Severe Weather Discussion for June 15 – 21, 2009.
– Active severe weather day is possible on Monday across the northwest
1/2 of Oklahoma. Slight chance of storms may exist Friday and Saturday.
– Temperatures will be in the low 90s Monday – Sunday.
– Severe Thunderstorms in Oklahoma: 35%
– Storm Chase: 40%
– Tropical Development: < 5%
Most exciting part of this forecast appears to be on Monday as strong
mid-level flow remains across Oklahoma. A shortwave trof will
translate eastward during the day and should combine with decent
instability to produce severe thunderstorms. A dryline is expected to
form in the Texas panhandle and surge east to at least the TX/OK
border. Storms are expected to develop late afternoon or early
evening along this feature and in the higher terrain of Colorado.
These storms should move east into Oklahoma during the evening hours.
Degree of instability and shear will support supercells. Models are
seemingly having trouble with CAPE values, especially the NAM. The
18z GFS seems to have gotten a clue. None of them develop precip
tomorrow but then again many didn't this afternoon either where a
tornado has been reported in NW Texas.
After Tuesday the 588dm ridge over Texas is expected to build into the
region. This should limit thunderstorm chances and warm things up a
little. I've tempered the warming some to the low 90s for now. This
is also playing the middle of the road as the models disagree on the
ridge axis much of the week. There is a chance the ridge may weaken
some Friday/Saturday as stronger mid-level flow moves across the
region. If so, then precip chances would return. I kept slight POPs
for this time period.
The group is looking to chase on Monday, current target is Shattuck to Gage.
This message was sent using IMP, the Internet Messaging Program.