May 31, 1995
Vortex NCAR Aircraft Mission #12
Takeoff time - 1903 UTC
Landing Time - 0200 UTC
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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