April 21, 2010

Statistics:

Initial Target: Shamrock, TX
Departure: Westchester, IL 2:00 pm April 20
Arrival: Childress, TX 8:30 pm April 21
Intercepts: Lockney, TX
Tornadoes: 0
Hail: None
Wind: Non-Severe (not measured)
Features: RFB, Hail Shaft, Rainbow
Miles: 1,253

Summary:

Upslope play in the TX panhandle. Targeted eastern TX panhandle for storms coming off the caprock stopping in Shamrock, TX for lunch. Dropped south to warm front near Childress then west to cu field. Caught severe warned storm near initiation southwest of Lockney, TX. Intercepted noting very high base and little motion, yet pretty structure. Watched storm until its death before jumping on a left moving, potentially anticyclonic supercell near South Plains, TX. Noted pronounced hail shaft and rainbows. Met Danny Neal, Mike Nelson, and Adam Lucio in Childress, TX for dinner and hotel room.

Crew and Equipment:

Solo chase.  Equipment:  Kenwood TH-F6A Tribander, Dell Inspiron Laptop.  Kyocera data card and router, Holux 236 GPS, Robotic camera dome with Sony XR-520V.

 

Video:

 

Details:

This was the first day in a three day marathon chase trip. Wednesday looked like a marginal chase day and probably not worth the drive to the Texas panhandle by itself. Thursday's setup, however, looked like it could be a big tornado day and was over the exact same area, so I decided to arrive early and hopefully get a surprise on "the day before the day."

With modest dewpoints, an ill defined dryline and the upper level trough still well off the west, Wednesday was missing many of the components necessary for a more widespread severe weather event. Still, easterly surface winds would be creating upslope flow across the Caprock that would initiate storms, with strong solar heating creating moderate instability of 2000 J/Kg. I hoped the combination would be enough to fire off a few photogenic supercells before the lack of shear would cause the updrafts to collapse in on themselves. I targeted Shamrock, just east of the Caprock, where I'd have good road options in all directions as I was unsure exactly where initiation would take place.

I packed the van for a three day marathon run out to the plains with a large cooler filled with drinks and food, and a mattress with blankets to sleep on. Ben Leitschuh was originally supposed to be my chase partner for the three day run, but he bailed the morning I was to leave. I was doing a multi-day run out to the south plains solo. My trip down was rather uneventful. I left Westchester at 2 pm and stopped for the night somewhere off I-44 between Tulsa and Oklahoma City. I found a gravel road a couple miles from the highway with a turnout and camped out in the van for the night. The turnout had a rather steep grade so I spent all night rolling in the corner, however.

I was up bright and early and made it to Shamrock, TX by lunch time. Along the way I passed a pickup towing a very long flatbed trailer. The driver was driving erratically, swerving all over the place. At one point he drove completely off the interstate into the media. I thought he was going to lose it for sure, but he pulled it back onto the road.

Shamrock, looks like a cute town with its dusty, western appearance. With some time to kill I looked for a regular sit down restaurant for lunch. There were none. The few places that are there were all closed. I got Subway instead. I pulled into the rear lot behind the Best Western to setup the dome on top of the van. One of the employees came out the back door and said to me, "Y'all aren't allowed to setup here." I was the only one in the lot, but clearly they don't like chasers. I had no problem moving as it was their parking lot, but I was slightly irritated since I already had half of my gear unloaded out of the van and now I'd have to pack it back up. Shamrock, Texas is good for maybe a fuel stop and its crossroads, and that's about it. With all the restaurants closed and the hotel hostile towards chasers, why else would I stop there? A dusty rat hole.

The eastern half of the panhandle was socked in with clouds, which were reinforcing a warm front from about Lubbock to Childress. I decided to drop down to Childress where I could catch storms coming off the Caprock A nice cu field was developing along the diffuse dryline to the west and it looked like towers were starting go up. I zig zagged my way through Turkey, TX and through the Caprock canyons and came out on top near Lockney, TX. Storms were now developing up and down the dryline. I got gas in Lockney just as a cell to my southwest went severe warned. A few miles south of town I pulled over with the base of the storm in view:
A nice low precipitation (LP) supercell. This storm was quite deceiving. With a 60 Dbz return on radar it looked like it should have a monster precipitation core. The radar also indicated the storm was still 15 miles away. It didn't look that far away. I started looking around thinking I had the wrong storm. I didn't realize though that the base of the storm was so high that it made it look a lot closer than it was from my vantage point. The LP nature of the supercell also meant that most of the precipitation was falling as large hail instead of rain, which does create a dark precipitation core. Indeed, baseball sized hail was falling out of the right side of the storm pictured here. LP supercell base and updraft tower with inflow band feeding in from the left:
I watched the storm for quite awhile noting a little scud activity under the base, but not too much motion otherwise and not much of an attempt at a lowering. I finally decided to drop further south and get closer to the base. Still a couple miles out it became apparent how high the base of the storm was. It would be a long way down to the ground for any tornadoes today.
The base of the storm started to shrivel up, which meant it was on its way out. Any hope that this storm would produce a tornado quickly vanished. I studied the radar seeing what else there was in the area to play. There were decent looking storms to the southeast, but I imagined they would take some time to get to and would probably suffer the same fate as this storm. There was an odd storm just to my northwest, however. It had originally gone up quite close to the storm pictured here, but had taken a northerly course, which meant it was probably a left split, elevated, or would not be favorable for tornadoes. The storm now looked the strongest of the group and with its odd movement and radar appearance I suspected it might be an anticyclonic supercell.
Looking back northwest at the Mudpuppy and the north moving storm. An anticyclonic supercell rotates clockwise, which is opposite to most supercells in the northern hemisphere. I suspected that it started as a left split, and it became rooted to the surface, able draw inflow from the surface winds that had backed almost northeasterly. The lightly sheared environment allowed the storm to persist counter to how most storms rotate.
I made a run for the northern storm which was moving quite a bit faster than the rest of the storms that were drifting east-northeast. I made one last look to the west at the initial storm I had intercepted as the base continued to evaporate and would soon leave behind an orphaned anvil. Dieing storm with sunrays and a narrow rain shaft on the right:
A cleared some of the low lying clouds as I approached the left moving storm. The storm had a very robust updraft tower, a small back-sheared anvil and overshooting top. All indicated that it was a powerful storm. My suspicions that this storm was anticyclonic were further evidenced when the radar indicated that there was low level rotation on the northern flank of the storm. The TVS marker that showed up on the north end of the storm typically shows on the southern flank.
If this was indeed an anticyclonic supercell, in order to effectively chase it I now not only had to catch up to it, but I had to get around to the north side of it. Looking north at the storm and precipitation shafts on the right, and a flanking line stretching off to the northwest on the left:
The rain and hail shafts of the storm caught the light as I drove north and a rainbow skipped along it. It was a very picturesque sight. I also had a view of what might be a rain free base on the northwest flank of the storm. Typically the RFB forms on the southwest flank, but storm structure is mirrored on anticyclonic supercells.
I got about parallel with the storm before I ran out of road options as the storm approached the Caprock. I made a run east towards the storm to see if I could better look at the rain free base. Instead I was greeted by a totally awesome view of the storm's hail core. Struck by the sun, the hail shaft shone white. The churning turbulence within it reminded me of a cascading waterfall or a tumultuous avalanche. It was an amazing sight.
I got a little closer and a brilliant rainbow appeared. Out of roads and with this storm and all others starting to wind down, I called it a chase. I waited for the core of the storm to pass and then continued east down through the Caprock in light rain, looking for a place to get dinner and stop for the night. I wound up meeting Adam Lucio, Danny Neal, and Mike Nelson in Childress for dinner. We found a greasy little diner called The Kettle that was open all hours and got some badly needed grub as it had been about 10 hours since I had lunch in Shamrock. Adam, Danny, Mike, and I decided to split a room for the night at the Comfort Inn. Little did I know that their snoring and nocturnal noises would keep me up all night.
 
Conclusion:

For a chase with low expectations this was not a bad chase. I caught a pretty, high based LP supercell and then saw a really neat left moving storm that might have been an anticyclonic supercell. The hail shafts and rainbows were awesome sights as well. For a day in which I didn't expect tornadoes, just pretty storm structure, this day did not disappoint. I didn't have to go out of the way for it either since the next day's target looked to be in the same spot.

 

 

Lessons Learned: 

  • Don't waste time in Shamrock, TX