144
FXUS62 KTAE 091715
AFDTAE

Area Forecast Discussion
National Weather Service Tallahassee FL
115 PM EDT Thu May 9 2024

...New AVIATION...

.UPDATE...
Issued at 1037 AM EDT Thu May 9 2024

Tweaked the PoP forecast starting this morning and continuing
through the early evening. Outside of that no major changes were
made to the forecast.

For what`s going on right now, the morning stratus has broken
apart with cumulus clouds taking over the region. To our north,
around and south of I-85 scattered to widespread convection is on
going and traveling eastward. To the north of that a line of
storms is diving to the southeast. Expect growth in these areas to
continue with a more linear form pushing south into our region.
Though some cells could develop ahead of that.

SPC Mesoanalysis page is starting to line up with the near term
forecast below. All modes of severe weather remain possible, with
damaging to destructive winds continuing to have the highest
threat. Large hail, especially with the more unidirectional flow
aloft, and a few tornadoes remain possible. Current analysis
shows 2500-3000 J/kg SBCAPE and MUCAPE, with ML CAPE more diverse
1000 J/kg East, the 1500 J/kg contour along the Chattahoochee, and
around 2000 J/kg along the western FL Panhandle into SE AL. DCAPE
looks particularly juicy too this early, with 600-900 J/kg along
and west of the Chatahoochee and Apalachicola Rivers. Shear
remains bountiful as well, and the 12Z sounding shows some
southwesterly winds in the lower levels with strong westerlies in
the mid to upper levels, giving more unidirectional shear.

&&

.NEAR TERM...
(Today and tonight)
Issued at 431 AM EDT Thu May 9 2024

An active next 36 hours is upon us with 2 rounds of severe
thunderstorms, the first round arriving early this afternoon across
our northern counties and working south into the evening hours.
Round two will arrive in the overnight hours from west to east and
this second round appears to be the more significant of the two
rounds. All modes of severe weather will be possible with damaging
to destructive winds as the highest threat. SPC for today has
expanded the enhanced risk (level 3 of 5) further south to the
Florida state line with the slight risk (level 2 of 5) also expanded
further south to include all our coastal sections. SPC continues the
marginal risk for Friday (level 1 of 5) across our entire area with
the exception from Albany to Bainbridge to Tallahassee and points
eastward have been upgraded to a slight risk.

Mid level flow will become more zonal today as a mid level high
retrogrades into Mexico and an upper low retrogrades towards the
Great Basin. A shortwave trough is supporting widespread development
of storms currently in the Mid-South and Tennessee Valley which will
gradually move southeast today. The atmosphere will remain unstable
this afternoon with SBCAPE 2000-3000 J/kg, MLCAPE 1000-2000 J/kg,
and DCAPE of 1000-1500 J/kg. Coupled that with bulk shear around 40
knots and mid level lapse rates of 7-8 C/km and severe thunderstorms
will be likely with both rounds this afternoon and overnight. Latest
CAMs have the first round making it south into the Big Bend into the
early evening hours which is a slight change from a few runs ago and
have increased pop chances here through 00Z.

Round 1 Timing will begin around 12pm ET in our northern and
northwestern sections in AL and GA, moving south through the day,
arriving into the Florida Big later this afternoon into early
evening.

&&

.SHORT TERM...
(Friday through Saturday night)
Issued at 431 AM EDT Thu May 9 2024

Throughout Friday the ridge slides eastward as a trough looks to
move across eastern CONUS. A fast moving shortwave coming off the
Rockies zooms eastward merging with another shortwave rounding the
base of the developing trough. As these two features merge, over the
southeast, early Friday morning into Friday afternoon, our risk for
severe weather increases. This correlates with why the SPC has our
region, north of I-10, under a Enhanced Risk (level 3 of 5) for
severe weather through 8am ET Friday. Areas east of a line from
Albany, GA to Tallahassee, FL are under a Slight Risk (level 2 of 5)
through the rest of Friday. With low-level winds possibly around 30-
45 kts, PWATs around 2 inches and a defined shortwave providing
forcing for ascent via PVA, the ingredients for severe would be
present. All hazard types are possible, with hi-res guidance
indicating a preference towards QLCS solutions, strong damaging
winds would be our primary hazard of concern. Depending on how far
south the first round of severe weather gets today (Thursday) will
determine where our second round ends up as it seeks out higher
instability. How late into the day on Friday the front decides to
move across the region will also determine if we see diurnal
instability aid in forcing for ascent for additional showers and
storms throughout Friday afternoon. With higher PWATs comes an
increased risk of torrential downpours leading to localized flash
flooding issues. Which is why we`re under a slight and marginal
risk for excessive rainfall from WPC.

The front is expected to clear the region by Friday night. Clear and
dry conditions are in store through the rest of the weekend.

Expect daytime highs generally in the low to mid 80s with overnight
lows generally in the low 70s tonight before frontal passage.
Overnight lows will then be in the low 60s Saturday morning after
frontal passage.

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 431 AM EDT Thu May 9 2024

Being post-frontal will lead to relatively cooler temps and a
decrease in moisture as northerly flow prevails through Monday
morning. Although surface winds will be southerly during the
afternoon hours due to the sea breeze, high pressure will lead to
large-scale subsidence. Limiting development to fair weather Cu or
developing towers that fizzle away. On Monday another shortwave
looks to move across the northern Gulf states with our region
possibly being impacted on Tuesday as winds turn to being
southeasterly. With this shortwave possibly moving overhead, a
stationary boundary to our south, left behind from the previous
system, and a low-level wind field again around 30-45 kts, the
potential for severe is once again present. We`ll have to see how
this progresses over the next few days to have better confidence, be
sure to come back for updates.

Expect relatively cooler temps to what we`ve been experiencing as of
late. Daytime highs will generally be in the low to mid 80s with
overnight lows generally in the upper 50s to mid 60s until Tuesday
morning. Beyond Tuesday morning, overnight lows look to rebound into
the mid and upper 60s.

&&

.AVIATION...
(18Z TAFS)
Issued at 113 PM EDT Thu May 9 2024

A mix of VFR and MVFR conditions are expected to continue for the
afternoon hours for all TAF sites. Showers and thunderstorms will
increase in coverage this afternoon through the rest of the TAF
period. Some storms may be severe with destructive wind gusts and
large hail, and a few tornadoes will be possible. The timing of
storms is expected in two rounds, with the first starting this
afternoon at the beginning of this TAF period, and the second
round arriving late overnight into the morning hours on Friday.
During storms, expect poor flight conditions. Outside of storms,
we do expect gusty winds for the afternoon. Winds may gust up to
25-30kts with southwesterly winds sustained around 15-20kts.

Storms are expected to clear out of the region by the end of this
term but, there may be some lingering thunderstorms in the late
morning into early afternoon Friday. Confidence in this possible
third round is low at this time. This will be determined by how
today`s storms behave.

&&

.MARINE...
Issued at 1037 AM EDT Thu May 9 2024

An Atlantic ridge axis across the southern Florida Peninsula will
retreat southward today. A cold front will slowly approach from
the north on Friday, preceded by strong to severe thunderstorms
over the waters. Cautionary conditions could be possible. The
front will limp across the waters on Friday night. It will be
followed by moderate to occasionally fresh northerly breezes on
Saturday morning. Surface high pressure over the southern Plains
on Saturday will move across the Southeast States on Sunday,
causing winds to clock around. High pressure will move east into
the Atlantic on Monday, brining a return to south- southeasterly
flow.

&&

.FIRE WEATHER...
Issued at 431 AM EDT Thu May 9 2024

Several rounds of wetting rains and possible severe thunderstorms
are on tap through Friday afternoon. The first round will arrive
into our southeast Alabama and southwest Georgia area early this
afternoon then move south into our Florida counties by mid to late
afternoon. There appears to be a lull this evening ahead of the
second round of storms in the overnight into Friday morning hours
moving from west to east. All modes of severe weather will be
possible with the storms with damaging to destructive winds as the
highest threat. Outside of rain and storms, high dispersions are
possible today along the I-75 corridor westward towards the
Apalachicola river. Conditions improve behind these rounds of storms
heading into this weekend.

&&

.HYDROLOGY...
Issued at 431 AM EDT Thu May 9 2024

A slight risk of excessive rainfall exists for the northern half of
our area today, with a marginal risk for most of the area on Friday
as a frontal system looks to push through the region. The primary
risk here being torrential downpours or training within any
thunderstorm(s) leading to a localized flash flooding risk.
Otherwise, area rivers are expected to remain below flood stage. In
the extended period the WPC is forecasting 3-5 inches by midweek
next week. This could introduce some riverine concerns, however,
it`s too far out to say with any degree of confidence.

&&

.SPOTTER INFORMATION STATEMENT...

Spotter activation is requested. Spotters should safely report
significant weather conditions and/or damage by calling the
office or tweeting us @NWSTallahassee.

&&

.PRELIMINARY POINT TEMPS/POPS...
Tallahassee   73  84  63  83 /  30  90  10   0
Panama City   73  83  64  83 /  20  60   0   0
Dothan        71  85  59  80 /  50  80   0   0
Albany        70  85  59  80 /  50  70   0   0
Valdosta      71  83  62  81 /  40  90  10   0
Cross City    72  85  64  85 /  20  80  30   0
Apalachicola  75  82  66  81 /  20  50  10   0

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Saturday morning for FLZ108-112-
     114-115.

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

$$

NEAR TERM...Scholl
SHORT TERM...Oliver
LONG TERM....Oliver
AVIATION...Montgomery
MARINE...Oliver
FIRE WEATHER...Scholl
HYDROLOGY...Oliver