WARP CHASE

BY TIM MARSHALL

from Storm Track, Sep/Oct 1989

I've often thought about chasing storms by airplane, but the expense in doing so, coupled with the remote odds of catching a tornado, had kept me from going that route. That is until June 6, 1989! Actually, I had no intention of chasing that morning. The weather situation seemed less than ideal when I analyzed the upper air soundings the previous evening. The 00Z soundings for Midland on June 6, showed weak low and mid-level winds, less than 10 knots from the surface to 700 mb. Amarillo's sounding was not much better with winds up to 16 knots at 700 mb. Throughout West Texas, the surface pressures were high, around 1011 mb, and surface dewpoints were marginal in the upper 50's. Yuck! Sure there were favorable features such as a dryline in West Texas, a strong upper jet, and an approaching short wave. I was aware of SELS optimism about the day, but I've learned not to depend solely on their forecast. Besides, it was Tuesday, a workday, and I had already taken most of May off to chase storms. So I headed out to work.

About 10:30 am, Phil Sherman called me and said the weather situation had really improved in West Texas. The changes in wind direction (WD) and wind speed (MS) over 12 hours at Amarillo and Midland were incredible:



Look at the incredible increase in the low level wind speeds and the sharper turning of wind direction just above the ground in both soundings between 00Z and 122! Phil said the updated SELS outlook at 15Z now called for "significant tornado potential" for West Texas and they had a moderate risk of severe storms for that area. Other improvements included the deepening of surface-based moisture throughout West Texas. The dewpoint at Midland went from 59 degrees at 11Z to 65 degrees at 15Z. By, 15Z most dewpoints throughout. West Texas topped 60 degrees.

I felt like Mr. Bill: Ooooh Nooo! Mother Nature was taunting me again There I was in Dallas, 400 miles away from where I ought to be, at 11 am. I knew it was a seven hour drive to Amarillo. So, I thought about flying out there and renting a car (a $300 decision). I could just see me in the next funnel funny, spending all this money on remote odds only to be skunked by the dryline again! I wanted to be sure about tornadoes.

I asked Phil to call me back after the noon observations to see if: 1) convection had occurred somewhere along the dryline, and 2) to better focus in on which town I should fly to. At 12:30 pm, Phil called again and said some convection was going on in southwest Kansas. He said the

Texas Panhandle looked best for the southern end of this development as it was north of the upper jet maximum, and was on the leading edge of the northward surge in moisture. So, I booked a 2:30 pm flight from Dallas to Amarillo and rushed home to grab my chase equipment. While at home, I accessed the 1 pm hourlies on my home computer in order to plot a surface map later on the plane. I dashed off to the airport and arrived at the gate 15 minutes before takeoff! There was no waiting to board the plane, as few people were on this flight. I knew my luck was running hot when I heard the plane was on-time for departure and we were #1 for take-off.

As the plane accelerated down the runway, I saw the cars on nearby streets as well as the clouds above stop suddenly, then reverse direction. imagined I was in a time machine, warping westward. My anticipation grew as I plotted the surface weather map and watched the weather come to life right in front of me. Ahh, there was a surface low in southeast Colorado with a dryline extending southward along the Texas-New Mexico border. The surface winds were gusting to 30 knots from the south at Amarillo; the surface dewpoint rose 4 more degrees in the past three hours to 64!

I gazed out the airplane window, squinting my eyes westward, and watched a pair of anvils come into view. Whew, I was relieved to think I was going to see something. The northernmost anvil was on a storm near Liberal, Kansas and was already a hundred miles long. As we descended into Amarillo, we flew parallel to a second, smaller anvil on a storm to our south near Dimmit, Texas. Both storm anvils were pointing east. We had quite a bumpy landing in Amarillo as we pierced through the broken strato- cumulus layer and encountered strong low-level cross winds. We were at the gate in five minutes.

The plane emptied quickly and I was off to the car rental counter. My luck couldn't have been better. As I rushed up to the rental counter, all three employees simultaneouly said to me, "May I help you?" There was no waiting! I was off to the storm in ten minutes. Now I had a decision to make. Which storm should I go after, the one at Liberal or at Dimmit? I quickly checked my road map. Liberal was about 200 miles away, Dimmit only 60. There was no time to waste. I chose the nearest storm as my target. I also believed my odds would be best in the dense road network of West Texas than on the sparse roads further north. Bolting south on I- 27, I was relieved to find the speed limit was 65 mph, there were no towns to go through, nor any road construction or farm vehicles to slow me down. All this plus a wonderful view of the storm to the south. Nore good luck.

At 4 pm, I could see a crisp, thick anvil extending from a large cloud tower, however, the anvil was not backsheared. A flanking line extended west from the main cloud tower. Passing Canyon, Texas, I heard on the weather radio that a Tornado Warning was issued for Northeast Lamb County as a tornado had been indicated by radar. I took lots of pictures.

Looking south at the Plainview storm at 4:10 pm.

Over the next thirty minutes, I watched in awe as the storm exploded into the sky. The flanking line was absorbed into a single cloud tower; the anvil blossomed into a giant, backsheared disk, with knuckle shaped edges. A large overshooting top was noted at 4:28 pm; the storm was definitely heading southeast, a right mover. It was getting dark to the south, in contrast to the clear, blue skies behind me. Passing Tulia at 4:45 pm, the weather bulletins on the radio were becoming serious. The announcers voice quivered: "We have golfball-size hail at the KVOP studio here in Plainview. The tornado warning has been reissued until 5:45 pm for Hale County. Several funnels have been sighted by emergency officials and Skywarn spotters. It is a very dangerous situation, residents of Plainview seek shelter immediately! (pause) Now, baseball-size hail is falling. Citizens of Plainview, take cover immediately!" My heart beat faster as I entered the darkness, the roads were wet, and visibility lowered in vehicular spray. "I can't believe I'm here watching this", I said after leaving Dallas only two hours ago! "Incredible backsheared anvil. No question in my mind this is it. A monster Cb."

Only 9 miles from Plainview at 4:50 pm, I saw a long, thin funnel extend from the north side of an eroded updraft through light rain. The funnel lasted 14 minutes. At 4:54 pm, the KVOP announcer says: "Tennis ball size hail is falling in Plainview. We are still under a tornado warning. A brief touchdown occurred moments ago." As I rounded a curve in the road where I-27 junctions with US 70 at 5:08 pm, I shouted "WE HAVE A TORNADO SOUTHEAST, TORNADO!". A large tapered funnel reached for the ground sending up a thin veil of dust. I continued toward south Plainview and watched the tornado move northward toward me. Three minutes later, the tornado roped out, but not before moving over the Cargill grain elevator toppling several metal grain bins.


Plainview tornado to my south at 5:10 pm.


Rope stage of Plainview tornado at 5:12 pm.

A few satellite vortices formed overhead in mid-air about 5:12 pm. I exited I-27 in south Plainview and was at the Cargill elevators at 5:15 pm. Power lines were downed, debris and insulation was everywhere. The air was still, the ground wet, The only sound was of distant sirens coming toward me. I stopped long enough to take a few photographs, then it was off to continue the chase.

Wall cloud and golfball hail near Lockney at 5:35 pm.

The storm eventually died out near Floydada without producing another tornado. As the chase wound down, I met part of the Texas Tech Team in golfball-size hail. Through their fogged car window they signaled SUCCESS with a "thumbs up". Our cars received a few souvenir dents from the hail. But there was still time to chase a second storm to the southeast. I followed the storm to Hamlin before giving up and heading back to Amarillo. It was 1 a.m. when I reached Amarillo after driving a total of 480 miles. My average speed to the tornado was 185 mph (or F3)!