Chief Scientist: Watson/Ziegler Flight Director: Damiano Doppler Radar: Shepherd Pilots: Kennedy/Tenneson Cloud Physics: --- Data Technician: Pradas Radiometer: Westwater Systems Engineer: Lynch/McNamara Observers: Wiscombe,Hazen,Liljegren,Eack,Weygandt Takeoff Time: 1857 UTC Landing Time: 0142 UTC Official Mission Duration: 7.0 hrs Mission Breakdown VORTEX: 7.0 hrs ARM: 0.0 hrs Number of Data Tapes Used: Radar: 1 Cloud Physics: 1 Video: 3Data Systems Log
Radar Data System Log Time On(UTC) Time Off(UTC) Comments 1922 LF only 2246 Start TA 0124 End recording Cloud Physics Log Time On(UTC) Time Off(UTC) Comments 1915 0115 ETL Radiometer Log Time On (UTC) Time Off (UTC) Comments 1850 0115 Excellent data
CAPE and shear was adequate for supercells this afternoon in south-
central and southeastern Oklahoma, along the Red River, and in northeast
Texas. The flight plan was to execute an INIT pattern along with the
ground teams in the vicinity of the east-west outflow boundary and
intersecting dryline. The Electra was grounded due to ELDORA computer
problems.
The P-3 departed OKC at 1857 UTC, heading south and descending
to 500' AGL NW of Ardmore, and encountering the E-W boundary near Ardmore.
We turned westbound along 34N to search for the dryline. However, all we
found was the frontal boundary. We executed one stepped tranerse set
(500', 300' AGL, & above clouds) at 34N. Thinking the dryline was still to
the west, we executed 2 sets of stepped traverses along 33.5N. Again, we
found only the front with clearing skies to the west, scattered Cu
gradually becoming TCu between the frontal boundary and I-35. Flow was
southerly east of the front gradually becoming SE flow.
We broke off the INIT pattern as a Cb developed north of Sherman,
TX, across the Red River and Lake Texoma. We arrived at the Cb at 2240 UTC
which was developing in a field of large TCu. We began E-W radar legs and
descended to 3000' AGL below the clouds at 2255 UTC. We executed 19
Doppler legs on the supercell cluster. The first BWER was observed on the
tail radar at 2327 UTC, as the ground teams went into a ROT-S senario. The
LF radar again provided a wealth of information as the mesocyclone evolved,
becoming rain-wrapped and occluding, with a new mesocyclone forming west
of the old circulation. This evolution probably cycled four times
while the P-3 observed the storm. A county sheriff reported a tornado
NW of Sherman at 0033 UTC. Due to fuel considerations, we concluded
our operations at 0102 UTC, returning to OKC at 0142.
Irv Watson