745
FXUS62 KTAE 171603
AFDTAE

Area Forecast Discussion
National Weather Service Tallahassee FL
1203 PM EDT Fri May 17 2024

...New NEAR TERM...

.NEAR TERM...
(Through Saturday)
Issued at 1202 PM EDT Fri May 17 2024

The main concern through Saturday will be severe thunderstorms
and heavy rain.

In the big picture, a positively tilted southern stream upper
trough has moved east to Texas, ramping up west-southwesterly jet
stream winds along the northern Gulf Coast. A turn to southerly
low-level flow has brought a return of low-level moisture as a
warm front tries to creep northward and inland.

Earlier this morning, a leading MCS raced east across the
northeast Gulf, with the southern tip of the Forgotten Coast near
Apalachicola getting severe thunderstorm winds, with a measured
gust to 84 mph near the Cape in Gulf County. This MCS has now
exited off to the east, with a temporarily rain-stabilized air
mass over most of the forecast area late this morning. However,
fully sunny skies over the eastern Panhandle should allow mid-day
mid-May sunshine to quickly destabilize the air mass once more.

Already, a broken east-west band of thunderstorms is ongoing
across the southern half of Alabama into west-central Georgia. It
should take on a more positive tilt this afternoon and start to
slowly move southeast through this evening, affecting most of the
service area except perhaps the Forgotten Coast and southeast Big
Bend. Given the slow movement of this line, a quick couple inches
of rain should occur in spots. Gusty winds will also be a threat
with thunderstorms.

Looking upstream, a shortwave trough currently south of El Paso TX
will race east this afternoon, sparking development of a new MCS
late this evening off the Texas and Louisiana coasts. It will
continue to race east overnight near the northern Gulf Coast,
pushing across the tri- state region on Saturday morning. Assuming
this takes on a classic MCS structure and tracks more onshore than
over the Gulf waters, then fairly widespread severe wind gusts
would be possible, with isolated convective gusts in excess of 70
mph.

As is common with an exiting MCS, would not be surprised to see a
significant lull in activity develop sometime in the afternoon or
evening in the rain-stabilized air that follows.

&&

.SHORT TERM...
(Saturday through Sunday night)
Issued at 213 AM EDT Fri May 17 2024

Uncertainty remains high through the short period as a lot of
what happens in this period, especially through the day on
Saturday, will depend on how convection evolves through Friday and
overnight into Saturday morning to our west. Elevated
southwesterly flow will be firmly entrenched over the forecast
area into Saturday as the next, possibly last, shortwave in the
southwesterly flow will be approaching by daybreak. The timing of
this wave will help determine how far west favorable forcing and
instability develop through the morning and afternoon hours.
Further complicating matters will be the eastward progression of a
potential MCS (organized complex of storms) in the morning.
Should this MCS plow through quickly ahead of the upper level
shortwave, it is possible this could lower severe probs for our
afternoon severe threat. With a slower shortwave/MCS and
sufficient shear of 40 to 50 knots in place, we will likely
realize some severe potential amongst the relatively large mid-
level lapse rates and modest instability. More organized storms in
this environment will likely bring a greater wind potential. With
the steeper lapse rates, large hail is also possible, but confidence
is lower in that threat materializing. A brief tornado can`t be
ruled out either but with low-level shear fairly low and very weak
turning in the low-level hodographs, the damaging wind and hail
threat will be the main hazards folks this weekend need to be
monitoring.

Widespread showers, in addition to scattered severe storms,
continue into the evening hours but a general downtrend in severe
weather should begin to develop as the forcing moves east and
instability wanes. However, with one last shortwave passage left, isolated
severe storms remain possible overnight Saturday into early
Sunday.

The trough pushes through Sunday with cooler temperatures aloft
moving in. While the severe threat will be noticeably lower and
east compared to Saturday`s event, our GA counties along the I-75
corridor and down into the southeast Big Bend could see strong,
possibly severe, storms given the favorable temperatures aloft
and remnant instability.

&&

.LONG TERM...
(Monday through Thursday)
Issued at 213 AM EDT Fri May 17 2024

Upper level ridge settles in as the trough from the weekend moves
out. A quieter and drier pattern is forecast through much of next
week. This pattern should lead to a warm up in temperatures with
highs back in the low 90s by Tuesday and Wednesday.

&&

.AVIATION...
(18Z TAFS)
Issued at 1202 PM EDT Fri May 17 2024

The main challenge will be timing two rounds of showers and
thunderstorms over the next 24 hours, with the possibility of a
thunderstorm squall line on Saturday morning that could bring a
healthy coverage of severe thunderstorm wind gusts.

Radar currently shows an east-west band of moderate rain and
embedded thunderstorms over east-central Alabama and west-central
Georgia. This will start to move southeast this afternoon, likely
affecting the terminals through early evening.

A lull is likely overnight, then the squall line will move in from
the west on Saturday morning.

&&

.MARINE...
Issued at 1202 PM EDT Fri May 17 2024

Moderate southerly breezes will prevail across the northeast Gulf
through Saturday evening. However, a line of thunderstorms is
likely to move across the waters on Saturday morning, bringing
strong to severe wind gusts. A weak front will move across the
waters on Saturday night, followed by a turn to westerly breezes.
High pressure will pass across the northeast Gulf on Sunday night,
and then elongate along the U.S. Eastern Seaboard on Monday and
Tuesday.

&&

.FIRE WEATHER...
Issued at 213 AM EDT Fri May 17 2024

For today and Saturday, multiple clusters of thunderstorms are
likely to cross the area, with the heaviest rain and greatest
potential for severe storms coming on Saturday. Behind the front on
Sunday afternoon, the air mass will start to dry out. High afternoon
dispersion is forecast over inland districts on Sunday afternoon due
to a deep mixed layer and moderate westerly transport winds.

&&

.HYDROLOGY...
Issued at 213 AM EDT Fri May 17 2024

The Ochlockonee and upper portions of the Withlacoochee Rivers
have crested or will crest in the next 24 to 36 hours. After the
crests, gradual reductions should continue. However, more rain is
on the way this week with widespread rainfall amounts of 1 to 2
inches. These amounts on their own shouldn`t cause additional
issues but localized higher amounts could cause further rises on
already elevated rivers.

&&

.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   86  74  86  70 /  50  30  90  50
Panama City   82  73  82  70 /  80  50  80  40
Dothan        84  71  78  67 /  70  50  90  30
Albany        85  71  82  67 /  80  50  90  40
Valdosta      88  74  87  69 /  30  40  90  60
Cross City    87  73  87  70 /  40  10  50  70
Apalachicola  81  75  82  72 /  80  30  70  50

&&

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

GA...None.
AL...None.
GM...None.
&&

$$

NEAR TERM...Haner
SHORT TERM...Dobbs
LONG TERM....Haner
AVIATION...Haner
MARINE...Haner
FIRE WEATHER...DVD
HYDROLOGY...Dobbs