126
FXUS62 KTAE 041030
AFDTAE

Area Forecast Discussion
National Weather Service Tallahassee FL
630 AM EDT Fri Jul 4 2025

...New AVIATION...

.NEAR TERM...
(Today and tonight)
Issued at 236 AM EDT Fri Jul 4 2025

A broad area of low pressure centered near the northern FL Peninsula
will drive our weather today. Patchy to areas of fog this morning
from the I-75 corridor of GA into the eastern FL Big Bend should
dissipate around 8 AM ET. Locally dense fog is possible. Attention
then turns to the development of showers and thunderstorms.

The mean 1000-700 hPa flow is northeast at 10-15 kts due to the
aforementioned low. This will pin the Gulf seabreeze closer to the
coast favoring convection south of I-10, except closer to the I-75
corridor where the Atlantic seabreeze will also favor convection,
but to lesser extent. In addition, a westward translating shortwave
rotating around the low will lead to another area of convection
extending north of the Apalachicola National Forest into Southeast
AL. PoP forecast leans more heavily toward a consensus of the short
term guidance, which has a better handle on the above details, with
values along lower envelope of the guidance. This results in an axis
of 30-50% PoP from the Apalachicola River northward into Southeast
AL, with another bullseye of 40-60% PoP in the Southeast FL Big
Bend. The driest area today will be as you move northeast through
the GA counties in the wake of the aforementioned shortwave. Also,
there is a strong signal in the guidance for additional convection
to develop in the FL Big Bend around 00Z, possibly favoring the
Tallahassee area, as the Atlantic seabreeze interacts w/residual
outflow boundaries.

The main concern with storms today will be heavy rainfall and gusty
winds. In particular, poor drainage flooding is possible, mainly in
the Southeast FL Big Bend and closer to the Apalachicola River as
storms propagate slowly southward within weak steering flow aloft.
Soundings also indicate steeper mid-level lapse rates compared to
yesterday, with DCAPE in excess of 1k J/kg, and the characteristic
inverted-v/caret profile. As a result, cannot rule out isolated
damaging winds from a pulse-type severe thunderstorm. Activity will
dissipate shortly after sunset.

Given PoPs on the lower envelope of the guidance today, trended
toward the 75th percentile for highs, generally in the mid-90s.
But the tendency to mix drier air aloft down to the surface in
the afternoon and evening should limit heat indices to around
100F. Trended the dew points closer to some of the MOS/hi-res
guidance, with values dropping into the mid-60s over portions of
Southwest GA and perhaps Walton Co. area by this evening, with
upper 60s to lower 70s elsewhere away from the coast.

&&

.SHORT TERM...
(Saturday through Sunday night)
Issued at 146 AM EDT Fri Jul 4 2025

A low pressure center, perhaps a tropical or subtropical cyclone,
will be located off the Georgia coast on Saturday. No tropical
impacts will be felt over the Tallahassee service area.

Northwest of the low center, a swath of moderate northeast flow will
overspread the Georgia coastal plain. Deeper moisture and higher PW
values will have wrapped inland from that Atlantic in this flow,
pushing PW values in excess of 2 inches across our south-central
Georgia and FL Big Bend counties. GEFS plume diagrams show that our
Eastern Time Zone counties will have their moistest PW values of the
next 7 days on Saturday. The air will remain drier off to the
northwest, i.e. across Southeast Alabama and the Chattahoochee
Valley. Speed convergence at the front edge or nose of the moderate
northeasterlies will provide much of the lift for showers and
thunderstorms, with higher PoPs further southeast in the deeper
moisture. Closer to the coast, a pinned seabreeze will add even more
lift. Storms will be capable of gusty winds due to the faster storm
motion. Near the moisture gradient, dry-air entrainment will also
enhance the gustiness of storms.

On Sunday, a low pressure trough extending west out of the low
center will lift north across the region, as the main low lifts
north or northeast closer to South Carolina. This evolution will cut
off and end the faster northeast flow. So we will be more reliant on
broad-scale and ill-defined troughing, at the surface and aloft,
as well as a seabreeze front that will have greater inland extent
without the headwind of northeast flow.

&&

.LONG TERM...
(Monday through Thursday)
Issued at 146 AM EDT Fri Jul 4 2025

A subtropical 500 mb ridge axis will expand westward north of the
Bahamas and across central/north FL on Monday. The ridge axis will
extend directly across our region on Tuesday and Wednesday, with 500
mb heights running in the 5910-5940 meter range. Fairly high heights
and warmer air aloft will add an element of convective inhibition,
and high pressure aloft will bring some larger scale subsidence. PW
values in the 1.6-1.9 inch range will still be adequately high
for deep, moist convection, but convection will rely more heavily
on common mesoscale forcing such as the seabreeze front. Daily
rain chances will therefore reach their 7-day lows around next
Tuesday. With warmer air aloft, more sunshine, and less cooling
rain, Monday through Wednesday will feature the hottest
temperatures of the next 7 days, with mid 90s looking very common.

By next Thursday, some longwave trough amplification should take
place extending south from the Great Lakes. This is a common
downstream response to strengthening of the climatological
summertime Four Corners high over the Southwest U.S.. This trough
amplification will be enough to budge our 500 mb ridge southward
down the FL Peninsula. Our service area will experience modest
upper height falls, and we will come under weak westerly flow
aloft. This will be enough for an upward trend in rain chances for
next Thursday.

&&

.AVIATION...
(12Z TAFS)
Issued at 630 AM EDT Fri Jul 4 2025

MVFR in fog/low clouds at VLD around sunrise this morning with a
low probability of IFR. For today, a PROB30 was appropriate for
aftn TSRA at all but ABY during the afternoon and evening hours.

&&

.MARINE...
Issued at 146 AM EDT Fri Jul 4 2025

A slowly strengthening low pressure center off the Georgia and
South Carolina coasts will support gentle northwest breezes today,
peaking as a moderate northeast breeze on Saturday morning. A weak
low pressure trough will lift northward across the waters on
Sunday, and the subtropical high pressure ridge axis will then
build and sharpen from the Bahamas to the Middle Gulf on Monday
and Tuesday. On its northern periphery, the waters will experience
gentle to occasionally moderate southwest and west breezes.

&&

.FIRE WEATHER...
Issued at 146 AM EDT Fri Jul 4 2025

Much of the wetting rains this afternoon will focus in the
Florida Counties into Southeast Alabama, then expanding across
much of the region on Saturday. The main concern will be high
dispersion this afternoon in Southwest Georgia and on Saturday
across much of the region. Otherwise, thunderstorms may produce
brief erratic and gusty winds.

Patchy fog is likely this morning from the I-75 corridor of GA
into the eastern FL Big Bend, where it may be locally dense.

&&

.HYDROLOGY...
Issued at 146 AM EDT Fri Jul 4 2025

Hydrology concerns over the next 7 days will follow a common
summer theme. Summer thunderstorms --- mainly the afternoon and
evening variety --- will come with locally intense rainfall rates
beneath the core of stronger storms. The rainfall rates will lead
to localized runoff issues, especially in urban and poor drainage
areas.

River flooding is NOT expected for the next 7 days.

&&

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.

&&

.PRELIMINARY POINT TEMPS/POPS...
Tallahassee   95  74  91  73 /  30  40  80  20
Panama City   94  75  93  75 /  40  20  60  40
Dothan        95  73  92  73 /  30  20  40  10
Albany        95  73  91  72 /  20  10  40  10
Valdosta      95  73  90  73 /  30  20  70  20
Cross City    94  72  90  72 /  60  50  90  40
Apalachicola  90  75  88  75 /  40  30  80  60

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&

$$

NEAR TERM...LF
SHORT TERM...Haner
LONG TERM....Haner
AVIATION...LF
MARINE...Haner
FIRE WEATHER...LF
HYDROLOGY...Haner