509
FXUS62 KTAE 182356
AFDTAE

Area Forecast Discussion
National Weather Service Tallahassee FL
756 PM EDT Sat May 18 2024

...New AVIATION...

.NEAR TERM...
(Through Sunday)
Issued at 316 PM EDT Sat May 18 2024

In the big picture, we are watching an upper low over northeast
Mississippi, and a positively tilted upper trough trailing back
across Louisiana. Over the next 24 hours, these features will move
east.

For now, the active jet stream equatorward of the positive tilt
trough has been fanning and organizing our convection today. The
convection has become outflow-driven and is moving into a region
with less impressive upper level support. Basically, our most recent
round of severe storms and flash flooding will continue to diminish
as we head into the evening.

On Sunday, colder air aloft within the passing upper trough will
steepen low-mid level lapse rates. This will contribute to afternoon
shower and thunderstorm development, with some of the better
coverage coming under the coldest air aloft in our Georgia counties,
and then where we get seabreeze convergence over our Florida
counties. With cold air aloft and 500 mb temperatures as low as -11C
to -12C, small hail will be a stronger possibility. Steep lapse
rates and unidirectional speed shear will support gusty outflow
winds.

&&

.SHORT TERM...
(Sunday night through Wednesday)
Issued at 316 PM EDT Sat May 18 2024

Additional shortwave energy rotates through the northwest flow
aloft on Monday, and with PWATs around 1.2 inches and added
convergence from the seabreeze, some afternoon showers possible
invof the I-10 corridor (especially the eastern FL Big Bend)
but do not expect thunder.

Deep layer ridging builds in thereafter through Wednesday
with low to mid-level northeast flow and a dry air mass.

With rising heights aloft, highs gradually warm from the
low-mid 80s on Monday to the upper 80s-lower 90s Wednesday.

&&

.LONG TERM...
(Wednesday night through Friday)
Issued at 316 PM EDT Sat May 18 2024

Deep layer ridging moves southeast of the region with low
to mid-level southerly flow getting underway. Cannot rule
out a pop-up shower or thunderstorm with the seabreeze on
Thursday. Otherwise, the better chance of a shower/t-storm
is on Friday with the approach of a shortwave aloft. Highs
generally remaining in the upper 80s-lower 90s through the
period.

&&

.AVIATION...
(00Z TAFS)
Issued at 755 PM EDT Sat May 18 2024

The bulk of earlier thunderstorms have moved on, so just a few
light showers in the vicinity of TLH and VLD over the next few
hours. The latest HRRR does develop TS about 10-30 miles south of
VLD later this evening, before it exits to the east, so have
included a short period of VCTS there. Otherwise, the moist low-
level air mass will lend itself to overnight development of MVFR
stratus, which will then lower to IFR stratus by sunrise. In
typical fashion, it will lift starting 2-3 hours after sunrise.

An upper low will move across north Georgia on Sunday. The cold
air aloft will support some pop-up afternoon shower and
thunderstorm development. Confidence in placement, coverage, and
timing is only high enough go with VCSH and VCTS at this time.

&&

.MARINE...
Issued at 316 PM EDT Sat May 18 2024

Showers and thunderstorms will continue to move across the waters
through tonight with the potential for strong to severe wind gusts.
Meanwhile, a weak front will stall across the waters through Sunday,
with renewed chances of showers and thunderstorms. High pressure
will setup anchor northeast of the coastal waters by Monday and
remain there through at least midweek.

&&

.FIRE WEATHER...
Issued at 316 PM EDT Sat May 18 2024

A weak cold front will pass the districts late tonight, bringing a
turn to westerly breezes and a somewhat drier air mass. A few
afternoon pop-up showers and thunderstorms are possible on Sunday
afternoon. Then high pressure will bridge in from the northeast on
Sunday night, bringing a turn to northeast breezes on Monday along
with a little more drying of the air mas. A deeply mixed layer on
Tuesday afternoon will be the main contributor to high dispersion
values over inland districts. This could lead to well-developed
vertical smoke columns.

&&

.HYDROLOGY...
Issued at 316 PM EDT Sat May 18 2024

The highest rainfall amounts have occurred from Geneva County to
invof the I-10 corridor in the FL counties with radar estimated in
the 3-6 inch, and another bullseye of 6-8 inches near southern
Jefferson County. Much of the remainder of Southeast AL & Southwest
GA (outside of the southern tier of counties) is in the 2-4 inch
range.

The Flash Flood Watch is gradually being cancelled from northwest
to southeast as the heavier rainfall abates late Saturday afternoon.
Additional rainfall of between a half of an inch and one inch is
expected from the I-75 corridor of GA into the FL Big Bend through
Sunday.

The Withlacoochee River at Valdosta (Skipper Bridge Road) and
Quitman, Ochlockonee River at Concord, and Saint Marks River at
Newport are all in minor flood, with the Saint Marks expected
to crest just below moderate by Sunday evening. Meanwhile, some
points along the Choctawhatchee, Chipola, Flint, and Aucilla
Rivers are in -or- will reach action stage. The Shoal River at
Mossy Head is also headed toward action stage as of late Saturday
afternoon. Addt`l river flooding is possible as water continues
to drain into the aforementioned basins.

Beyond Sunday, several days of dry weather is expected.

&&

.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   68  87  68  86 /  40  40   0  20
Panama City   70  85  69  86 /  30  10   0  10
Dothan        67  84  66  84 /  20  20   0  10
Albany        67  84  65  84 /  30  50   0  10
Valdosta      68  86  67  85 /  50  40  10  20
Cross City    69  86  67  87 /  70  60  10  40
Apalachicola  71  84  70  83 /  40  20   0  10

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through late Sunday night for FLZ108-112-
     114-115.

GA...None.
AL...None.
GM...Small Craft Advisory until 1 AM EDT /midnight CDT/ Sunday for
     GMZ730-750-752-755-765-770-772-775.

&&

$$

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