Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 250133
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
933 PM EDT Thu Apr 24 2014
.Near Term [Through Tonight]...
The last few frames of visible satellite before sunset, and now
the 11-3.9 micron satellite loops show some low stratus expanding
inland over the Florida Panhandle coast. Most of this has remained
low stratus so far, with none of the observing sites reporting fog
of any significance yet. Model consensus expands this stratus
layer across the rest of our forecast area overnight, so the sky
grids were updated to show mostly cloudy to overcast skies by
later tonight. The big question is whether or not any fog can
develop, or the stratus layer lowers enough to produce some fog
where the boundary layer can decouple more. The SREF probabilities
suggest a 50-70% chance of less than 1 mile visibilities over much
of our forecast area by 12z Friday, while the NARRE near term
ensemble probabilities are quite a bit less. We felt there was
enough of a chance to warrant including fog everywhere in our
forecast area, with some patchy dense fog wording in some areas.
The increased cloud cover could keep temperatures a bit warmer
overnight, so the low temperatures were nudged up slightly.
[Through 00Z Saturday] Another round of IFR to LIFR level VIS and
CIGS is expected to develop at all of the terminals (except ABY
which is fcst to remain MVFR) tonight into Friday morning in the
moistening onshore flow. The most pessimistic fcst is ECP which may
drop to these low levels before midnight, then not lift and break
out until 11 AM Friday. Also, VFR conditions should return and
prevail for the remainder of the terminals by late morning, with
somewhat gusty W-SW winds for the afternoon as a weakening cold
front approaches from the west.
.Prev Discussion [305 PM EDT]...
.Short Term [Friday Through Saturday Night]...
A short wave will pass well north of the region on Friday as it
swings from the Ohio Valley to the Mid Atlantic. The associated cold
front will reach the northwestern part of the forecast area in the
afternoon and then become stationary between I-10 and the coast
Friday night. There will be little forcing for ascent over the
weakening boundary and PoPs were kept in the silent 10 category. The
front will begin lifting north again as a warm front on Saturday as
the yet another low pressure system deepens over the Great Plains.
Temps will generally be about 3-5 degrees above normal through the
.Long Term [Sunday Through Thursday]...
Upper level ridging is in place for the start of the period with a
surface high off to the east keeping the area dry. An upper level
low over the central plains will strengthen and become cutoff as it
moves slowly to the east. Moisture and instability will return to
the region Monday and the associated front will move through
Wednesday afternoon and evening. A low level jet will be over the
area with wind speeds up to 45 knots on Tuesday. GFS and Euro are
showing SBCAPE increasing to 1500-2000 J/kg. Deep layer shear will
increase to 35-40 kts over our far western zones with most of that
in the 0-1 km layer. Therefore, some storms could be strong to
marginally severe during the afternoon and evening hours Tuesday.
Storms will linger into Wednesday until frontal passage brings in
some drier air.
Onshore winds will generally be light with some enhancement near the
coast in the afternoon sea breeze. Winds will increase early next
week with cautionary conditions possible by Tuesday.
Minimum relative humidities will be in the 30s and 40s and will
not be low enough to reach red flag criteria. Dispersion values
will be in the 60s for most of the area tomorrow, decreasing to
the 30s for Saturday.
Most of our area rivers are above normal stage with many in flood
stage. The Choctawhatchee at Bruce is at major flood stage. Most
area rivers have already crested with the exception of the
Withlacoochee in Florida and the Suwannee River, where river levels
will continue to rise slowly for the remainder of the week. The next
chance for any significant rainfall is next Tuesday. At this time,
QPF values are low, around 0.75-1.25 inches.
The most up-to-date river forecast information can always be found
on our AHPS page (below).
.Preliminary Point Temps/PoPs...
Tallahassee 61 84 60 86 58 / 0 10 0 0 0
Panama City 64 78 63 80 64 / 0 10 10 0 10
Dothan 61 83 58 86 59 / 0 10 0 0 0
Albany 60 84 58 86 57 / 10 10 10 0 0
Valdosta 59 85 60 86 57 / 10 10 10 0 0
Cross City 60 83 60 84 58 / 0 10 10 0 10
Apalachicola 64 78 63 79 62 / 0 10 10 0 0