Area Forecast Discussion
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FXUS62 KTAE 021118
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
614 AM EST Mon Dec 2 2013
.NEAR TERM [Through Today]...
The 03 UTC regional surface analysis showed a very weak pressure
pattern across the Southeast, especially for late Autumn. Perhaps
the most prominent features were a an area of high pressure centered
over GA and AL, and a weak, quasi-stationary front across central
FL. Vapor imagery and upper air data showed fast, fairly zonal flow
over the CONUS, with a weak short wave trough over LA. There were
some areas of very light rain ahead of this trough, but the very dry
air below makes it unlikely that more than a few sprinkles will
reach the ground this morning.
This trough will exit east of our region by this afternoon, followed
by drying/subsidence aloft and end to any light rain/sprinkles.
However, there may still be some areas of lower layer clouds. High
temperatures will be in the upper 60s to lower 70s.
.SHORT TERM [Tonight Through Wednesday]...
At the start of the short term period, a weak warm frontal feature
will begin to lift northward through the forecast area from the
Gulf of Mexico. With winds expected to shift southerly as the
boundary moves inland, should see a favorable set up for advection
fog both tonight and especially on Tuesday night given the
relatively cool shelf waters (upper 50s to mid 60s) off the Florida
Panhandle and in Apalachee Bay.
The best chance for any notable precipitation with the warm front
should be on Tuesday afternoon as the boundary moves through
Southern Alabama and Southwestern Georgia. Local CAM guidance
seems to agree reasonably well with the NAM that the best forcing
for shower activity, albeit very light, is best focused across the
western portion of the forecast area. As weak as the boundary
appears in surface data this morning and in the model fields by
Tuesday afternoon, it appears the NAM-based MET pops are too high,
though the overall pattern looks good.
By Tuesday night, the boundary should be sufficiently far north of
the region that any forcing for precipitation should come to an
After the low cloudiness/fog mixes out on Wednesday, temperatures
should be unseasonably warm under partly cloudy skies. Much of the
area stands a good chance at seeing highs in the mid to upper 70s,
with the exception of areas right along the coast, where southerly
winds over cool shelf waters will keep max temps around 70. Inland
temperatures will be running around 10 degrees above normal, but
still below record highs for early December, which are generally
in the lower 80s.
.LONG TERM [Wednesday Night through Sunday]...
In the fast upper flow between the trough and the ridge, a PV
anomaly originating from a cutoff low in the Pacific will race
northeast, skimming the Southeast on Thursday. This will likely
result in some sort of surface troughing just to our northwest,
and eventually cyclogenesis as the anomaly passes over the
Appalachians. Thereafter, we will remain in-between the trough and
the ridge to round out the period.
All of this translates to the possibility of a rather unstable
period at the surface with a prolonged period of shower activity
across the Southeast along a quasi-stationary front, likely
enhanced by several surface waves. At this time the bulk of the
rain appears to stay just northwest of our immediate forecast area
but on-and-off rain through Sunday should be expected. The
Southeast will likely be sharply divided with the Tri-State area
sandwiched right in the middle of the unsettled weather to the
northwest, and unusually hot weather to the southeast. If the
forecast pattern holds true, then we`ll likely be dealing with
warmer than average temperatures through the period as a result of
the strong upper ridge. Expect afternoon highs to possibly reach
80 for most spots by the end of the week. Bottom line, expect a
mix of showers and warmer than average temperatures.
.AVIATION [through 12 UTC Tuesday]...
-- Changed Discussion --Abundant high clouds (around 25k ft), and even a few sprinkles, were
streaming over the region this morning, but these will partially
clear by afternoon. Patchy light fog will dissipate by mid morning.
VFR conditions and generally west winds around 5 KT will prevail
into tonight. There may be a better chance of fog/low clouds Tuesday
morning, but much will depend on how much rain develops around dawn
Tuesday. We will take another look at this in subsequent TAF
-- End Changed Discussion --
Winds will gradually shift to onshore but remain on the low side
for December through much of the week. An increase in winds and
seas is expected by Thursday night as the pressure gradient
tightens ahead of an approaching cold front. At this time,
headline conditions are not anticipated ahead of this front.
Red Flag conditions are not expected for the next several days.
With no significant rainfall anticipated through the week, no
notable rises are expected on the rivers. Rises from last week`s
rainfall has just about progressed through the lower portion of
the Choctawhatchee, Apalachicola, and Ochlockonee river systems
with crests having recently occurred at Bruce, Wewahitchka, and
Smith Creek, respectively in these basins.
.PRELIMINARY POINT TEMPS/POPS...
Tallahassee 71 52 72 56 76 / 0 10 20 10 10
Panama City 69 59 71 63 72 / 10 20 20 10 10
Dothan 69 53 74 58 77 / 10 10 30 10 10
Albany 68 50 72 57 76 / 10 10 20 10 10
Valdosta 69 47 72 55 77 / 0 10 10 10 10
Cross City 70 48 73 57 75 / 0 10 10 10 10
Apalachicola 68 58 70 63 70 / 10 10 20 10 10