May 8, 2003
Storm Chase
Central Oklahoma
Editor:
Putnam E. Reiter
Forecast/Setup -
Risk Area: High Risk
Initial Target Area: Guthrie, Oklahoma
A persistent longwave trof
continued across the western U.S. today. At the surface, very deep
moisture was present across the southern plains with almost 250 mb worth of
moisture. Morning soundings revealed that the atmosphere was already very
unstable and this was progged to increase during the day. A dryline was
located in the Texas panhandle with movement progged into central Oklahoma by
7:00pm.
A shortwave trof was progged to
eject out during the day across Kansas. This is what would push the
dryline to the east. Low 70s dewpoints were based east of the dryline,
rather high for early May. Wind fields from the surface on up were very
strong, as noted by the GFS initialization from this day.
Many things made this feel like
May 3rd. First, was SPC's lack of interest in Oklahoma. Their entire
focus was on NE KS/NW MO. Despite the obvious powder keg across Oklahoma,
they continued the slight risk at 16:30z. The Norman Forecast Office
issued a Moderate Risk for their area at 12:00pm. Finally, at 20:00z
(3:00pm) SPC gets a clue and issues a high risk. To their credit, they did
have CNN camped out in their office.
We knew that north-central
Oklahoma was the most favorable area due to the presence of strong winds aloft
and proximity of the upper energy. Additionally, an outflow
boundary/rainfall max from an overnight storm was located in this area.
The main concern about going west was that the winds were supposed to veer
dramatically across western Oklahoma. We initially thought about going to
El Reno. One reason was to split the risk area due to an outflow/rainfall
max across parts of central/southern Oklahoma. The other was that the
winds were not supposed to veer as much south of I-40. A strong cap was in
place, but should erode during the day.
Storms eventually developed
around 16:30. A few developed south of I-40 near Anadarko and Lawton.
The Lawton storm quickly died while the Anadarko storm intensified and
eventually split. The right mover continued near Tuttle and Minco.
It would go on to produce the Oklahoma City F4 tornado. This storm, after
moving through Moore, Tinker AFB, and Choctaw, moved on northeast towards
Bristow and Tulsa. Once again movement was progged at 30mph, while the
actual movement was 45-50mph.
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 -
Precipitable Water -
850mb Wind -
850mb Temperature
-
700mb Temperature
-
700mb
Wind -
500mb
Vorticity -
500mb
Wind -
300mb Wind
-
250mb Wind
Misc Products:
Watches -
Tornado
Warnings -
Mesoscale Discussions -
Severe Weather Statements -
Local Storm Reports -
Misc Statements -
Norman Soundings:
12z
and
00z 05/09/03
The Chase -
Team 1 - David Underwood,
Ray Hardy, and Putnam Reiter
Miles Driven - 320
Departure Time - 13:00 CDT
Return Time - 20:30 CDT
We left Oklahoma City around
13:00 CDT and headed north on I-35. We got to Highway 51 and went west
about one mile to Highway 77. We sat there for about two hours. The
sky was so hazy that we couldn't see more than 5 miles with surface features.
Anything towering about 10,000 feet became noticeable. We saw some towers
and became very encouraged.
Around 16:00 CDT we got word of
a storm near Lawton and one near Anadarko. We debated messing with the
Anadarko storm, though decided to sit fast since we knew this area was
favorable. About 16:30 CDT we got word that the Anadarko storm was
rotating as it moved near Tuttle. We decided to head south since it was
approaching the metro. We thought that there would be plenty of time to
intercept it near I-40 and Sooner Road since the storm was moving at about
30mph. We got to I-40 and I-35 to realize that there was heavy rain and
small hail. Seeing that traffic was pretty bad we exited near SE 15th.
About this time we realized
that the storm was moving a lot faster than 30mph, more like 45mph. We
decided to wait it out near SE 29th and I-40. We knew the tornado was way
south near I-240 and Sooner Road at this time. Seeing that the storm had
passed us by, we entered I-40 and continued east. As we got past Tinker
AFB we got a view of the storm and noticed the funnel. At this time it was
a tornado, but we couldn't see the surface contact. We exited Anderson
Road and turned north. We zigzagged a little on the section line roads of
eastern Oklahoma County. Eventually we zoomed north to I-44 and turned
northeast to catch the storm. The storm was moving so fast that by about
18:50 it was approaching Bristow. Seeing that there was no way to get a
good view and it looked HP, we decided to head home.
We turned around at Bristow and
head back southwest of I-44. After a brief stop at the Wellston McDonald's
we headed towards OKC, getting into town around 20:00 CDT.
Lessons Learned -
- Left our original
location too soon. However, it was difficult to stay there knowing that
OKC was being threatened. We picked a great spot and a storm did develop
very near our location. This storm went through Osage County, producing a
long track tornado.
- Storm motion was once again a problem here. The Oklahoma City
storm moved around 45-50mph much of its life. Many people, including the
NWS, reported it as 30mph. The proof is that this storm made it from I-35
and Shields Blvd to Bristow in 90 minutes, that's a fast moving storm.
Multimedia - (in these
clips you'll hear audio from KFOR-TV over 104.1MHz radio station in OKC).
- North of Tinker AFB and north
side of the storm.
Clip 1
- Exiting I-40 and turning north on Anderson Road, funnel from OKC tornado.
Clip 2
- Driving northeast on I-44 near
Chandler.
Clip 3
Encounters -
Engaged Storm: Yes - I-40
and Douglas Blvd
Tornado: Yes
Funnel: Yes
Hail (larger than 0.75 inches): Golfball
Wall Cloud: Yes
Wind (above 57.4 mph): No
