Chase Log 2004

The Year of the Tornado

Distance Total: 5749 Miles

Last Updated 4/16/2006

(Top) Chase Vehicle, Thom Trimble and John Monteverdi at Thedford, Nebraska, May 22, 2004
(Bottom) Three tornadoes simultaneously, near Oxford Nebraska, May 26, 2004

May 20

Arrival at Denver International Airport

After a quick trip to Denver, with a flight time less than 2 h, we decided to head up Interstate 76 to Fort Morgan. Along the way, we connected by phone with Chuck and Vickie Doswell, and decided to hook up today. By the time we got to Fort Morgan, the best dew points were in southeastern Colorado. So we flew down State Route 71 to Limon. There, it seemed apparent that this day would be a down day...wrong. We decided to drive east to Burlington, near the Kansas border, where we expected higher instability.

Another lesson learned. While the buoyancy over northeastern Colorado was weak, the shear was the best. While we met Chuck and Vickie in Burlington, a thunderstorm moved off the moutains across Greeley, and as it came out into the Plains it became a tornado-warned supercell. And where? Approaching Fort Morgan, the very place we targeted and left. However, colleagues who did chase that storm report that they did not observe tornadoes.

May 21

Into North-central Nebraska

We spent the night in Burlington Colorado, and awoke to a developing mesolow in sw Nebraska. On the northeast side of the low, high dew points and CAPE were expected underneath favorable shear for supercells.

We decided to taget the area near Thedford. Unfortunately, things did not pan out as we and the models and SPC expected. As soon as we were driving north of North Platte, the southeasterly winds died. Storms coming out of the Nebraska Panhandle did become severe, but rapidly dissipated as they approached us. Here is a picture of a dying updraft with mammatus formation.

Well, we are holed up in Thedford tongiht, and think we will be in SE Nebraska tomorrow.

May 22

Tornado Outbreak in Nebraska: Furnas County Supercell Tornadoes

What a tremendous day for us. The morning surface map painted an ominous picture for south-central and southeastern Nebraska. All along the Kansas border, easterly or southeasterly flow of 15 knots or more was underrunning strong southwesterly winds in the mid and upper troposphere. SPC had initially had a Moderate Risk for the area, but eventually upgraded the risk to High. SBCAPE values of 3500 J/kg or more and vertical shear values on the upper end suggested the formation of tornadic supercells over the region.

We started out in Thedford, Nebraska with colleague Chuck Doswell and his wife Vickie. Our initial destination was Kearney, Nebraska, where we went into the library and checked the latest data. The best axis of moisture/CAPE was due south near Minden to the Kansas border. We drove southward and then eastward to Minden. There, we saw the anvil of the storm that had developed northeast of Goodland KS. Yet, it was very close, and about to ingest the high CAPE air to our west.

So we moved southwestward. While we did, we heard of tornado waarnings in western Furnas County. As we moved toward Oxford, we saw the ominous loweirng to our southwest. After passing through Oxford, the brief interval allowed an elephant trunk tornado to develop. Screeching to a halt, we rushed to setup our cameras, while the tornado developed into a massive stovepipe. This impressive tornado became a very large barrel, and twisted around about 4 miles from us to our southwest. It eventually roped out.

This tornado then dissipated as the supercell cycled. Near Alma, a second tornado formed, barely visible as we drove eastward, and we only have these two views.

We stayed with this storm as it cycled into another poorly lit and rain-wrapped tornado about 5 miles further east. After this third tornado, we followed the storm as it traversed south-central Nebraska, often getting spectular views of mammatus.

We could see the supercell to the east, that had similar tornadoes. Unfortunately these tornadoes moved through populated areas, and produced a fataility.

May 23

Down Day in Lincoln

After yesterday's exhausting, but rewarding day, we decided to skip traveling to an area with possible supercells, southern South Dakota. May 24 looks to be another big day in southeastern Nebraska for severe storm researchers, so we decided to put down, relax and go to a movie. Unfortunately, that movie was "Van Helsing"...what an awful flick. A colleague of mine, Matt Crowther, participated in the storm survey for Hallum, Nebraska. That unfortunate town was nearly wiped off the map. Matt estimates the damage path as nearly 1 1/3 miles wide.

May 24

Spectacular Cyclic Tornadic Supercells: 12 Tornadoes from 2 Storms

What to do, where to go?

Here I am in the library at Beatrice, Nebraska. The picture painted by the pattern Monday morning was ominous. First, the area of southeastern Nebraska and northeastern Kansas was a focus of strong easterly and southeasterly flow bringing a very buoyant air mass into the area. At the same time, the shear was offscale for supercells, and supercell tornadoes, with low level shear values some of the highest that I have ever seen..SPC had a a High Risk, and included a high probability of strong and violent tornadoes.

At Beatrice, we ran into the Doppler on Wheels armada, which is being trailed by the bozo who is trying to insert himself into a tornado with this ludicrous vehicle. We evaluated the data, and set as our target the area around Beatrice and slightly west and south. By 1 PM we were wondering if our decision was correct. But by 1:30PM cumulus towers could be seen developing slowly around Hastings, about 75 miles northwest of us. Suddenly, around 1:45PM the southern most cell exploded, quadrupling its size in 5 minutes. We were out the door, driving westbound on Highway 4 towards Hebron.

Hebron Supercell

There was already a tornado warned storm north of Hebron, but the parent storm was rain wrapped. So we dropped south to the next storm, which was near the Kansas border. As approached the bell shaped lowering, we all felt that we were about to witness a tremendous show. In fact, as we drove towards it, we saw a weak tornado on the north flank of the wall cloud. That dissapated, and another weaker tornado formed towards the south portion of the wall cloud.

Two and Three Tornadoes Simultaneously! We drove west from Hebron, and the first barrel tornado formed. (The vehicle in the picture is the Doswells'). This became a major cone tornado that became a large stovepipe. This tornado cycled and became an elephant trunk, with a fat another tornado formed to the south of it. This cycled as well, as the northern tornado became dust-filled. Stunningly, a third tornado formed south of the first two, first as a weak dust cone, then as a rope. The largest tornado eventually became a huge stove pipe, filled with dust. Another tornado (not filmed) could be seen, rain-wrapped to the northwest of this funnel. We counted a total of seven tornadoes with the Hebron supercell.

Belleville Supercell

Two or Three Tornadoes Simultaneously? As the Hebron supercell seemed to reach its last cycle, we noticed a new storm to its south. That storm already had a tornado visible south of the forward flank rain area. As we drove south to Belleville, KS, an elephant trunk tornado begain to develop just 1/2 mile north of us, as the civil defense sirens blared in town. We thought that this was the only tornado at the time. But in this shot, you can see another tornado on the occluded part of the mesocyclone northwest of the tornado in the foreground, and a dissipating funnel, nearly horizonal, in the middle of the picture. This storm suddenly had become yet another multiple tornado producer!

We followed this storm east southeast as it weakened, but produced another sinuous rope funnel. We did not see any debris at ground level, but are confident that there was a circulation on the ground. So the Belleville supercell produced at least three tornadoes, one possible tornado, and another dissipating funnel.

Topeka Supercells

We didn't have enough. As the Belleville supercell weakened, we noticed towers going up on the dry line to our east. These spectacular explosions were occurring in the true high CAPE air....5000 J/kg. First the northern most cell became supercelluar, with classic "knuckes" on the back sheared anvil to our east. Then the southern most storm became a cyclic tornado producer, with updrafts being ingested into the main updraft visible as cumulus towers appearing to march like soldiers into the main updraft area. We arrived to late to see the tornadoes, but got a great view of the storms as they developed.

What a day! This astounding set of supercells produced so many tornadoes, it was difficult to keep up with the photography and chasing. We doubt that we will ever see such a productive three day period: 15 tornadoes.

May 25

Plunging South

We spend the night in Emporia KS. The morning surface analysis suggested that the southern tier of counties in Oklahoma might have the proper balance of CAPE and shear for tornadic supercells. But the CIN was too much to overcome. This was our first non-storm day in 5 days. We spent the night in Wichita Falls, TX.

May 26

LP Supercell in North-central Oklahoma

The morning data promised storms in Oklahoma, with a mesolow in southwest Oklahoma, bringing southeasterly flow, rich with moisture, into Oklahoma. The environment was strongly sheared under southwesterly flow aloft. So tornadoes were possible.

We drove north to Altus, and then to Clinton, as a small thunderstorm began to develop strongly. By the time we got near Interstate 40 the storm had a severe thunderstorm warning on it. As we stair-stepped around to the southwest flank of the storm, we saw a wall cloud, that developed a bulbous lowering. At that time, a tornado warning was issued for a location we had in clear view. This was a Doppler -based warning...but there was no tornado. The storm had a good look, though, with awesome mesocyclonic structure. The storm had a merry-go-round look but rapidly weakened. Our last look at it was as drove north to oiur overnight location, Edmond, OK. From that vantage point, the weakening, but still rotating, updraft was still producing excellent structure.

May 27 and May 28

Diddling Around Texas...and back to Kansas, Awaiting Major Severe Weather Episode

On May 27 and 28, we dropped south into north Texas, briefly, since CAPE and shear seemed within ranges for supercells, but most of the area exploded in weak to strong storms. There were a few discrete supercells early, but by the time we got north of Abilene, the entire area was rain covered. So we moved north to Wichita Falls, and then, on May 29, to Concordia KS in anticipation of the probably High Risk of tornadic storms on Saturaday, May 30, Thom's last day for this trip.

May 29

Third High Risk Day--Wedge Tornado

Three tornadoes, but a day of tactical mistakes

May 29 promised to be another active day in the southern Great Plains. SPC had a High Risk ConvectiveOutlook by early morning. Further, they had outlooked a high risk of strong and violent tornadoes in the area. The morning surface plot told the tale. Rich moisture was circulating in southeasterly winds across eastern Kansas into north central Kansas. CAPE values were expected to be around 4000 J/kg by late afternoon under adequate shear for supercells and supercell tornadoes.

We rejoined Chuck and Vickie in Salina. Northeast of Russel (about 65 miles west) towers were already developing. Our first mistake was to go west...the next road was 29 miles west on Interstate 70. That would have been fine if the supercells had true eastward motion, as we expected. Instead, initial storm motions were northeastward. As we drove west, the storms were already approaching the latitude of Concordia, nearly 50 miles to the north. So, we played catch up, arriving under the flank to see the first attempt at a tornado. At that time, the storm was a classic suipercell, with pronounced hook.

But the major tornado occcurred nearly 1/2 hour later, after the storm continued to move northeastward. Our only road option was to go back east, letting the storm outdistance us to the north again. In fact, because of this, although we saw the next three tornadoes, they were viewed from the south...very poor contrast. During this time the storm was morphing into an HP supercell. It had a classic rotating wedding cake appearance. In this shot, looking towards the west, the action area is the huge dark area to the right. In that region was the wedge tornado...which we viewed from a cemetery on Route 28 near Concordia. However, the contrast was so poor, it was impossible to judge if what we were looking at was a huge rain shaft, or a giant tornado, It turned out to be a 1/2 mile wide tornado, that later was rated F2.

We borrowed, with permission, several of the pictures shot by Matt Crowther, whose location was about 10 miles east and north of us. He had a good view of the wedge tornado, nearly 1/2 mile wide, and several of the subsidiary tornadoes. Note the structure of the storm when it was producing the wedge. The vertical shear had a weakness in lower-mid levels. This allowed the storm to spin more of the precipitation around the mesocyclone, making the hook gigantic, and nearly surrounding it. At that time it would have only been possible to view the tornado through the narrow slot on its northeast flank. Clearly, we were out of position to view that. And, in fact, such an HP storm is very dangerous, because visibility is very poor in all areas, even in the usual southeast flank of the storm. The huge mesocyclone actually had 100 mph surrounding it at the ground...clearly enough to do damage, and F0 in damage strength themselves.

We attempted to go north several times, but were stopped by the large hail coming around the south side of the mesocyclone. Chaser Sam Barricklow, who was well to the northeast of the storm, kindly allowed us to include his video (1.7 MB; Quicktime required). While we watched the storm, now out of far reach, we were treated to a display of mammatus, while southeasterly winds of 30-50 mph were sucked into the updraft.

May 30, 31 and June 1


Thom left from Omaha airport on May 30. I decided not to chase the High Risk into Missouri. Thank goodness, since those that did saw little, unless they got to the best shear area, which was in Indiana. I spent the night in Kansas City.

May 31 was spend driving the 600 miles back to Denver, where I spent that night, and June 1, in preparation for my southward trek into the southern Texas Panhandle or the Red River area for June 2.

June 2

Weak Bulk Shear, Moderate Cape:

Joined for two days by Scott Landolt and Rich Bateman, we drifted south to the northeast New Mexico and northern Texas Panhandle. There, an air mass relatively rich in moisture existed in a moderately favorable shear environment under northwesterly flow. The turning of the wind with height from southeasterly at the surface to northwesterly aloft actually gave us around 45 knots of 0-6 km shear. On the morning surface plot, I noted three surface boundaries of significance, a dry line on the west, a west-to-east quasistationary front in the Oklahoma panhandle, and a north-south outflow boundary in the eastern Panhandle. The portion of the Texas Panhandle east of the dry line had significant CAPE. Thus, there was a reasonable chance that, once initiated, storms would rotate, and produce brief, weak tornadoes if and when they crossed the north-south boundary.

The issuance of a PDS Tornado Watch for the Panhandle of Texas perplexed us....we saw nothing in the data (nor do I now) that justified such an elevated level of risk advisory.

In fact, the storms that developed, while having supercellular characteristics briefly (this shows the rotating rainfree base of a storm near Dumas, TX, view towards the northwest) quickly exploded into a Mesoscale Convective System, that roared southeastward towards Childress and Wichita Falls. We gave up early, and spent the overnight in Guymon OK.

June 3

Weak Bulk Shear, Less CAPE, NE Colorado

June 3 promised to draw us north into north-east Colorado. There was, basically, an identical shear environment as on June 2, favoring some rotating storms, but with less buoyancy. Storms fired along the Front Range of the Rockies southwest of the Cheyenne Ridge late in the afternoon. The first storm I intercepted was near Fort Morgan. It briefly rotated and produced gustnadoes. However, it was high based, developing in the moisture starved area, but would later become a supercell, albeit non-tornadic, as it moved into richer moisture near Burlington TX.

A second storm north of Interstate 76 in the same area actually had a weak hook echo at that time, but, as was the case the day before, the whole pattern went "downhill" as the weak shear environment allowed outflows from neighboring storms to slosh through updraft areas, converting all the storms in this portion of Colorado into another, though weaker, Mesoscale Convective System.

I overnighted in Sterling CO, with a view towards the southeast, watching gorgeous mammatus on the backside anvil of the departing storms.

June 4

Briefly Rotating Storms in the Nebraska Panhandle

I was joined by Head of the Department of Geosciences, Prof. Lisa White (middle) and my graduate student Elizabeth Frieberg. We had a reprise of the previous two days, with shear slightly favorable for rotating storms, but meager moisture. and instability (both forecast and in the actual soundings for the area). Storms did fire in the Nebraska Panhandle, where upslope flow of southeasterly winds were occurring. The storms had an HP supercell look, with large preciptation filled bell-shaped lowering on this one. Wet microbursts (downbursts) surrounded us.

The storms once again coalesced into a Mesoscale Convective System, and we spend the night in Burlington, CO.

June 5 and 6

Calling it "A Chase!"

The morning map showed even worse shear, but better forecast buoyancy--with the target southwest Kansas. While some picturesque rotating storms probably would form early, I expected the inevitable formation of a MCS again, which would roar southeastward. Even any supercells that formed would be taking me further away from my flight the next day in Denver.

So, with the memory of an astounding number of tornadoes seen and captured on video or digital still photography in my mind, I called it a chase for 2004.

Instead, we went into Boulder CO...where I went on my favorite long run up Boulder Canyon for a 11-12 mile round trip, a workout at the local gym, and treating ourselves to the latest Harry Potter movie (5 out of 5 possible Stars in my rating system).

Thanks to those that joined us or me on the chase this year, Chuck and Vickie Doswell, as usual, Matt and Betsy Crowther, Steve Sponsler, the ever smart-@@@ish Steve Hodanish, Scott Landolt, Mike Umscheid and Jay Antle. It was enormous fun, and an amazingly successful exercise in scientific research. See you all again next year.