May 15, 2003
Storm Chase
Texas Panhandle
Editor:
Putnam E. Reiter
Forecast/Setup -
Risk Area: High Risk
Initial Target Area: Hollis, Oklahoma
A cold front passed through the
state on Wednesday. This boundary ended up in southern Texas. A
closed low was progged to approach the region today through northern New Mexico.
As the system approached a surface low would spin up in northeast New Mexico.
A dryline firmed in central New Mexico and quickly mixed east to the central
Texas Panhandle by afternoon. A warm front develop from the low through
Amarillo to Abilene and then points southeast.
Initially the wind fields were
weak at many levels. As the upper system approaches, winds were progged to
increase at all levels. Additionally, there would be some veering from the
surface up to 700mb. The warm front would aid this process by backing the
winds across that area.
Temperatures had been quite
warm across the entire region. This would produce a rather strong cap and
also assist in providing some sensible heat during the day. The 10C 700mb
line was progged to near I-40. Without much energy, breaking the cap would
be difficult. Despite temperatures in the mid 80s and dewpoints in the
mid/upper 60s, getting storm development would be difficult. All models
forecasted precipitation along the warm front during the late afternoon into the
evening hours.
A big complicating factor was
the existence of mid/upper level clouds. Cirrus spread through the area
much of the day. However, this did not impede surface heating that much.
The best storms formed north of I-40 and went up as the 700mb drying/dynamics
moved into the region. The storm near Abilene went up shortly there after.
Very little in the way of activity between I-40 and I-20 until around 22:30 CDT
when the cap was eroded by cold air advection.
SPC Products:
SWO Day 1 Graphics:
Risk Area
-
Tornado Prob -
Damaging Wind Prob -
Hail Prob
Surface Maps:
Temperature
- Dewpoint -
Wind Speed -
CAPE -
LI
GFS 00z Initialization:
Surface Pressure -
850mb Wind
-
700mb
Wind -
500mb
Vorticity -
500mb
Wind
-
250mb Wind
Text Products:
Watches -
Mesoscale Discussions -
Local Storm Reports -
Tornado Warnings -
Misc
The Chase -
Team 1 - Rob Ferguson,
Sarah Davis, and Putnam Reiter
Miles Driven - 505
Departure Time - 11:00 CDT
Return Time - 23:30 CDT
We left Oklahoma City and
headed southwest to Lawton. The whole reason for leaving early was that we
thought things might try to go around 16:00 CDT. We left Lawton around
15:00 CDT and head to Altus where we fueled up. After that we went and sat
near Duke for several hours. We noticed accas moving into the region
around 17:00 CDT and this must have been the 700mb jet max moving into the
region.
Thinking that was really going
to be a late show, we decided to get some food at the Sonic in Hollis. We
then headed on west to Texas where Highway 62 meets Highway 83 in the panhandle.
We sat around some more, by this time we heard of storms in the Oklahoma
panhandle and stuff in the northern Texas panhandle. There was some shower
activity near Clarendon, just to our north. However, it didn't look that
good and about all we saw around us was cirrus.
We got word that the storm near
Clarendon was becoming better organized, so we headed north for a better look.
This was around 20:00 and we knew time was important. The sun was low to
our west and night time would soon follow. This storm got a tornado
warning and apparently had produced one. We got north of Wellington and
really tried to look for features. We could see the backside of the storm
better than underneath. Moisture was thick and seeing much more than five
miles was almost impossible.
Getting a good lead on where
this thing was going, we drove to Shamrock and then headed west on I-40.
The intent was to get to it just as it crossed I-40. This was around 20:45
CDT and daylight was almost gone. We rode up on it and caught a funnel and
possible a tornado in the rope stage. This is noted in the video and you
can probably see that the RFD has wrapped all the way around this feature.
Then we sat and watched the new circulation area. The RFD started to cut
into this feature and it funneled for just a few seconds. After that
daylight was gone and it was time to head home.
We headed back to Oklahoma City
via I-40.
Lessons Learned -
- No major issues on the
chase. We did things very well this time and did a good job responding to
atmospheric features. Rob wanted to go north and this turned out to be the
best idea, in fact he had the good idea to go west on I-40 from Shamrock.
If there was anything iffy it was our forecasting. The dryline was a
none-issue south of I-40 until you reached Abilene. The best stuff of the
day ended up in the Oklahoma Panhandle.
Multimedia -
- In the Texas Panhandle along
I-40, west of Shamrock, Texas.
Clip 1
Encounters -
Storm: 8 West of
Shamrock, Texas
Tornado: No - not sure, but darn close.
Funnel: Yes
Hail (larger than 0.75 inches): No
Wall Cloud: Yes
Wind (above 57.4 mph): No
