Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 232102
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
402 PM EST Fri Jan 23 2015
...Heavy Rain and Marginal Threat for Severe Weather Now Limited to
the Southeast Florida Big Bend...
.Near Term [Through Tonight]...
At upper levels, a positively-tilted trough was approaching the
Lower Mississippi Valley this afternoon with diffluent flow aloft
out ahead of it across the Southeast. Surface analysis shows low
pressure centered over the western FL Panhandle with a warm front
extending northeastward from it into South GA. Much of the region
has already seen heavy rain today with 2.5-4 inch totals common
south of I-10. A few spots across the coastal counties received in
excess of 5 inches. While a few flooding reports have been received,
the heaviest rain has moved east of the flash flood watch area. We
therefore have cancelled the watch. Southeast portions of the FL Big
Bend are still in the heavy rain band, but are only expected to see
storm totals in the 2-3 inch range. This should not be sufficient to
produce flash flooding. Ponding of water on roadways and poor
drainage areas is a more likely scenario. Severe storms have thus
far remained offshore in the form of isolated supercells. It is
likely that several of these produced tornadic waterspouts, but in
all cases the circulation weakened before making it ashore. There is
still a marginal risk for severe storms coming in off the Gulf of
Mexico into Dixie County.
The low will lift north of the forecast area this evening and then
reform along the NC coast overnight pulling a cold front through the
area. Some light rain could linger behind the front until the short
wave passes and cuts off QG forcing for ascent. PoPs after midnight
will lower to likely east of an Albany to Tallahassee line with
chance PoPs west of there. Lows by dawn Saturday will range from the
lower 40s across the northwest half of the forecast area to the
lower 50s south and east of Perry.
.Short Term [Saturday Through Sunday Night]...
Wrap around moisture from a departing low will be lingering Saturday
morning. Rain chances will be very low by this time and cloud cover
will move out by Saturday afternoon. Winds will be gusty Saturday
morning and afternoon as a tight pressure gradient moves over the
area. Northwesterly flow will bring cooler, drier air on Saturday
with highs in the mid to upper 50s. On Sunday, a low over the Ohio
River Valley will track southeast towards North Carolina bringing a
weak cold front through the CWA. Rain and clouds are not expected
with this front, but there will be cooler, drier air once again
after FROPA on Monday morning. Highs Sunday will be in the low 60s.
Lows will be in the mid 30s Saturday night and low 40s on Sunday
.Long Term [Monday Through Friday]...
A deep upper level trough will remain over the Atlantic Coast of
Florida until mid week. High pressure at the sfc will move in by
Wednesday. Flow will be northerly and cool, dry air will remain in
place for most of the week. Another weak cold front will move
through Thursday night into Friday morning, bringing only a slight
chance of rain. Temperatures will be seasonal with highs generally
in the upper 50s and lower 60s. Lows will be in the mid to upper
[Through 18Z Saturday] A dynamic frontal system moving through
the area will yield widespread IFR-LIFR cigs throughout the
remainder of the day. Rain is mostly over for all terminals except
VLD. Southwesterly winds ahead of a cold front will progressively
veer to the northwest as it moves through the area. The timing of
this shift places it at DHN and ECP around 23/00Z, ABY around 01Z,
TLH around 03Z, and VLD around 06/07Z. Cigs will be slow to lift
behind the front (most terminals staying at least IFR until 10Z
tomorrow. By 18Z tomorrow, all terminals should be at least MVFR
with improving conditions. The exception is VLD where IFR could
persist through 18Z.
Gale Force winds are no longer expected over the marine area.
However, a Small Craft Advisory remains in effect until tomorrow
evening. A cold front will move through this evening, bringing
strong northwesterly winds behind it. Moderate southerly winds this
evening will increase and shift to westerly overnight. By morning,
winds will be strong and northwesterly. Sustained winds will reach
25 knots over the outer waters with brief gusts up to 35 knots
possible. Winds will become light to moderate Saturday night, only
to pick up again Sunday night and Monday. Small Craft Advisory
conditions are likely again Sunday night and Monday.
Heavy rainfall today will limit fire weather concerns for the next
several days, despite the arrival of drier air over the weekend.
A widespread 1.5-3" of rain fell across the area today, with
streaks of 3-6" roughly from Apalachicola to Madison. This has
caused sharp rises along some of our area rivers. Minor flooding
is forecast along the Withlacoochee and Aucilla rivers and is also
possible along the Shoal river today. Within the next week, more
minor flooding will be possible along the St. Marks, Ochlockonee,
and Kinchafoonee rivers, where rises are forecast to be slower.
.Preliminary Point Temps/PoPs...
Tallahassee 48 58 34 64 44 / 80 10 0 0 10
Panama City 46 56 40 63 49 / 60 10 0 0 10
Dothan 42 54 35 62 42 / 60 10 0 0 10
Albany 44 55 34 62 41 / 80 10 0 10 10
Valdosta 49 58 35 63 44 / 90 10 0 10 10
Cross City 53 61 35 64 46 / 90 20 10 0 10
Apalachicola 49 58 41 61 50 / 80 10 0 0 10
FL...RIP CURRENT RISK through late tonight for Coastal Bay-Coastal
Franklin-Coastal Gulf-South Walton.
GM...Small Craft Advisory until 7 PM EST Saturday for Apalachee Bay-
Coastal waters From Ochlockonee River to Apalachicola FL
out to 20 NM-Coastal waters from Suwannee River to Keaton
Beach FL out 20 NM-Coastal waters from Apalachicola to
Destin FL out 20 NM-Waters from Suwannee River to
Apalachicola FL from 20 to 60 NM.
Small Craft Advisory from 7 PM this evening to 7 PM EST Saturday
for Waters from Apalachicola to Destin FL from 20 to 60 NM.
Gale Warning until 7 PM EST this evening for Waters from
Apalachicola to Destin FL from 20 to 60 NM.