473
FXUS62 KTAE 241019
AFDTAE

Area Forecast Discussion
National Weather Service Tallahassee FL
619 AM EDT Tue Sep 24 2024

...New AVIATION...

.NEAR TERM...
(Today and tonight)
Issued at 259 AM EDT Tue Sep 24 2024

One more day of dry and warm conditions are on tap today with highs
in the low to mid 90s. Ridging aloft begins to get shoved off to the
east by a large trough swinging south across the Plains, allowing
for rain chances to begin to increase across the Gulf and near the
coast overnight tonight. With rain chances increasing even Wednesday
ahead of the hurricane, please take advantage of the great weather
today to get your preparations underway or completed.

&&

.SHORT TERM...
(Wednesday through Friday)
Issued at 259 AM EDT Tue Sep 24 2024

Attention turns to Potential Tropical Cyclone #9 (PTC9) beginning
Wednesday, which according to latest NHC forecasts is likely to be a
hurricane as it enters the southern Gulf of Mexico between Cuba and
Mexico. Confidence is increasing for significant impacts across the
region including major hurricane force winds, life threatening storm
surge, flash flooding from heavy rainfall, and a few tornadoes.

For Wednesday across the forecast area, the region will be
between increasing southeasterly flow on gradient between surface
high pressure in the Atlantic and the tropical cyclone well to our
south, and a frontal boundary associated with a large upper level
trough across the south-central US. Compared to prior forecasts,
Wednesday is now appearing wetter, especially across our Panhandle
counties, while scattered showers and storms associated with the
very outer periphery of PTC9 likely won`t arrive until late
Wednesday into Thursday morning.

By Thursday morning, conditions could begin to deteriorate as the
outer portions of PTC9 arrive, but it`s at this point where
uncertainty in the forecast begins to vary in timing, intensity, and
track. Latest 00z GFS ensembles have trended eastward some this
morning and they continue to be some of the faster guidance in terms
of landfall/impacts timing. Similar timing was noted with the
Canadian ensembles. The 18z ensembles for the Euro were about 6 to
12 hours slower on average With that said, folks need to have
preparations wrapped up by Wednesday night because tropical storm
force conditions could arrive to our coastal communities as early as
Thursday morning.

A key point to highlight in all of the ensemble guidance is that a
wide possibility of outcomes with respect to timing, intensity, and
track is still on the table. This is important because as noted by
NHC forecast wind radii, PTC9 is likely to be a very large storm.
This means impacts from surge, rainfall, and wind will extend well
away from the center. All locations along the northern Gulf and
along the eastern portions of the Florida Big Bend and west coast of
Florida are at risk currently for a major hurricane bringing
significant wind, storm surge inundation, and rainfall.
Additionally, PTC9 is likely to have a faster than usual storm
motion as it accelerates north around landfall and moves inland.
When combined with the storm`s large size and fast forward motion,
significant winds and gusts could extend further inland than folks
are typically accustomed to seeing during tropical systems.

While we understand many individual`s first thoughts when evaluating
their risk to PTC9 is to compare it to prior storms, we caution
against doing so. Every tropical system brings a unique set of
threats and hazards, and each system brings uncertainty that can
leave you unprepared if you`re not ready for a *reasonable* worst
case scenario. Don`t underestimate the danger you could experience
with PTC9 just because you avoided impacts from previous storms.
With watches likely today, if you are under a
tropical/hurricane/surge watch or warning, be sure to check the
forecast at weather.gov (type your zip code to see watches/warnings
at your location) and read the tropical watch/warning text. These
watches/warnings will list out conditions that you should be
prepared for. These watches/warnings also list out reasonable worst
case scenarios you should be ready for at your location.

&&

.LONG TERM...
(Friday Night through Monday)
Issued at 259 AM EDT Tue Sep 24 2024

PTC9 quickly moves out of the forecast area on Friday after
daybreak with the large upper level trough likely bringing in a
period of dry conditions for the weekend. However, a trailing
cold front associated with this trough could keep allow rain
chances to return to the forecast later in the weekend or early
next week. High temperatures will generally be in the upper 80s.

&&

.AVIATION...
(12Z TAFS)
Issued at 617 AM EDT Tue Sep 24 2024

VFR conditions are expected through the period. Showers will be
possible near the Panhandle coast beginning early Wednesday
morning.

&&

.MARINE...
Issued at 259 AM EDT Tue Sep 24 2024

At 11 pm EDT, the center of Potential Tropical Cyclone 9 was over
the northwest Caribbean. It will rapidly intensify while moving
northward through the eastern Gulf on Wednesday and Wednesday
night, making landfall likely as a major hurricane on the
northeast Gulf coast on Thursday. Winds and seas will start to
decrease on Friday as the tropical cyclone moves further inland
and weakens. Broad low pressure over the Lower Mississippi Valley
on Saturday will support gentle to moderate southwest breezes.

&&

.FIRE WEATHER...
Issued at 259 AM EDT Tue Sep 24 2024

Dry and warm conditions are forecast to continue today before rain
chances increase Wednesday and Thursday as Potential Tropical
Cyclone #9 approaches the area as a strong hurricane. Heavy rain and
high winds will be expected with this system. Otherwise, there are
no fire weather concerns.

&&

.HYDROLOGY...
Issued at 259 AM EDT Tue Sep 24 2024

Primary focus over the next 60-84 hours will be the approach and
impact from potential tropical cyclone nine (PTC9). The tropical
system is expected to be a quick mover, but the combination of
rainfall ahead of the storm and then along the track of the storm
will likely result in 3-6 inches of rain with isolated heavier
amounts up to 10 inches. Because the vast majority of the rain
will fall in a very short window of time, flash flooding will be
the biggest concern, some of which could be considerable near the
core of the storm. For that reason the excessive rainfall outlook
for Thursday, as the system affects the region, has been increased
to a moderate risk, or level 3 of 4, which is both indicative of
the threat as well as the confidence at this time range.

Some models are suggesting widespread heavy rainfall covering most
or all of our river basins, moving from south to north, and this
could lead to at least minor riverine flooding at many forecast
points. In areas that exceed 6-8 inches of rain, moderate riverine
flooding would be possible. As a reminder, river forecasts only
include the next 48 hours of rainfall, so it will be until
Wednesday afternoon until all of the rainfall associated with this
system is included in our riverine forecasts. A flood watch has
been issued to cover the threat of rainfall from PTC9

We are also looking at a potentially significant and major coastal
flood threat from storm surge given the forecast with this system
in Apalachee Bay. Apalachee Bay is especially sensitive to surge
and small variations in track, intensity, and forward speed can
cause major adjustments to the surge impacts. Nevertheless, at
this point, confidence is increasing of a significant and major
coastal flood impact in Apalachee Bay in association with this
system. As we get closer to landfall, we`ll have more detail on
specific surge values. Pay close attention to the advice of
emergency management about any evacuation orders that are issued.
Remember, storm surge is especially dangerous and destructive. If
ordered to evacuate, heed the advice of emergency officials. Doing
so can save your life!

&&

.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   91  73  87  72 /   0  10  50  90
Panama City   90  74  85  72 /  20  50  80  90
Dothan        91  72  85  71 /   0  20  70  90
Albany        92  73  88  71 /   0  10  40  80
Valdosta      92  72  89  72 /   0   0  30  70
Cross City    93  73  90  74 /   0   0  60  80
Apalachicola  86  77  84  74 /  10  60  70 100

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...Flood Watch from Wednesday evening through Friday morning for
     FLZ007>019-026>029-034-108-112-114-115-118-127-128-134.

     Tropical Storm Watch for FLZ012>014-112-114.

     Hurricane Watch for FLZ015>019-026>029-034-115-118-127-128-134.

     High Rip Current Risk through late Friday night for FLZ115.

     Storm Surge Watch for FLZ115-118-127-128-134.

GA...Flood Watch from Wednesday evening through Friday morning for
     GAZ120>131-142>148-155>161.

AL...Flood Watch from Wednesday evening through Friday morning for
     ALZ065>069.

GM...Tropical Storm Watch for GMZ750-770.

     Hurricane Watch for GMZ730-752-755-765-772-775.

&&

$$

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