Tuesday, March 20, 2012
18 March 2012: Willow, Oklahoma tornadoes & structure
Scott Currens, Bob Fritchie and I converged on the Shamrock, Texas Taco Bell, and tried the Doritos Locos Tacos while monitoring radar on our phones.
When it was clear our target area had mixed out via an elevated dryline, we drove south and intercepted what we'd called the "Childress storm" three miles southeast of Hollis, Oklahoma a few miles north of the Red River. The storm intensified as we approached, but in person looked initially high-based and benign. It looked like an outflow dominant cell struggling with the high dewpoint depressions of its environment, a ragged updraft region and weak convergence. But soon, the first serious wall cloud emerged, and an impressive tail cloud formed as scud collected around a circulation before it crossed our N/S county road. We pursued the storm into Hollis and turned north on 30. Near the airport, we observed the second of many occlusions, this time with more promising signs of tornadogenesis, but the pristine green fields and lack of power poles or wires was too ideal a foreground, I guess.
At McKnight, we made the fateful turn east on E1550, a perfectly fine and well-paved road but without any northern options that didn't terminate at the river. We were stuck driving east. We fell behind, but in doing so we noticed the incredible structure of the supercell. The farther we went, the better it looked.
Taken about 10 miles east of McKnight
This was quite a sight, a seemingly low-topped cell with the stable-layer, polished sheen on deeply grooved stacks. Though we were well to the south and east, far out of position for tornado-viewing, we didn't mind. As Scott Currens said later, "Being stuck on that eastbound road was the best thing that happened." At that point I considered the tornado potential marginal at best--not the last wrong analysis of this persistent little storm. But when it reached the higher theta-e air in southwestern Oklahoma, and the more supportive shear arrived, the show was about to begin.
During the last few miles of our journey to SR 34, the rotational signature on radar increased sharply and a wall cloud emerged in the distance. This was a large, dark blocky wall cloud, the kind that produce tornadoes you can't see when you're more than five miles away. We were probably ten to twelve miles south at this point. Finally we turned north on 34. Somewhere along the way we may have seen the first tornado near Reed, but I wasn't able to shoot it.
We were parked near the fork of 283 and 34, one mile north of Willow, when the elephant trunk tornado descended.
Taken 1m north of Willow, Oklahoma, 0030z
This funnel dissipated but the same circulation produced another fully condensed funnel seven to ten minutes later.
Taken three miles north of Willow about 0038z.
A great March chase with Bob and Scott, a reasonable distance traveled and an unforgettable storm. While it wasn't my first chase of the year (An extended reconnaissance to Lubbock two days earlier isn't worth writing about) it was a gratifying start to the season's opening schedule.