STORM TRACK: September 30, 1986 (Volume 9 Issue 6)

After having viewed two brief tornadoes which developed from a very "dirty" (precipitation obscured), modified (collapsed) supercell east of Altus, Oklahoma, Chuck Doswell and I drove south of the Red River, hoping to find a "cleaner" storm. A visually distinct and straight anvil edge at the south end of a thunderstorm cluster, southwest of Wichita Falls, lead us to believe that "tail-end Charlie" was a near steady-state supercell. We verified this when we reached Point "A" on the enclosed map.

We saw an an intense, rotating chase updraft about ten miles west of "A", with a nearly transparent rain/hail curtain beneath the northeast-flank, and rotating rain curtains beneath the mesocyclonic updraft. As the storm approached "A", our east to west inflow increased from a sustained 25 knots to a steady 40 to 50 knots.

The inflow acceleration was probably due to inflow being "wedged" into a narrow channel ahead of the wrapping outflow associated with the rotating rain curtains. A constant, low-pitched roaring sound (hail?) was present, as was frequent in-cloud and occasional cloud-to-ground lightning. One inch diameter hail fell at "A" as the leading edge of the rotating updraft came overhead, and we fled eastward. (Reports of grapefruit size hail came from west of Archer City.) At "B", we observed a small but well developed funnel cloud near the north side of the updraft base where the inflow and rotation seemed to be concentrated. The precipitation core was gaining more of a solid appearance. Could this indicate a strengthening temperature gradient along the pseudo-warm front and a possible contribution from the solenoid term of the vorticity equation as tornadogenesis ensued?

Taking farm road 2581 south and east from Archer City (where tornado sirens were blaring at this time), we saw the tornado form very quickly from the wall cloud at point "C". Rotating rain curtains which previously hampered our view parted almost as if we were privileged to see the tornado form! The funnel tapered sharply from cloud base and quickly grew into an impressive, large, cone shaped tornado about a mile from our position.

After several minutes, the bottom of the cone dissipated, leaving a very blunt, truncated cone with a ground-based dust whirl. The tornado then became obscured by rain and we only had several brief glimpses as it continued on a path to within a mile south of Windthorst. We experienced estimated 50 to 60 knot rear flank downdraft winds from the southwest. We were lashed by brief periods of heavy rain from the rotating rain curtains. At the intersection of Rt. 2581 and Rt. 281, we talked to a motorist who had been battered by baseball-size hail in Windthorst. We never saw the tornado again, but did photograph the parent storm from "E" and "F". The structure was one of a huge corkscrew Cb with considerable overhang on the south flank. The cyclonically-wrapping flanking line had one or two vertical towers adjacent to the main storm tower, with a large laminar appearance (likely due to strong capping). East of location "G", we observed a severe downburst just north of farm road 174. The downburst levelled several trees, as we watched, and culminated in a fairly large dust whirl which rapidly broke up. This was the last severe weather we encountered.

F2 damage occurred to trees, mobile homes, and barns southwest of Windthorst. Several homes were unroofed and a car was lifted from the road and thrown against a barbed wire fence. Two occupants had sustained minor injuries. Several farms were destroyed north of Rt. 174. One farm house in particular had only one felled wall left on the foundation (F4). In talking to the farm owner, we found he narrowly escaped death. He saw the dark cloud approach, and although a tornado could not be seen, he grabbed his wife and kids and drove to a shelter at his brothers nearby farm. The farmer sensed that the storm was bad. (I promised to bring this farmer a print of the tornado so he can hang it on his fireplace when his home is rebuilt.)

Editors note: Talk about chase strategy. Sampling two tornadic thunderstorms at their peak on the same day in two different states is truly amazing.