Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Tallahassee Florida
1055 am EDT Wednesday Jul 1 2015
Near term [through today]...
The morning analysis depicts upper level troughing across the
eastern states with ridging across the west. The local airmass
remains moist and unstable with the 12z ktae sounding still
exhibiting relatively steep middle level lapse rates for this time of
year along with strong instability and above average shear for
Summer. However...unlike yesterday morning...there is no mesoscale convective system
barreling towards US from the west. It looks like the next main
upper level shortwave is still well back off to the northwest
across portions of southeast Missouri and west Tennessee.
Therefore...we are expecting less coverage of afternoon
thunderstorms compared to yesterday. Still though...given the
airmass in place across the area...we cannot rule out an isolated
strong to severe storm in the area this afternoon...but we are not
expecting the coverage of severe weather that we saw yesterday.
[through 12z thursday] VFR conditions will prevail today with
scattered afternoon thunderstorms.
Previous discussion [639 am edt]...
Short term [tonight through friday]...
A mean middle-upper level trough will remain over much of the eastern
conus, while the western periphery of the Bermuda surface ridge
continues across peninsular Florida. The latest nwp guidance is in good
agreement in bringing a short wave trough through the base of the
mean long wave trough on Thursday, with a good chance of rain for our
region. Probability of precipitation will generally be in the 50 to 70 percent range. The
guidance is not in quite as good agreement on Friday. Some of the
guidance suggest considerable drying of the middle-upper troposphere
behind thursday's short wave trough, while others do not show as
much drying. Our forecast pop is in the middle of these
possibilities, in the 30-40 percent range. Highs will be near 90
Thursday, then lower to middle 90s Friday. Lows will be in the 70s.
Relatively weak 500 mb flow (20 knots or less) suggest a lack of
significant storm organization, though an isolated pulse severe
storm is possible each afternoon.
Long term [friday night through wednesday]...
This doesn't happen in our area very often during the Summer, but
there are significant differences between the 00 UTC GFS and European model (ecmwf)
solutions. The GFS solution eventually pinches off the bottom of the
eastern Continental U.S. Trough into a cutoff low over our region, while the
European model (ecmwf) builds a 500 mb ridge over our area. The European model (ecmwf) solution
would favor hot temperatures with isolated mainly afternoon and
evening thunderstorms. The GFS would favor slightly cooler high
temperatures with scattered to numerous thunderstorms. Since it's
unclear which will be correct, we will take the average of the two
solutions, which yields near-climatology probability of precipitation and temperatures.
Light to moderate west-southwest winds are likely to continue
through Friday as the coastal waters remain north of the Bermuda
ridge. Winds will be at their strongest during the afternoon and
There are no red flag concerns as relative humidity will remain above critical
Rainfall amounts averaged from 0.50 to 1 inch across the forecast
area Tuesday, which may cause some brief rises on some of the
rivers. However, the mmefs keeps river stages below their local
action stages for the next several days. Based on our local ensemble
of cams, the probability of getting 6 inches of rain within 25 miles
of a point during a 12-hour period is 10 percent or less through
Preliminary point temps/pops...
Tallahassee 92 74 90 74 93 / 40 30 70 20 30
Panama City 86 78 87 79 87 / 40 30 30 20 30
Dothan 91 73 89 74 92 / 40 40 60 30 30
Albany 91 72 90 74 92 / 40 40 60 30 40
Valdosta 91 71 90 73 93 / 50 30 70 30 40
Cross City 92 74 91 74 92 / 30 20 40 20 30
Apalachicola 89 78 88 78 89 / 40 30 30 20 30