Return to Case Study Page
The first storm targeted by VORTEX occurred in the Oklahoma
Panhandle in the middle of the afternoon. The storm was on a
surface front. AN elongated mesocyclone formed near Elmwood in
Beaver County, and moved toward Laverne and Rosston. This storm
produced softball-size hail, severe surface winds, and a brief
funnel cloud, but no tornadoes. It was well-sampled by VORTEX.
After the Elmwood storm transitioned into a weaker HP supercell,
the VORTEX armada moved south toward the eastern Texas
Panhandle. We bypassed a storm near Spearman because we felt it
would also be an HP storm. A tornadic storm had developed near
Pampa and was moving NNE, but we realized it was over open
country in the Canadian River bottomland west of Canadian, TX,
and would not approach any major roads for at least one hour.
Therefore, we targeted a new tornadic storm near McLean TX (on
I-40 in the eastern TX Panhandle).
Unfortunately, the Pampa tornado had sufficiently destroyed the
power distribution network that no electricity was on in any of
the communities that we traveled through in the TX Panhandle.
We were told that power would be out for at least 24 hours.
This means no gasoline pumps! Three of our teams ran out of gas
while looking for electricity around Shamrock. Three others ran
out of gas near sunset.
However, most of the armada intercepted the McLean storm near
McLean. The NOAA P-3 and the NCAR Electra had already been
gathering data on this storm for over an hour, including the
spinup of a brief tornado just north of McLean (and perhaps
others between McLean and Clarendon).
A large, violent tornado formed just south of Kellerville and
moved to a point NW of Wheeler, TX. Surface teams were on
several sides of this tornado. South of Kellerville, the
pavement was completely removed from highway 1443. The mobile
scanning Doppler obtained data on this tornado scanning toward
the southwest.
Meanwhile, a twin supercell was also moving NNE just west of the
target storm. This storm also produced (perhaps several)
tornadoes between Alanreed and Mobeetie.
The target storm underwent another phase of cyclic
tornadogenesis just southeast of the demise of the Kellerville
tornado. This occurred between Wheeler and Briscoe. The second
large, violent tornado that we observed developed about 6 miles
southwest of Allison, TX. It moved directly toward Allison, but
veered to the left just prior to striking the community, and
passed 1.5 miles west of town. It then meandered to a position
about 3 miles northwest of Allison and remained nearly
stationary for a period of about 20 minutes.
This tornado was well-sampled with the mobile mesonet, and
perhaps with the mobile scanning Doppler, as well as with the
NOAA P-3. Teams were positioned SE-NE of the tornado, as well
as west of the tornado as it crossed the highway west of
Allison. The mobile scanning Doppler as well as WSR-88D
depicted as many as four tornadoes &/or mesocyclones occurring
simultaneously within an area roughly 12 miles on a side north
of the Briscoe/Allison road.
Damage surveys are being conducted today, and an aerial survey
may take place tomorrow (Saturday). We will post the results of
the survey work on this email list, and we will post survey maps
and details as part of the large volume of VORTEX data on the
World Wide Web.
Finally, it should be noted that Chuck Doswell, chasing
independently with Al Moller, obtained the best, most stunning
tornado footage I have every seen. The footage was shot of a
tornado moving through the south side of Pampa, TX, from a range
of about 500 meters. This was a violent tornado that filled the
sky with debris. There is no doubt that this footage should be
tremendously valuable for tornado photogrammetry work.
Erik Rasmussen
Jerry Straka