NEAR TERM [Through Rest of Tonight]...
The large scale progressive pattern is marked this mid evening by
deep layer ridging over SE region and deepening trough over Srn
Increasing cirrus clouds moving ahead of progressive upper low/ weak shortwave moving Ewd in the Gulf of Mex.
At surface, elongated 1029mb high moving Ewd along NC/SC coast with ridge Wwd to Nrn GA and Ewd into Wrn Atlc. Locally this translates to veering low level flow to onshore then WLY flow above H6 but still only about one-half inch PWAT.
During the overnight hours, expect mid and mainly high level moisture / cloud cover to increase from the SW to the NE as upper Gulf low advances towards our forecast area, and also from SE to NW at low levels as high moves further Ewd into Atlc. This reflected in area soundings i.e. RAP13 with PWATS increasing to around one inch by sunrise.
There may be enough upper level energy to produce some light rain after midnight, but it will likely remain in our Wrn offshore waters.
Added clouds and moisture means min temps should be noticeably milder than 24hrs ago, from mid 40s N to low 50s S. There may be enough upper level energy to produce some light rain after midnight, but it will likely remain in our Wrn offshore waters. Will go with NE-SW POP gradient, 0% (S/Cntrl GA/Big Bend) to 30% (offshore Wrn Waters).
SHORT TERM [Friday through Sunday]...
A weak low pressure system will develop in the central Gulf of
Mexico Friday morning ahead of a fast-approaching short wave trough
(currently over the Southern Plains).
The weak surface low will translate quickly eastward across the FL Peninsula Friday night and Saturday. The GFS and ECMWF continue to keep our forecast area on the northern periphery of the main QPF maximum in the northeast Gulf of Mexico, so our QPF will likely be less than a quarter of an inch at the coast, and a tenth of an inch or less inland. The NAM and ECMWF MOS hold on to above-average PoPs Friday night and Saturday while the GFS MOS forecasts considerable drying. We leaned more toward this drier scenario given the developing dry air aloft and minimal Q-G forcing shown in both models.
Rain chances will increase Sunday as a cold front approaches from the northwest. Except for relatively cool temperatures Friday afternoon (mid to upper 60s- because of the clouds), temperatures will be back above average.
LONG TERM [Sunday night through next Thursday]...
The GFS and ECMWF solutions were fairly similar, bringing a cold
front through our forecast area Sunday night and Monday, followed by
a cool & dry airmass.
The vertical motion field from the GFS show a weakening trend as the front traverses our area, and the best height falls will be well to our north.
So while our PoP will be high (50-70% range), the threat of severe storms appears low due to poor CAPE, marginal winds speeds aloft, and lackluster Q-G forcing.
The remainder of the period will be fair weather. Highs will be near
average (upper 60s north to lower to mid 70s south). Lows will be in
Upper and middle level clouds will stream across the area from the
southwest through the TAF.
MVFR ceilings will likely form nearer to dawn in moist easterly flow at KVLD and KABY.
Elsewhere MVFR conditions will be possible late tonight, into the morning at KECP where heavier rain is expected.
Tomorrow afternoon will likely feature VFR conditions under a solid mid-level cloud deck, with on and off light rain, especially at KECP and KTLH.
Winds and seas in mainly our well offshore Ern waters will remain at
borderline advisory levels until around 1 AM EST.
The pressure gradient will remain rather tight through Saturday as a weak low pressure system develops and moves quickly east across the eastern Gulf of Mexico.
E-SE winds will veer to the south on Sunday ahead of an approaching cold front.
Due to increase in relative humidity values over the next couple of
days, there are no fire weather concerns.
The combination of the Friday and Sunday/Monday rain events will
produce rainfall totals of an inch or less. With 3-hour Flash Flood
Guidance values of around 4 inches, flash flooding and/or river
flooding do not appear to be a concern.
PRELIMINARY POINT TEMPS/POPS...
Tallahassee 51 67 59 73 65 / 10 50 20 10 10
Panama City 54 68 60 73 66 / 20 60 20 10 10
Dothan 48 65 54 73 62 / 10 40 10 10 10
Albany 45 66 54 73 62 / 10 20 10 10 10
Valdosta 47 67 57 72 63 / 10 30 20 20 10
Cross City 52 72 61 74 65 / 10 50 40 40 20
Apalachicola 57 69 62 73 68 / 20 60 30 20 10
GM...SMALL CRAFT ADVISORY until 1 AM EST Friday for Waters from
Suwannee River to Apalachicola FL from 20 to 60 NM-Waters from Apalachicola to Destin FL from 20 to 60 NM.