May 31, 1995

Vortex NCAR Aircraft Mission #12

Takeoff time - 1903 UTC
Landing Time - 0200 UTC

Summary:

VORTEX was down on this day. The Electra departed Will Rogers Airport on a solo mission in search of severe convection near Abilene. The greatest instability and jet-stream dynamics appeared to be located over this area. The flight path took the Electra over Frederick, OK before heading south toward Abilene at 17,000'. We immediately encountered intense convection northwest of Abilene. These cells appeared to initiate along a mesoscale outflow boundary that was clearly identified on visible satellite imagery and NEXRAD scans. Two cells were apparent as the plane descended to 1000' AGL. Racetrack patterns were flown on the southern cell at 2006 UTC. Equivalent potential temperatures were approximately 350 K in the boundary layer. Unfortunately, a tornado was reported near Snyder on the northern storm. The two cells appeared to merge around 2100 UTC and a large hook echo and mesocyclone developed near Sweetwater, Texas. A tornado-like funnel was sighted at 2118 UTC. Another intense cell formed to the south of the primary cell making the racetrack patterns difficult to execute. At 2143 UTC, the Electra flew to this southern most cell and executed numerous racetrack patterns until 0030 UTC. ELDORA was down 2120-2149 UTC. It is uncertain at this time whether the down time resulted in a loss of tornado data.

Roger Wakimoto