June 7, 2007
Storm Chase
Central Oklahoma
Editor: Putnam E. Reiter
Forecast/Setup -
Risk Area: Enhanced Moderate Risk
Initial Target Area: Oklahoma City, Oklahoma
What a strange year storm wise. Much
of the activity as been in the Texas/Oklahoma panhandles with a little bit in
western Oklahoma. This event looked to be much closer to home and
certainly made us happy.
The general setup was for a longwave trof
to develop in the western U.S. and move east on the 6th. This trof would
reach the central plains on the 7th. Severe weather was expected both
days. Seasonable moisture was progged to be in-place by late afternoon on
the 6th and especially on the 7th. Instability parameters were quite
favorable given strong daytime heating and deep layer moisture.
The other component that had to be dealt with was
the cap (elevated mixed layer). All models progged a very strong cap
across the region on the 6th and kept the area dry. Initially the 6th
looked interested but it certainly appeared the cap would win and keep storms
from developing. The 7th looked like a better chance since the cap would
weaken given the location of the upper system. Winds would remain strong
and veer with height.
Early in the morning on the 7th the dryline got a
quick start moving east. Additionally, the winds veered statewide to the
south-southwest. Locations near and behind the dryline veered more
southwesterly, and had dewpoints in the 40s. The dryline reach central
Oklahoma by mid-afternoon an stalled. This feature was expected to be the
primary storm initiator during the afternoon as the cold front remained in
Kansas.
By early evening storms had not developed.
Surface analyses indicated that CAPE values were above 4500 J/Kg with little
convective inhibition. One problem was that winds were still veered across
the region but some areas had backed to southerly. A storm developed in
northwest Texas near Wichita Falls. Another area developed in Osage
County. These two areas were the only dryline storms of the day in
Oklahoma. The winds remained too veered for sustained development along
the dryline. As the sun set, development ceased.
A few severe thunderstorm warnings were
issued for this activity, but the main stuff came when the cold front moved into
the state overnight. Over all this was not the event we forecasted or
expected. The cap and veered flow ended up keeping storms limited.
Even the activity that formed wasn't all that impressive. The activity in
Osage County did get a tornado warning as it moved east, but a tornado was not
confirmed.
SPC Products:
SWO
Day 1
Graphics:
Risk Area
-
Tornado
Prob -
Damaging Wind Prob -
Hail Prob -
Storm Plot
- LSRs
Sounding:
00z OUN
GFS 00z Initialization:
Surface Pressure
- Dewpoints -
CAPE
- CIN -
Surface Temperature
- 850mb
Temperatures -
850mb Dewpoints
- 850mb Wind -
850mb Relative Humidity
- 700mb Wind
- 700mb
Temperatures -
700mb Relative Humidity
- 500mb Wind
-
500mb Relative Humidify
- 500mb Vorticity
-
400mb Wind -
300mb Wind
-
250mb Wind
- 250mb Relative
Humidity -
200mb Wind
Hook-Echo Discussions for this event.
SPC Case Review
The Chase -
Team 1 - Andy
Wallace, Rob Ferguson, and Putnam Reiter
Miles Driven - 80
Departure Time - 16:00 CDT
Return Time - 20:30 CDT
We left Oklahoma City and headed south on Western Ave. to
Norman. We saw a nice convergence area to our southwest and wanted
to watch it. This was confirmed via RADAR and surface analysis.
RADAR indicated two boundaries intersecting in this area. This was ahead
of the dryline about 30 miles, but had sustained vertical growth.
We got to Norman and went west on HWY 9 through Blanchard.
We then turned east on HWY 74B and drove a few mile east. We stopped and
watched the development for a while. This area really tried, but was
struggling. Eventually a sustained area moved away, but did not develop.
Around 6:30pm we decided to follow another enhanced area to see what it would
do. We drove on east to HWY 74 and then went north to I-35. We drove
north into Oklahoma City following this enhanced area. RADAR did not show
any development, other than that in Texas and northern Oklahoma.
We turned east on NE 23rd Street for a few miles as we watched
this area, however it became glaciated and we figured it was over. There
was no additional development and sunset was only 90 minutes away. We
headed back and got some dinner.
Lessons
Learned -
- I really cannot complain about the forecasting or
how we approached this event. Chase days can end up capped and it is
all part of the game. It has been a long time since we've failed to
see a storm, but it happens.
Multimedia
-
- No pictures or video.
Oklahoma City RADAR - 700kbEncounters
-
Engaged
Storm: None
Tornado: No
Funnel: No
Hail (larger than 0.75 inches): No.
Wall Cloud: No
Wind (above 57.4 mph): No
