Area Forecast Discussion
Issued by NWS
FXUS62 KTAE 202024
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TALLAHASSEE FL
324 PM EST Tue Jan 20 2015
.Near Term [Through Tonight]...
A shortwave moving through the northeast Gulf overnight generated an
extensive upper-level cloud deck over the entire state of Florida,
with scattered showers across south Florida along a resultant
surface trough. A much more subtle shortwave has been able to
generate another area of low pressure over the far western panhandle
of Florida. Two weak surface troughs are noted extending east and
south from this area of low pressure, and will be the focus for
light to moderate rain overnight.
As the aforementioned area of surface low pressure moves east
overnight, some weak isentropic ascent over the east-west oriented
trough could result in a few very light showers across the Tri-State
region. The higher probability for rain will be along the
north-south oriented trough where greater convergence exists due
simply to the motion of the system. This could bring some slightly
heavier and more widespread shower activity to areas south of
interstate 10 in north Florida. QPF amounts should remain below a
quarter of an inch in this region, and possibly only a trace
elsewhere. Due to the extensive cloud cover and rain chances
forecast, expect lows to barely dip into the 40s area-wide, with
middle 50s expected along the immediate panhandle coast.
.Short Term [Wednesday Through Thursday Night]...
Zonal flow will be in place at the start of the period. An inverted
surface trough will be in place just south of the forecast area and
could touch off some isolated showers Wednesday morning. The balance
of the day will be dry and mild with highs within a couple of
degrees either side of 70. This pattern will hold Wednesday night
with mild rain-free conditions and lows 8-10 degrees above normal.
By Thursday, cyclogenesis will occur off the South Texas coast in
response to an upper trough deepening over the Southern Plains. As
this low tracks across the northern Gulf of Mexico, frontogenetic
forcing will increase across the forecast area. Slight chance PoPs
in the afternoon for our western zones will transition to likely for
much of the forecast area by dawn Friday.
.Long Term [Friday Through Tuesday]...
Most models bring the gulf low northeast across the forecast area
Friday afternoon and evening. PoPs will be categorical. We could
easily see 2-3 inches of rain from this system. However, thunder
will be restricted to our southeastern zones closer to the low level
instability. As the low moves off the Carolina Coast, drier and
cooler air will arrive in its wake for the weekend. A clipper system
will then dive southeast across the Carolinas on Monday, possibly
bringing some isolated showers to the northeast gulf region.
[Through 18Z Wednesday] A scattered VFR CU field will gradually
fill in and lower from west to east through the remainder of the
afternoon and overnight. All terminals are expected to fall under
high-end MVFR ceiling restrictions overnight, with light rain
possible. Ceilings will begin to clear from west to east around
daybreak tomorrow, with all sites returning to VFR sometime
Winds will be light but shifting through the night as a trough moves
east across the waters. East to northeast winds will increase to
cautionary levels Thursday night. Expect more shifting winds on
Friday as low pressure moves northeast across the marine area. As
the low pulls northeast of the area, northwest winds in its wake
will increase to advisory levels behind it for Friday night and
Moisture levels will slowly increase throughout the week as a storm
system approaches the region on Thursday night into Friday. After
widespread rain across the region on Friday, drier air will begin to
arrive late Saturday. With cooler temperatures expected late in the
weekend, red flag conditions are not expected.
All area rivers are below flood stage and either steady or falling.
A low pressure system could bring widespread 2-3 inch rainfall
totals from Thursday night into Saturday morning. This would cause
rises on area rivers.
.Preliminary Point Temps/PoPs...
Tallahassee 48 71 50 68 55 / 40 10 0 10 60
Panama City 53 67 52 64 55 / 50 10 0 20 70
Dothan 48 67 46 62 50 / 20 0 0 20 70
Albany 46 68 45 62 50 / 10 10 0 10 60
Valdosta 47 69 47 67 54 / 10 10 0 10 50
Cross City 49 72 50 72 56 / 30 10 0 10 40
Apalachicola 53 69 54 67 58 / 60 10 0 20 60