June 12,
2005
Storm Chase
Northwest Texas
Editor: Putnam
E. Reiter
Forecast/Setup -
Risk Area: Moderate Risk -
enhanced, 10% hatched area on tornado prob graphic.
Initial Target Area: Elk City
Seemingly the atmosphere
finally started to cooperate with storm season. After a quiet Memorial Day
weekend (a rare event in Oklahoma) June got active. This chase looked like
the "grand daddy" of chases a few days out. However, as we got to the
actual day many issues popped out that reduced the overall threat.
For several days the models
progged a longwave trof to sit out west. This combined with seasonable heat
and moisture meant that the atmosphere would be quite favorable for severe
thunderstorms. Several days were progged to provide the best severe
weather, however the focus was on Friday and today (Sunday). In the end the
best days where Thursday and Saturday, rather subtle days in the longwave
pattern. Thursday was the best day of the three and Saturday wasn't too
bad.
The synoptic pattern really
didn't change much for this day, considering the prior few days. The main
thing was that the longwave trof was progged to lift out today. A surface
low was progged in the Texas Panhandle was a cold front in CO/SW KS and a
warm front in southern Kansas. All of this was rather far south for
mid-June. Decent wind fields existed aloft with favorable speed and
directional shear. For several days the models progged low dewpoints across
parts of SW Oklahoma. This seemed a little strange and was written off.
Ohh and Tropical Storm Arlene was of interest also, in case it cut off the
moisture supply.
Saturday afternoon numerous
thunderstorms developed in the Texas panhandle and moved towards northern
Oklahoma overnight. This setup a frontal boundary in northern Oklahoma. In
most cases for late spring cold fronts turned into warm fronts and lift
north. However, very strong southerly flow was in progress with isentropic
lift occurring along the frontal boundary. This kept storms going north of
the cold front and also resulted in a slow southward drift of this boundary.
The atmosphere did cooperate
by warming up with little in the way of cloud cover. The dewpoint drop did
occur in southern Oklahoma behind an early afternoon shortwave trof. As the
trof passed, dewpoints rebounded. The big problem of the day was the cold
front, which moved south at about 10 mph. Surface based storms eventually
developed in west Texas east of Lubbock. The storms formed along the
dryline and looked kind of rough at first. After 30 minutes they looked
like supercells with three of them lined up. All three produced tornadoes,
if only briefly. A fourth storm developed farther south and also produced a
tornado.
No tornadoes occurred in
Oklahoma today.
SPC Products: SWO
Day 1
Risk
Area -
Tornado Prob
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Damaging Wind Prob
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Hail Prob
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Storm Plot
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LSRs
Surface
Maps:
Temperature
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Dewpoint
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Wind Speed
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CAPE -
LI
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Moisture Convergence
Text
Products:
Watches
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Mesoscale Discussions
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Warning Decision Updates
Mesoeta
00z Initialization:
Surface Pressure
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850mb Temperatures
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850mb Dewpoints
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850mb Windspeed
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850mb Vertical Velocity
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850mb Relative Humidity
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700mb Wind
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700mb Temperatures
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700mb Relative Humidity
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700mb Vertical Velocity
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500mb Vertical Velocity
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500mb Temperature
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500mb Vorticity
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500mb Wind
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500mb Relative Humidity
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250mb Wind
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250mb Relative Humidity
The Chase -
Team 1 - Andy Wallace, Ray
Hardy, Rob Ferguson, and Putnam Reiter
Team 2 - Allen Wright, Mr. Wright, Brandon
Miles Driven - 530
Departure Time - 13:00
Return Time - 00:00 06/13/2005
Given that this was mid-June
and chases this time of the year are rare, we didn't waste much time
deciding on whether or not to go. We did hurry up and leave since SPC got a
little excited and issued a watch around 12:30pm. We headed on south after
gathering the group. Getting to Chickasha we grabbed a quick bite and
continued south on I-44. Looking at the data on the way south we noticed
the decreasing dewpoints in our area and the slow southward motion of the
front. We got to Lawton and headed west on Highway 62.
As we arrived in Altus we
noticed the CU field was improving but the front wasn't far away either.
So, we headed on west towards Hollis. As we got west of Hollis the front
was just to our north and we knew it was time to scream south. No sign of
surface based storms in Oklahoma, so we committed to Texas.
We got to Childress as noticed
storms had developed east of Lubbock. This looked good as they were a long
ways from the cold front and in a good area. However, when we saw them on
radar they didn't look that good. We sat in Childress for a while, hunting
for data. About the time we got data back, we received a tornado warning
for this activity. Radar showed three supercells had formed from the
earlier activity.
We took off south to catch up
with the activity, which was going nowhere fast. Unfortunately we took a
wrong turn and headed towards Matador. Wasting about 30 minutes, we
reversed course and went back south towards Guthrie. Unfortunately it was
too little too late. We got to the first storm and saw some decent motion
within 10 minutes the storm's inflow got cutoff by the southern storm. We
watched a spectacular dissipation. We headed south to the next storm and it
merged with another storm before we got to it. The fourth storm wasn't too
far out of reach, so we went after it in Aspermont. Getting south of
Aspermont we watched the updraft region of the storm and it just wasn't
doing it for us. Knowing that we had a long drive ahead of us, we turned
back on Highway 380 and then went to Wichita Falls and on to Oklahoma City.
Thanks to Jay for data
support.
Lessons Learned -
- The only thing is that we
sat in Childress too long looking for data instead of trusting our
forecasting. The storms in west Texas looked iffy at first but another 30
minutes allowed for supercells. Had we kept going, we'd probably seen a
tornado. The other thing was navigation where we turned west at a point we
should not have. Of course some of that could be due to not knowing the
area.
Multimedia -
- None
Encounters -
Engaged Storm: South of
Paducah, Texas and South of Aspermont, Texas
Tornado: No, No
Funnel: No, No
Hail (larger than 0.75 inches): No, No
Wall Cloud: Yes, No
Wind (above 57.4 mph): No, No
