Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Norman OK
801 PM CDT Tuesday Sep 2 2014
VFR conditions are likely across the area over the next 24 hours.
NAM hints of the possibility of some MVFR ceilings overnight... but
right now that seems to be the only signal...so have kept VFR
conditions in the tafs but will continue to watch the model trends
Previous discussion... /issued 745 PM CDT Tuesday Sep 2 2014/
removed storm chances over western Oklahoma this evening
and confined them to far northern Oklahoma...north of an
Alva to Stillwater line tonight.
a few storms may develop in far northern Oklahoma after
9 PM this evening...though appears most storm development may
be north of the Oklahoma Kansas Stateline.
No storms formed late this afternoon/early evening across western
or northern Oklahoma...or anywhere in the weather forecast office Norman forecast
area. Very warm capping middle level temperatures and perhaps sinking
air behind this morning/S storm complex seem to be reasons for no
development. Think this cap will not be overcome in western
Oklahoma this evening...thus removed rain chances.
A few storms may develop on the nose of a developing low level in
the 9 to 11 PM time frame in far northern Oklahoma as recent hrrr
runs suggested. If they develop...they could be strong to
marginally severe with hail and wind the main hazards. Confidence
that these storms will develop appears to be moderate...though
confidence with exact timing and location remain low. Kept 20 to
30 percent chances in north of a Alva to Stillwater line.
Products have been updated.
Previous discussion... /issued 358 PM CDT Tuesday Sep 2 2014/
the showers and thunderstorms have finally ended across eastern OK
this afternoon. An outflow boundary extends from near Ardmore to
Geary...and is drifting westward. Although surface convergence will be
very limited along this boundary...some isolated redevelopment
cannot be ruled out later this afternoon and evening west of it
where the cap has eroded. This may be especially true across northwest/west
OK where surface flow is increasingly confluent. Additionally...most
of the guidance suggests a small area of showers and thunderstorms
developing later tonight across the NE along the lifting synoptic
By tomorrow afternoon...southerly surface flow will return to the
entire area as a Lee trough develops thanks to zonal middle level
flow over The Rockies. Highs will be around 5 degrees above average.
Very little will change for Thursday...although a vorticity maximum
currently seen northwest of Seattle in WV will make its way along the
US/Canada border to near northern ND by 12z. An accompanying cold
front will push south into northwest Kansas by late Thursday...but will likely
have any impact on our forecast area. This may not be the case by Friday
though as it continues south into northern OK. The European model (ecmwf) continues
to be the most aggressive with this front (1026 mb surface high by Friday
am over ne) pushing it all the way to the Red River by Sat am.
Feel like this is possible considering a slightly more amplified
pattern...but it appears a bit too aggressive so leaned closer to
the GFS for now. Probability of precipitation continue to appear more likely with this
front...but given timing discrepancies will avoid likely Cat for
now and stick with high chances.
Much more seasonable temperatures are expected behind this cold
front this weekend and through early next week. Some low 70s even
look possible for extreme northwest OK Saturday where the highest probability of precipitation
will likely reside. After frontal passage a slow warmup is
anticipated...but a pattern shift to a broad trough over the
northern Continental U.S. Will likely keep temperatures around average at least.
Preliminary point temps/pops...
Oklahoma City OK 75 95 75 95 / 0 0 0 0
Hobart OK 75 97 76 96 / 0 0 0 0
Wichita Falls Texas 78 98 76 98 / 0 0 0 0
gage OK 73 97 74 96 / 10 10 0 0
Ponca City OK 74 94 78 95 / 30 0 0 0
Durant OK 75 95 75 95 / 0 0 0 0