The following entries are all storm chases and interceptions performed in the Midwest United States from a period from May 19, 2000 to May 29, 2000. This log is based on a joint effort of a storm chasing team. There is myself - Chris Collura (Skywarn storm spotter code B036), Jeff Gammons, and David Cornwell for the main chase team from Florida. This is jointly with the Weather Information Network or "Weathervine". The main chase vehicle was a 1996 Chevy Blazer.

The remaining documenting chasers were Jesse Snyder and Michael Neumann from Michigan and Tom Fitzpatrick as an observing apprentice from Illinois. These three were in a 1999 Ford Ranger Pickup and carried extensive camera gear. A third chaser, Amos Magliocco from Denton, Texas, also joined us for several vital chases while providing some important target area suggestions and forecast help. He was in his own 1998 Toyota 4-Runner. April Swimm remained at the home base in West Palm Beach, Florida for updates some administrative work.

Communications employed were HAM radio, CB radio, FRS hand-held radios, and cellular phones and / or modems. Extensive camera and video equipment was also on board along with GPS and a laptop computer for navigation. The main chase duties were shifts in navigation using the GPS, radio communications, driving many miles, and preparing forecast data. More than 6000 miles were logged on this chase, NOT including the drive of the main chase vehicle with Jeff and David from Florida to the Midwest. Other members including myself flew into Dallas, Texas on the first day of the trip. The chasing involved Texas, Arkansas and Oklahoma sometimes in the worst driving conditions imaginable, in very remote regions.

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. The chase log is also augmented with a small chart at the conclusion the log showing types of observations.

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. It is also advised that chasing in the Great Plains is to be done only be experienced people as a group.

1). May 20, 8:30 PM - Direct penetration of a severe thunderstorm in Ellis County, Oklahoma near Highway 283 and Highway 60. While traveling south after photographing lightning and two tornadic supercells (over Kansas) from a 50 mile distance, an outflow boundary fired a multi-cell cluster of severe thunderstorms near our area. One severe cell was penetrated containing frequent lightning with close hits, torrential rains, and winds gusting 65 to 70-MPH. Some tree debris was noted, some of which hit the driver side door of the chase vehicle, causing a dent. Power was also knocked out in a small town in the area. The storms were caused by a low-pressure trough with a slight dry-line bulge coupled with surface heating. A 1996 Chevy Blazer and 1999 Ford Ranger Pickup was used to chase the storms. Documentation was still photos and camcorders.

2). May 21, 7:30 PM - External observation of high based type severe thunderstorms in Motley County, Texas near FM 94 and Highway 70 in the cap rock country southeast of Amarillo. Some moderate to heavy rains and 30 MPH winds were encountered followed by one of the most spectacular lightning displays that lasted well after sunset. The high elevation storms developed along a bulge in the dry-line and an upper level low, which was actually visually revealed by a swirl in the high clouds left over from some small elevated LP supercells. After dark, the storms evolved into a large multi-cell cluster of severe thunderstorms containing golf ball sized hail, which raced eastwards with the dry line punch. A 1996 Chevy Blazer and 1999 Ford Ranger Pickup was used to chase these storms. Documentation was camcorders and still photos of the spectacular lightning from these storms.

3). May 22, 7:00 PM - External observation of a tornadic and very severe thunderstorm moving into Arkansas near Fort Smith in Scott County. The storm began as a classic supercell which evolved into a low-top storm that back-built into a large LP / HP hybrid supercell near the Ozark Mountains, where the chase was aborted due to the poor road network. A large hail shaft and small funnel cloud was observed on the upwind side of the storm. Tennis ball sized hail and damaging winds were reported with this storm, but not intercepted. The Doppler On Wheels trucks, Weather Channel truck, and several other chasers were also converging on this storm. Our chase vehicles were a 1996 Chevy Blazer and a 1999 Ford Ranger Pickup. Documentation was still photos and camcorders. Intense surface heating (3500 CAPE) and a low-pressure trough caused the storms. A tornado watch was also in effect for this area until 8 PM CDT.

4). May 24, 7:30 PM - Direct penetration of an extremely dangerous severe and tornadic thunderstorm in Canadian county, Oklahoma near the town of Bridgeport west of El Reno. The storm was also near Interstate 40 and Highway 270 where an attempted track to go east then southeast of the explosively developing storm was attempted. The core of this HP supercell was punched from the north and had to be aborted because of the severe hailstorm and winds encountered. The storm developed from nothing to 74 DBZ in less than 15 minutes! During the core punch, although not intentional, winds gusted well over 70-MPH and golf ball sized hail fell sideways in zero visibility. Lightning was frequent with some close hits and visibility was zero. Power was knocked out by the storm and tree debris was observed in the road. When aborting the core punch, the chase path continued back to Interstate 40 and refuge was seeked at a Loves truck stop. Here, hail up to quarter sized covered the ground as 60-MPH winds shifted from south to north as the circulation of the storm mesocyclone passed to our south. The tornado was not intercepted. Hail cracked the windshield of the 1999 Ford Ranger Pickup and chipped some paint on the 1996 Chevy Blazer used in this chase. A third chase vehicle, a 1998 Toyota 4-Runner, was not damaged in the chase as refuge was seeked under an overpass. A region of convergence, intense surface heating, a strong low-pressure trough, a 130-MPH jet streak aloft, and a punch in the dry-line caused the storms. Documentation was camcorders. A tornado watch was also in effect for the area until 10 PM CDT.

5). May 25, 8:00 PM - Direct penetration of regions of severe thunderstorms and observation of a tornadic HP supercell storm in Crosby and Dickens counties in Texas near Crosbytown. A well-developed wall cloud was first observed beneath a rotating HP supercell that also had a tornado warning associated with it. Funnel clouds were observed but nothing touched down near us. The storm's hail shaft, greenish-black with softball sized hail that could actually be heard hitting the ground miles away, prompted us to retreat along FM 2794 to the East. The storm cycled a few times with several wall clouds and funnels before evolving into a large multi-cell storm cluster. The east and north sides of the remaining HP storm were penetrated and 75 to 100 MPH outflow winds were observed. This blew tumbleweeds and tree debris all around. Nearly continuous CG lightning was observed with many close hits, one of which started a fire near Spur. Power was knocked out and one building had all its windows blown out by the straight-line winds. The sky at 8:30 was like night with zero visibility, which gave way to ¾ inch hail and a brilliant green as the chase track punched the storm. Some letters of the "Weathervine" logo on the side of the 1996 Chevy Blazer were stripped off. The 1998 Toyota 4-Runner and 1999 Ford Ranger Pickup faired well in this chase. The storm also caused flooding. Documentation was camcorders, still photos, and audiotape. Conditions causing the storms were a deep layer of low level moisture and very high surface heating (CAPE over 5000), a jet stream aloft, and a punch in the dry-line. A tornado watch was in effect in the area until 10 PM CDT.

6). May 25, 11:00 PM - External observation of severe thunderstorms in Stonewall County, Texas, north of Aspermont on Highway 83 near Highway 380. The storm began as a high-based thunderstorm that evolved into a multi-cell cluster of low base storms as outflow boundaries from the initial storm developed. The primary focus on these storms, which contained golf ball sized hail, was lightning photography and video. Analysis of the video revealed a funnel cloud and large wall cloud illuminated by the lightning. Another chaser, Eric N., used mobile radar to pinpoint the storm during a small convergence of chasers. By about 12 AM, the storm evolved into a single HP supercell with baseball sized hail. This cell was not penetrated, neither was a tornado spotted by our team. Chase vehicles were a 1996 Chevy Blazer, 1999 Ford Ranger Pickup, and a 1998 Toyota 4-Runner. A persistant layer of warm low level moisture, a jet stream aloft, and a punch in the dry-line caused the storms.

7). May 26, 7:00 PM - Indirect penetration and observation of an extremely dangerous tornadic supercell in Haskell and Throckmorton counties, Texas near Highway 380. This storm explosively developed in Haskell county and had a rather long track with a tornado observed during its later stages! The first encounter was north of Haskell County, where a well-developed HP supercell was observed with a rotating wall cloud. A second low base, with apparent rotation, developed on the north side of this cell, moved north, and dissipated. This was a splitting storm. The southern cell began back building to the south and reached a classic supercell structure with funnel / wall clouds. Large hail, ½ to ¾ inch, began falling from the storm anvil well away from the main core, with inflow winds up to 50 MPH. To avoid the hail shaft, with grapefruit sized hail, we tracked South to Throckmorton and East on Highway 380. The storm cycled as a right moving HP storm and had a violently rotating wall cloud. A funnel quickly spun up and a debris cloud formed on the ground just a few hundred yards away. About 200 chasers converged on this storm, including the two DOW Doppler On Wheels trucks, jamming the roadway. The tornado did some damage in Haskell and Throckmorton counties. The inflow to the tornado circulation, as well as the storms powerful winds, kicked up large amounts of dust and debris. One car was hit by a flying license plate while others had missing windshields from hail. The storm evolved from a long-track supercell into a multi-cell cluster of severe thunderstorms which raced eastward. Conditions around the storm had hail to ¾ of an inch, wind at least 75-MPH, torrential rains, and frequent lightning with close hits during the indirect penetration. The outcome of this storm could have been much worse. Our chase vehicles were a 1996 Chevy Blazer, 1999 Ford Ranger Pickup, and a 1998 Toyota 4-Runner. A low-pressure system, 100-MPH jet streak aloft, a deep layer of warm and moist low level air (6000+ CAPE), dry-line punch, and winds that veered with increasing altitude caused the storms. Documentation was still photos and camcorders. A tornado watch was also in effect for the area until 10 PM CDT.

8). May 27, 5:00 PM - Direct penetration of a very severe thunderstorm in Wise County, Texas along Highway 380 near the town of Bridgeport. This was yet another tornadic HP supercell. The storm was penetrated from the East side during its late mature or "gust out" stage. Winds gusting over 70-MPH, frequent lightning with close hits, and hail at least ¾ inches was observed. Tree debris was observed blown down in Bridgeport, along with power knocked out and signs down. Tornado warning sirens were also activated for this town. The storm gusted out and a large outflow dominant squall line type storm developed along the gust front. This produced a multi-cell line of strong thunderstorms that moved rapidly eastwards. The tornado for this supercell was not observed by any chasers in the area, but softball sized hail was associated with this storm. A 1999 Ford Ranger Pickup was used to chase the storms. Documentation was a camcorder and still photos. A low-pressure trough, dry-line, weakening jet stream aloft, and high surface moisture and heat (3000 CAPE) caused the storms. A tornado watch was also in effect for the area until 7 PM CDT.

This concludes the Midwestern United States Chase Log. The summary includes a total of 8 severe thunderstorms, several funnel clouds, and a well-documented tornado touchdown. The main chase vehicle conducting and leading the first 7 chases was a 1996 Chevy Blazer. The secondary vehicle was a 1999 Ford Ranger Pickup and was used in all the chases. A third vehicle, a 1998 Toyota 4-Runner, was used as a third vehicle in several of the chases. This information was prepared exclusively for the National Weather service and the team of Skywarn storm spotters.