May 24, 2002
Storm Chase
Southwest Oklahoma and Northwest Texas
Editor: Putnam
Reiter
For Hookecho.com this chase season
has been rough. This is exemplified by reviewing Oklahoma's severe weather
events the past few months. The current number of tornadoes is around nine with
none of them during the daylight hours for 2002. Our last big event was October
9, 2001, with a few note worthy events for 2002. Memorial Day weekend has
brought severe weather events the past seven years and we had hopes that 2002
would be the eight.
Forecast -
Recent numerical model performance
has been less than ideal. This combined with persistent Canadian cold fronts
has made forecasting in Oklahoma difficult. We had been watching Memorial Day
weekend for a while, hoping that we might break our tornado drought. Model
prognostics leading up to Friday presented some severe weather signals and Storm
Prediction Center (SPC) outlooks starting on Wednesday gave further indications.
On Friday a southern stream
shortwave trof was predicted by the models to move across parts of the Texas
Panhandle and Oklahoma. A dryline was positioned in the central Texas Panhandle
and was thought to progress east during the day to near the Oklahoma border.
Additionally, a cold front was to move southeast into northwest Oklahoma and the
north Texas Panhandle.
We picked southeast Oklahoma as a
starting point and this was later confirmed as a good spot by the 13:00z and
16:30z issuances of the Day 1 Outlook. A moderate risk was up for this area
with a 15% chance of a tornado.
The Chase -
Team 1 - Jim Riley and Putnam
Reiter
Team 2 - Preston
Miles Driven - @500
Departure Time - 11:00 CDT
Return Time - 01:00 CDT - 05/25/2002
The team met up in Lawton around
13:30 CDT about the time a mesoscale discussion (MD) was issued by SPC. A
tornado watch was likely forth coming for parts of Oklahoma and the Texas
Panhandle. We headed west on Highway 62 to Altus. Once in Altus we learned
that storms had developed near Childress. We continued west on Highway 62 to
Gould and then went south of Highway 5. We sat south of Gould for a while as
the storms moved northeast into our area.
From about 15:00 CDT to 18:00 CDT
we sat south of Gould watching storms develop and move to our north. One storm
passed to our south. Several wall clouds developed and dissipated about as
quick. The back edge of the storms moved into the region around 18:00 CDT, we
started following the back edge. West of Duke on Highway 62 this storm produced
a wall cloud. From what we can tell this was the first such rotation feature
from this storm as we had watched it develop south of Hollis and move towards
Gould. The storm wrapped up over Duke with the rotation area reforming to the
southwest about 1-2 miles. As the storm moved east towards Altus and just north
of Highway 62 it continued to show signs of low-level circulation. The storm
approached Altus and started to lose its features and eventually lost the low
level circulation. It may have produced a brief tornado near Altus.
We left this storm and went south
out of Altus on Highway 283 towards a storm near Quanah, Texas. After getting
into Texas we took Highway 91 to Chillicothe, Texas. The time was near 19:40
CDT. We started to get storm scale features near Chillicothe, seeing a lot of
low hanging clouds on the northeast side of the storm. We turned northwest on
Highway 287 and drove about two miles northwest. Seeing that this was an error,
we turned around and drove about 2-3 miles southeast of Chillicothe. We watched
the storm as it approached. As the storm got near we noted low level rotation
to our southwest. This area quickly came together and produced a tornado for
about 30 seconds. Some noted two areas of rotation, but we had a difficult time
noting this. The storm had HP Supercell characteristics with the south view of
the storm obscured by rain. We drove into Vernon and then south on Highway 183
to get south of the storm. As we did the circulation area disappeared and we
could actually see the sun through the rain. About this time we got blasted by
50mph winds with possible gusts to 70mph.
By this time it was 20:15 CDT and
the storms had started to form a squall line. We headed back to Lawton via
Highway 183 and Highway 62.
Lessons Learned -
- Watch storm evolution for
sudden changes, such as the high winds that damaged the chase vehicle south
of Vernon.
- We did not shoot enough
video, about ten minutes total.
General Observations -
Recently a lot of attention has
been directed towards chasers that behave poorly by doing such things as driving
fast or parking in the middle of the road. During this event our chase crew did
not see any problems. There were a lot of chasers out and for the most part,
everyone seemed to obey the basic concepts of good chasing. Of course we were
in a small area, but I think this is noteworthy.
Another item to note is that with
all the low hanging scud, very few tornado reports were made. It was real
difficult to distinguish between scud and legitimate rotation. Despite that
reports over the amateur radio system fit the storm scale environment nicely.
Multimedia -
-
Picture 1 -
South of Gould, OK, facing southwest looking at anvils. 15:56 CDT
-
Picture 2 -
South of Gould, OK, facing northwest at a small and brief wall cloud. 16:32
CDT
-
Picture 3 -
South of Gould, OK, facing northwest at a small and brief wall cloud. 16:52
CDT
-
Picture 4 -
South of Gould, OK, facing northwest towards a rain-free base. 17:13 CDT
-
Picture 5 -
West of Altus, OK, facing north towards a wall cloud. 18:37 CDT
-
Picture 6 -
South of Vernon, TX, facing west looking through rain curtains at the Sun.
20:27 CDT
Video
- Tornado, west of Vernon facing south-southwest. 19:49 CDT
- Note:
Windows Media Player 7.1
or newer is required for the above video.
Encounters -
Note: We intercepted several
storms, but will focus on the Chillicothe, Texas storm for this area.
- Tornado: Yes - west of
Vernon, lasted 30 seconds.
- Hail: None
- Wind: Measured 50mph,
estimated 70mph.
