Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 250336
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1036 PM EST Tue Feb 24 2015
.Near Term [Through Tonight]...
Current fcst is basically well on track with mostly cloudy and
cool conditions dominating the region with a few patches of very
light rain falling across parts of the FL Panhandle and Big Bend
and especially over the northern Gulf of Mexico. As was the case
last night, did make some slight downward adjustments to temps
with values ranging from around 40 over most of SE AL and western
portions of the FL Panhandle (similar to last night as of 10 pm
EST), but unlike last night, the very cool and clammy air has
progressed further to the south and east. Tonight, temps have
already dropped into the upper 40s to the lower 50s over most
areas to the south and east of the Apalachicola River.
[Through 00Z Thursday] Yet another complex Taf fcst over the next
24 hrs, with generally MVFR to possibly IFR Cigs (esp. at VLD)
moving through from time to time underneath canopies of mid and
upper level VFR Cigs. Did go with some lower Vis at VLD and now
amended for ABY as their lower Cigs have dissipated for the time
being. On Wed., rain will be moving in from west to east across
the CWA with many Hi-Res WRF runs showing a fairly potent squall
line during the late afternoon and early evening hours. At this
time, have limited TSTMS to TLH and ECP.
.Prev Discussion [334 PM EST]...
.Short Term [Wednesday Through Thursday Night]...
Shortwave exiting the Desert Southwest will approach the Central
Gulf Coast on Wednesday with surface low pressure deepening over
the north central Gulf. Divergence aloft ahead of the upper
system coupled with very strong isentropic forcing ahead of the
surface low will lead to a large area of rain spreading over the
forecast area during the day on Wednesday. A good soaking rain is
in store for the region with rainfall totals generally in the 1.5
to 2.5 inch range. With the stationary frontal boundary nearly
bisecting the forecast area, temperatures will vary widely on
Wednesday, with highs ranging from the mid 40s in the northwest to
the lower 60s in the southeastern Big Bend.
Of mild concern is the very strong low level jet which is forecast
to precede the surface low. H85 winds will exceed 55 knots across
the Big Bend by late Wednesday, with 0-1km shear values exceeding
50 knots. Guidance also indicates that a small wedge of
instability may push onshore in the eastern Panhandle and Big Bend
late in the afternoon into the early evening. There may be just
enough instability to generate a few severe thunderstorms during
this period, with the best chance for damaging winds/isolated
tornado generally south of a line from Panama City to Tallahassee
The rain will exit to the east by late Wednesday night with
relatively weak high pressure building in for Thursday.
Temperatures will continue to be seasonably cool, with highs on
Thursday ranging from the mid 50s in the northwest to the mid 60s
in the southeast. Lows are forecast to remain above freezing
through Friday morning.
.Long Term [Friday Through Tuesday]...
For Friday into the weekend, a broad trough will be in place
across the eastern half of the country with strong high pressure
parked over the midwestern states. This sprawling high will keep
the weather seasonably cool across the forecast area. A lingering
stalled frontal boundary south of the region may wiggle back north
just enough on Saturday to introduce a few showers into the
southeastern half of the area. However, the next significant
chance of rain is not expected until Sunday or Monday when the
high breaks down and allows warmth and moisture to flow northward
Light offshore flow overnight will shift to southerly and increase
rapidly Wednesday afternoon, as low pressure approaches the waters
from the west. Winds and seas will reach small craft advisory
levels during the afternoon, with winds shifting to the northwest
and diminishing Wednesday night. High pressure north of the waters
will keep offshore flow in place through the end of the week, with
conditions occasionally reaching exercise caution or advisory
levels, especially as the weekend approaches.
A developing low pressure system will traverse the Gulf Coast on
Wednesday creating very high rain chances and Wet Flag conditions
across the Tri-state area. Thereafter, no fire weather problems
are expected for the remainder of the week as afternoon relative
humidities will remain well above Red Flag levels.
A coastal low pressure system tomorrow is forecast to produce a
widespread total of 1.5-2.5" of rain across the forecast area. No
flooding is forecast, however, these totals will cause rises along
our area rivers and bring several sites along the Kinchafoonee Creek
and the Choctawhatchee, Ochlockonee, Aucilla, and Upper
Withlacoochee Rivers into action stage. The Withlacoochee River at
Valdosta is likely to crest near minor flood stage by the end of the
week and could reach a higher and earlier peak if rainfall totals
end up being higher than currently forecast.
.Preliminary Point Temps/PoPs...
Tallahassee 46 56 46 58 39 / 20 100 90 10 10
Panama City 47 55 46 56 41 / 30 100 90 10 10
Dothan 40 48 36 54 36 / 20 100 80 10 10
Albany 41 50 38 55 36 / 20 100 90 10 10
Valdosta 45 57 47 58 41 / 20 100 100 10 10
Cross City 49 62 54 64 43 / 30 40 100 20 10
Apalachicola 50 59 47 58 43 / 30 80 90 10 10