlins County to near Bird City. The storm was another HP supercell storm, also observed from a distance, and two tornadoes were observed in the darkness (illuminated by lightning) from a distance (10 miles or so). One was briefly visible southwest of Atwood and another north of Bird City. The core was avoided but probably contained very large hail. The storm also had an impressive "barber pole" updraft when viewed from the south near Bird City. The storm also was producing nearly continuous lightning (CC and CG). Conditions causing the storms were moisture convergence, a developing low pressure area, dryline to the west and warm-front to the north, surface heating, and an upper trough. Documentation was digital stills and HD video. A 2009 Kia Optima was used to chase the storms. A tornado watch was also valid for the area until 12 AM CDT the following day.

8). May 24, 4:00 PM - Observation and penetration of a very severe thunderstorm along Highway 385 and north of Hemingford, Nebraska in Box Butte County. The storm was an intense cell embedded in a multicell line of storms. Hail to nickel-sized, torrential rains, frequent lightning, and winds gusting over 80-MPH were encountered with this storm. Tree damage was also observed with this storm. Conditions causing the storms were a strong cold front, low pressure area, surface heating, and an upper level low pressure area. Documentation was digital stills and HD video. A 2009 Kia Optima was used to chase the storms. A tornado watch was also valid for the area until 8 PM MDT.

9). May 24, 6:30 PM - Observation and penetration of another very severe thunderstorm from south of Hay Springs near Highway 87 in Box Butte County, Nebraska and eventually north and eastward along Highways 391 and 18 into South Dakota and to as far as Mission, South Dakota. The storm was a multicell line of severe thunderstorms, in which en embedded HP supercell storm was observed early on before evolution to a derecho-like outflow dominant MCS. Hail, torrential rains, lightning, and winds gusting to near 90-MPH were observed with these storms. The strong winds kicked up a lot of dust, and pebbles were blown into my chase vehicle at one point. Some tree and sign damage was also noted. Conditions causing the storms were a strong cold front, low pressure area, surface heating, and an upper level low pressure area. Documentation was digital stills and HD video. A 2009 Kia Optima was used to chase the storms. A tornado watch was also valid for the area until 8 PM MDT.

10). May 25, 4:30 PM - Observation of a severe thunderstorm just west of Johnson City, Kansas and into Colorado just west of the border along Highways 160 / 89. This was in Baca County in Colorado and Stanton County in Kansas. The storm was a small supercell storm which produced a wall cloud and funnel during its high-point. The storm also contained large hail, gusty winds, and very heavy rains. The core was not directly penetrated, so only small hail was observed. Conditions causing the storms were a stationary front / outflow boundary, approaching dryline, surface heating, and an upper trough. Documentation was digital stills and HD video. A 2009 Kia Optima was used to chase the storms. A severe thunderstorm watch was also valid for the area until 10 PM CDT.

11). May 25, 6:30 PM - Observation and penetration of an extremely severe and tornadic thunderstorm from just west of Towner, Colorado in Kiowa County and into Kansas near Tribune and as far as Scott City in Scott County. This cyclic supercell storm was observed from near Highway 96 in Towner and Tribune and also along county roads north of Highway 96. In Sheridan Lake County, Colorado, the developing supercell storm produced at LEAST five land-spout type tornadoes. The storm became a very powerful cyclic supercell storm, and had a large rotating wall cloud when it was west of Towner. Hail at least 2" was also observed north of Highway 96, which completely covered the ground in some places. The storm split, and the main portion continued eastward near Tribune, Kansas, where two more tornadoes were observed. More large hail and high winds were encountered north of Scott City hear Highways 96 and 83. Largest hail observed falling was up to 2" (half dollar sized). The storm also contained frequent lightning and strong winds (near 65-MPH). Hail fog was observed with the hail falls that covered the ground. The storm also produced some spectacular wall clouds, one of them touching the ground! Conditions causing the storms were a stationary front / outflow boundary, approaching dryline (with a triple-point to the stationary boundary), surface heating, and an upper trough. Documentation was digital stills and HD video. A 2009 Kia Optima was used to chase the storms. A severe thunderstorm watch was also valid for the area until 10 PM CDT.

12). May 26, 5:00 PM - Observation and indirect penetration of an extremely severe, and possibly tornadic thunderstorm in Weld / Morgan Counties in northeastern Colorado from south of Interstate 76 near Bennett and east to near Wiggins and Highway 52. The storm was an LP and / or classic supercell thunderstorm. The storm core was not directly penetrated, yet hail up to 2" was observed falling on the edge of the storm core, with an impressive RFD. A brief weak tornado was also observed with the storm near Prospect Valley. The storm had also had the impressive "stacked plates" and striations on the updraft, with a very striking visual appearance during its intense stages. Conditions causing the storm were surface heating, upslope wind flow (lee trough), and an upper trough. Documentation was digital stills and HD video. A 2009 Kia Optima was used to chase the storms. A tornado watch was also valid for the area until 8 PM MDT.

13). May 29, 7:00 PM - Observation and indirect penetration of severe thunderstorms near Highway 2 from near Hyannis to Thedford, Nebraska in Grant and Hooker counties. The severe storms were part of a multicell cluster of storms. The core of the most intense storm was not directly penetrated (contained hail to near 2"), but frequent lightning, heavy rains, 60-MPH winds, and hail to 1" was encountered. The storms began as a multicell cluster of storms (with embedded HP supercells), but quickly became outflow dominant. A funnel was observed on the southern side of the storm to the NE of Whitman, Nebraska. Conditions causing the storms were surface heating, a cold front, weak low pressure area, and an upper trough. Documentation was digital stills and HD video. A 2009 Kia Optima was used to chase the storms. A severe thunderstorm watch was also valid for the area until 11 PM CDT.

14). May 30, 6:00 PM - Observation and indirect penetration of a very severe thunderstorm from north of Nash, Oklahoma in Grant County and southeast into Garfield County near Kremlin near and along Highways 11, 64, and 81. The storm began as a supercell storm (classic) with a wall cloud, then transitioned to an outflow dominant multicell storm cluster of severe thunderstorms. Winds associated with these storms gusted over 70-MPH, with torrential rains, frequent lightning (with some close hits), and hail up to 3/4 inches. The storm core of the supercell was not directly penetrated, and contained hail to golfball (1.75") in size. Some tree damage was also observed with this storm. Conditions causing the storms were surface heating, a slow-moving cold front, low pressure area, upper trough, and dryline / shear axis. Documentation was digital stills and HD video. A 2009 Kia Optima was used to chase the storms. A severe thunderstorm watch was also valid for the area until 12 AM CDT the following day.

15). May 30, 8:30 PM - Observation and indirect penetration of another very severe thunderstorm west of Crescent City, Oklahoma in Logan and Kingfisher Counties near Highway 33. The storm was a supercell storm (classic) with a rotating wall cloud with some brief funnels, and was the "tail-end Charley" southernmost storm in the multicell storm complex (MCS) farther north. The storm core of the supercell was not directly penetrated, but hail to about 1.25" was observed, along with heavy rains, 40-MPH winds, and frequent lightning (with numerous close hits). The main core had hail to tennis-ball sized, and the hail roar / clanking could be heard on the rear-flank of the storm. Conditions causing the storm was surface heating, a slow-moving cold front, low pressure area, upper trough, and dryline / shear axis. Documentation was digital stills and HD video. A 2009 Kia Optima was used to chase the storms. A severe thunderstorm watch was also valid for the area until 12 AM CDT the following day.

This concludes the Chase Log for the US Great Plains and Midwest storm chasing trip from May 18 through June 1, 2010. This chase summary includes a total of 15 severe storm interceptions and / or observations. Out of these observations, a total of at least 20 tornadoes / large funnels were observed. The main chase vehicle conducting all chases is a 2009 Kia Optima (rental). This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.

GALLERY FOR MAY 18 TO JUNE 1, 2010

Above is a terrifying view of the violent tornado, rated high-end EF-4, just about to cross north of the small town of Bowdle, South Dakota on May 22, 2010. There is a farmstead in the foreground and it is just about to be hit by the southern edge of the tornado, nearly a mile wide at times. Tornadoes that are wider than they are tall, like this one, are called "wedge" tornadoes. Such tornadoes have a very complicated damage pattern, as there is one large circulation, with smaller circulations inside.

GALLERY FOR MAY 18, 2010

Severe Thunderstorm over Fort Lauderdale airport ... This caused my flight to be delayed nearly two hours. I watched my plane ALMOST land, then fly back out (abort the landing), and later found out they circled, could not land because of the storm, got low on fuel, and had to divert to another airport to re-fuel. This was the flight that I was supposed to be on. Luckily, I had a continuing service connection (no plane change) in New Orleans, so I simply got into Dallas late.

GALLERY FOR MAY 19, 2010

Convective initiation to the northwest of Clinton, Oklahoma as anxious storm chasers watch.
Rapidly developing supercell storm to the northwest of Leedey, Oklahoma over Roger Mills county.
Tornado to the northwest of Leedey, Oklahoma from the rapidly intensifying supercell. The view is west and northwest.
Another possible tornado / rotating wall cloud viewed from west of Eagle City, Oklahoma. The view is to the east.
Rapidly rotating / rain wrapped tornado near Kingfisher, Oklahoma. Visually, this was basically tagging scud really close to the ground.
The "chaser convergence" with this storm was insane ... Literally traffic jams of chasers and equipment, including the VORTEX II scientists!
Violently rotating wall cloud over Guthrie, Oklahoma before the storm moved east and weakened.

GALLERY FOR MAY 20, 2010

This is a view looking south at the MCS / thunderstorm line from extreme southeastern Oklahoma. The "area of interest" will be at the extreme southwest portion of this line of thunderstorms, to the lower-right in the picture (in NE Texas).
Forward-flank gust front and shelf cloud on the eastern side of an HP supercell near Fairfield Lake, Texas.
Interesting bowl shaped and rotating wall cloud on the inflow side of the HP supercell storm near Fairfield Lake.
Another HP supercell storm west if Interstate 45 (near Wartham, Texas). The view is to the west and northwest.
Rotating wall cloud in the supercell "bear's cage" near Wortham, Texas looking northward and with the rain "hook" behind me.
Beautiful mammatus seen from north of the line of supercells on the storm anvil at sunset near Corsicana, Texas.

GALLERY FOR MAY 21, 2010

Here is a "storm chaser's worst nightmare" ... Waiting for the pilot car in a suprise long construction delay along Highway 385 in Northeastern Colorado north of Burlington. Not something any chaser rushing to a storm 100+ miles away wants to see. This delay pretty much tanked the chase for May 21.
Here is a view of the tornadic supercell in far east-central Wyoming / western Nebraska from at least 100 miles away in SW Nebraska.

GALLERY FOR MAY 22, 2010

Convective initiation northeast of Pierre, South Dakota near the intersections of Highways 83 and 14. We watched this develop from blue sky just an hour prior. Believe it or not, this innocent looking cloud will be a violent supercell in about an hour, producing multiple tornadoes.
Here is a picture of the developing supercell southwest of Lowdy, South Dakota during its early stages.
The same storm develops an impressive and rapidly rotating wall cloud.
Developing and rapidly intensifying tornado to the west of Bowdle and southeast of Java near Highway 12.
Multi-vortex tornado evolving to a violent stovepipe south of Highway 12 and west of Bowdle.
Possible satellite / old meso (or left split) tornado to my northwest just as the main (intensifying) tornado is about to cross Highway 12 to my east.
Developing wedge tornado crossing Highway 12 west of Bowdle. The "Dominator" vehicle (Reed Timmer) is INSIDE this tornado as I was taking this picture!
Tim Samaras's main vehicle (with TWISTEX) to the left side of Highway 12 (looking east) and a new in-situ tornado instrument (trailing red marker smoke) that measures tornado winds at 0.7m and 2m to the right. The tornado is just to my north and out of frame to the left.
Multi-vortex stage of the tornado just to my north (on Highway 12) and west of Bowdle, SD.
This has to be one of the most impressive RFD (Rear Flank Downdraft) clear-slots I have ever seen! The violent wedge tornado is to the far right. You can actually see blue sky and crepescular rays of sunlight through the RFD cleat slot.
Fully developed and violent wedge tornado just north of Bowdle, SD. The farmstead in the forground sustained serious damage.
The arrow in this picture points to a pickup truck with its headlights on ... This was a resident of the farmstead, with his family and his dog, fleeing for their lives and escaping certain death. I spoke to these folks a day later and they said "We had a choice: Cellar or leave - We chose 'leave'!"
Some flying debris, actually parts of a roof, clearly airborne in this close-up shot of the wedge tornado's southern edge north of Bowdle.
Power flash as the wedge tornado reaches and destroys ultra-high voltage transmission lines.
Tornado crossing the farm road north of Bowdle as other chasers watch in awe.
The violent supercell storm cycles again and the new mesocyclone produces another cone tornado (evolved to a stove-pipe) east of Bowdle as viewed from Highway 12 (the view is northeast).
Absolutely INSANE supercell structure north of Ipswitch with a weakening tornado to the extreme lower left of the picture.

GALLERY FOR MAY 23, 2010

This is a picture of some of the damage to a farmstead (totally destroyed) north of Bowdle, South Dakota a day after the tornado hit. We had to be escorted by the local sheriff and had permission from the owners to take these pictures. Myself and the TWISTEX chase group were conducting the damage survey in the morning before leaving South Dakota for a target area in NW Kansas.
Here is the anvil of a cluster of severe thunderstorms looking south from Highway 83 near the Kansas / Nebraska border. These storms began as multicell, but evolved to supercells once upper level support / low-level dynamics arrived.
Here is a truncated cone tornado viewed from north of Oakley, Kansas and west of Highway 83. This tornado was spawned by an HP supercell storm that was a left split from a seemingly more intense southern (right) split. Myself and chaser Dan Shaw were some of the only chasers who saw this, and we reported it to the NWS.
Here is another view of the tornado west of Highway 83 by about 10 miles and north of Oakley, Kansas just before lifting.
Another HP supercell, also tornadic, produced large amounts of lightning to the southwest of Atwood, Kansas after dark.

GALLERY FOR MAY 24, 2010

This is a view west towards what appeared to be a developing supercell storm, but was the start of a line of thunderstorms. The view is to the west from the Nebraska / South Dakota border and south of the Pine Ridge Indian resrvation.
Here is a picture of the backside and hail shaft (with an interesting funnel shaped silhouette in the center of the picture) from a supercell storm embedded in a developing squall line near Alliance, Nebraska.
Once the storms in NW Nebraska evolved into a powerful squall line, outflow winds gusted over 80 MPH in some places, raising dust as in this picture.
Here is a downed tree after the squall line passed through Valentine, Nebraska.
Incredible display of mammatus clouds over Valentine, Nebraska an hour or so after passage of the squall line.

GALLERY FOR MAY 25, 2010

Here is a view of a developing supercell storm in Sheridan Lake County, Colorado. The storm is developing on the intersection of the dryline (left) and a stationary boundary (left to right) called a "triple point". Look very closely to the lower left and you can see one of the first land-spout type tornadoes I observed with this storm!
Here is a picture of the second land-spout type tornado I observed with this supercell in Sheridan Lake County. This tornado developed a bit closer to the supercell than the one pictured above.
Yet another large land-spout tornado develops in Sheridan Lake County. This is tornado number three for me, and this one has a expansive dust cloud at its base.
These are two land-spouts ocurring simultaneously, and "dancing" around each other. They were roughly a half mile apart, and ocurred just before land-spout in the picture above lifted (to the right and out of this picture) - This makes my tornado count for this storm four and five!
The supercell storm in Sheridan Lake County, Colorado had a wall cloud literally scraping the ground!
Here is a picture of the hail-fall northwest of Towner, Colorado. The ground is completely covered with hail ranging from marble sized to half-dollar. Note the eerie hail fog hanging in the air. This storm dropped the temperature from 85 degrees to 45 in about 5 minutes!
Nice piece of golf-ball sized hail. This was probably more like 2" as it has melted quite a bit.
Another tornado develops from the supercell right-split north of Tribune, Kansas. This is the sixth tornado I observed from this storm.
Beautiful narrow tornado develops between Selkirk and Leoti, Kansas. This is tornado number seven from this supercell I observed.
This is a picture of one of the storm chasing tour groups watching the supercell rain-free base and wall cloud.
Here is a picture of an approaching hail core (with green hue) north of Scott City, Kansas and along Highway 83. The view is to the southwest just before getting slammed with golf-ball sized hail.

GALLERY FOR MAY 26, 2010

Here is a view of the developing supercell storm from about 25 miles to the northeast on I-76 (looking southwest). This storm initiated off the Palmer Divide (NE of Denver) and began moving northeast.
Rapidly rotating wall cloud north of Bennett, Colorado.
I think this was a weak tornado that breifly formed, resembling rotating scud. This was northwest of Prospect Valley, Colorado and not far from Bennett.
This supercell produced hail over 2 inches, with smaller marble sized hail covering the road as seen here. My vehicle had dents from this very hard hail (I saw golfball sized), and it cracked the driver's side mirror.
View of RFD clear slot directly overhead from the edge of the hail core of the intensifying supercell near Prospect Valley, Colorado.
Incredible storm structure of the LP / Classic supercell when it was exiting Weld County and entering Morgan County, Colorado.
Some of the V2 (VORTEX II) personnel with a DOW (Doppler On Wheels) type truck scanning the supercell storm south of Wiggins, Colorado.
One of the National Severe Storms Laboratory research vehicles with another distant supercell storm in the background.
This is a view back towards the weakening supercell storm with a high base and RFD slot still visible to the left.
This rather long chase day ended with a stay in Denver, Colorado for the night. Here is the Denver Skyline with a distant supercell thunderstorm (Near Pueblo) looming in the distance.

GALLERY FOR MAY 27, 2010

My first, and well deserved "off day" for this trip was spent at Pikes Peak. This peak is over 14,100 feet above sea level. Conditions at the mointain base were light winds out of the SE and 90 degrees. At the summit, temperatures ranged from 30 to 45 degrees, with a stiff SW wind gusting over 50 MPH (72 MPH early in that morning). Weather was crystal clear with high base clouds, allowing a view spanning hundreds of miles.

GALLERY FOR MAY 28, 2010

Here is the view looking south from along Highway 20 near the Nebraska / Wyoming border during the off / reposition day of May 28. Wide open spaces - The wild west!

GALLERY FOR MAY 29, 2010

This is a picture of the Dominator (similar to Sean Casey's tornado intercept vehicle), but designed and operated by the Tornado Videos (TVN) network. Designer and meteorologist Reed Timmer is standing in the blue shirt. Note the air cannon package, which is designed to launch parachite-borne instruments into a tornado / supercell updraft.
These are the "probe" vehicles, each with a mobile mesonet (weather instrumentation), preparing for a chase in Hyannis, Nebraska. These vehicles are part of the VORTEX II project, operated by the NSSL (National Severe Storms Laboratory).
A severe thunderstorm develops ahead of the approaching cold front to the east of Hyannis, Nebraska and briefly acquires HP supercell characteristics before being undercut by the outflow.
The severe thunderstorm east of Hyannis and near Whitford, Nebraska produced this funnel cloud and weak RFD as viewed from Highway 2. The view is to the north.
Here is one of the DOW (doppler on wheels) radar trucks operated by the NSSL for the VORTEX II project as a severe thunderstorm approaches. Storm chase Jim Reed is standing on the SUV in the yellow rain jacket taking pictures.

GALLERY FOR MAY 30, 2010

Todays target was in north-central Oklahoma near the intersection of a wind-shift line ands a stalled cold front, and the soouthernmost cells in a squall line stretching into Kansas were the storms of interest. In this picture, an intense cell fires north of Vance Air Force Base, Oklahoma.
The severe thunderstorm cell north of Vance Air Force Base briefly becomes a supercell storm, producing a wall cloud, before being under-cut by the outflow / slow-moving cold front.
This is a picture looking up at a weak forward-flank mesocyclone as the supercell storm evolves to a multicell line near Nash, Oklahoma.
This is the wall cloud associated with another supercell storm on the southern-most portion of the line / cluster of severe thunderstorms near Crescent City, Oklahoma. These storms are called the "tail-end Charley" supercells.
Another view of the wall cloud associated with the supercell west of Crescent City, Oklahoma with amazing lightning.
Funnel cloud and another CG lightning strike west of Crescent City, Oklahoma.

GALLERY FOR MAY 31, 2010

This was the last full day available for chasing, but the storms developed too far away in order to make the target and / or make it back in time for my return trip the following day. The yellow "X" is near Woodward, Oklahoma, and that's the closest I was able to get to the storms without driving without sleep and / or missing my flight out of Dallas, TX on June 1. These storms produced MULTIPLE tornadoes in SE Colorado.

GALLERY FOR JUNE 1, 2010

Here is a picture of some flashes of lightning from a distant thunderstorm over the Gulf Of Mexico while en-route from Houston, Texas to Fort Lauderdale, Florida on the return-flight at the end of my trip.

RADAR ANALYSIS OF THE MAY 22 (BOWDLE, SD) STORM

This section highlights an interesting analysis done on the violent supercell (nearing its maximum intensity) that affected Edmunds County, SD on May 22, 2010. The analysis was done using Gibson Ridge's "GRLevel2 Analyst" software, which allows a data set of radar imagery (in this case from the NWS Doppler radar site archives for Aberdeen, SD) to be disseminated and analyzed as a three-dimensional model of the storms involved.

In the image above, the supercell storm is nearing maximum intensity, and is producing a violent tornado at that time. It presents an impressive two-dimensional radar image (base reflectivity) and classic "flying eagle" shape, with the intense hook (and tornado) north of Bowdle, SD at that time. The yellow "triangle" symbol is the approximate location of the tornado, and the "intersection" just below that is Highways 12 and 47 through the town of Bowdle, SD itself.

The image above shows the two-dimensional velocity imagery associated with the Bowdle, SD supercell at the same time as the first reflectivity image above. Again, the yellow "triangle" denotes the location of the tornado, as detected by the radar software algorithm. The intense "couplet" near that triangle is a TVS and is denoted by bright red (moving away from Aberdeen's NWS radar site) and bright green (moving towards that site). Aberdeen, SD is roughly 30-40 miles to the east of the supercell's location at this time. Where the intense green and red areas "touch" is called gate-to-gate shear / divergence, and that is indicative of a tornado (tornado vortex signature / TVS).

The image above is one of the three-dimensional rendering of the supercell storm, as well as neighboring storms, with the lightest reflectivity iso-surfaces made semi-transparent. The shape of the storm, including the anvil, can be visualized, and the time-frame of the analysis is the same as the two (base reflectivity and velocity) two-dimensional images above. The virtual view is looking to the northeast from the "rear-flank" side of the storm. The location of Bowdle, SD is roughly above the "O" in the word "SOUTH" in the rendering. The top of the supercell was just under 50,000 feet MSL.

This is an impressive three-dimensional rendering of the supercell at maximum intensity (north of Bowdle, SD) at the time it was producing the EF-4 wedge tornado. This rendering has only the reflectivities below 55 DBz made transparent, allowing the most intense core iso-surfaces to be visualized. The view is looking towards the southwest, and allows an impressive BWER (bounded weak-echo region) to be seen as well as the debris "knob" / RFD precipitation near the tornado extending high into the supercell core. Intense forward flank precipitation can be seen to the right of the BWER and tornado area. The BWER extends to at least 20,000 feet MSL. The actual tornado, based on this graphic, is located on the north (just right) of the intense reflectivity lobe and south of the "clear" BWER on the left side of the rendering.

Looking nearly straight down (and slightly northwest), an interesting "vortex hole" feature can be visualized in this three-dimensional rendering of the supercell north of Bowdle, SD if the iso-surfaces higher than 40 DBz made semi-transparent (but less than that transparent). This is basically the "eye" of the storm mesocyclone, which is so intense, that it creates an area of reduced returns extending all the way to the top of the supercell. Such a feature is observed on only very intense supercells (usually producing violent tornadoes), and was observed in other notable events, including Hallam, NE in May 2004 and Greensburg, KS in May 2007.

Here is a final three-dimensional rendering of the supercell as it was near Ipswitch, SD and still producing tornadoes and entering HP / line-segment mode. All the lower iso-surfaces under 45 DBz) were made nearly-transparent and those above 45 DBz were made semi-transparent. Only the 65 DBz (or higher) iso-surfaces (pink / magenta) were made opaque, and an impressive precipitation core (most likely extremely large hail) is revealed in a large area to the north and west of the mesocyclone. This area of intense reflectivity extends to at least 20,000 feet MSL, with an isolated return above 30,000 feet!

Above is an image (from video) taken from an aircraft (Boeing 757) flying at about 38,000 feet and south of the supercell storms as they were west of Aberdeen, SD on May 22, 2010. This is roughly at the same time the last radar analysis above, and as the storm was transitioning from HP to a line segment. The underside of the anvil is illuminated by one of many intense could-to-cloud lightning flashes and the lights far down to the lower-right are from Aberdeen, SD. The image is courtesy of Stuart Mike (a pilot), and a video of this storm in greater detail can be seen at the link for it at www.flickr.com/photos/31182650@N08.

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