838
FXUS62 KJAX 241544
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
1144 AM EDT Sun Aug 24 2025

...DOWNPOURS & STRONG STORMS SOUTH OF I-10 LATE THIS AFTERNOON...
...DANGEROUS RIP CURRENT RISK FOR THE NORTHEAST FL BEACHES...
...DRIER AND SLIGHTLY COOLER AIR ARRIVES EARLY THIS WEEK...

For the latest NE FL and SE GA Daily Key Messages please visit:
https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

.UPDATE...
Issued at 1145 AM EDT Sun Aug 24 2025

Late morning surface analysis depicts developing low pressure
(1007 millibars) situated along a frontal boundary off the
Carolina coast. This slow moving boundary extends along the
Interstate 10 corridor in north FL this morning. Meanwhile, a
cold front was pushing southeastward across the eastern Great
Lakes and the Ohio/Tennessee Valleys and the Ozarks, with strong
high pressure (1028 millibars) building over the Northern Plains
states in the wake of this cold front. Aloft...a potent shortwave
trough traversing the Great Lakes region was carving out a
longwave trough over the eastern half of the nation. Deep
southwesterly flow prevails at the base of this trough across our
region above 700 millibars (around 10,500 feet) per the morning
sounding at Jacksonville, with shortwave impulses embedded within
this southwesterly flow triggering widespread convection across
the northern and eastern portions of the Gulf, with this activity
extending across the FL peninsula, mostly from the I-4 corridor
southward. Latest GOES-East derived Total Precipitable Water
imagery indicates that a drier air mass was beginning to advect
southeastward across the Ocmulgee and Alapaha rivers in interior
south GA, where PWATs were falling below 1.75 inches. Deep
tropical moisture otherwise prevails over our area, with PWAT
values around 2 inches for locations along and north of I-10,
while values were around or in excess of 2.25 inches for areas
south of I-10.

Scattered low-topped showers were developing along the frontal
boundary near I-10 in the Suwannee Valley, with activity pushing
southeastward due to lower level northwesterly flow in the wake of
departing low pressure off the southeastern seaboard. Mostly low
and mid level clouds prevail area-wide late this morning, with
temperatures at 15Z climbing to the upper 70s and lower 80s at
most locations. Dewpoints were already falling into the mid and
upper 60s for locations north and west of Waycross, while 70s
prevail elsewhere.

The drier air mass spilling into southeast GA this afternoon
should limit coverage of showers and thunderstorms later today to
isolated to widely scattered at best. Showers currently developing
along the slow moving frontal boundary near and south of the I-10
corridor should continue to gradually increase in coverage and
intensity this afternoon. Meanwhile, convective outflows pushing
northward from current activity in central FL will collide with
mesoscale boundaries and convection along the frontal boundary
late this afternoon, with storms potentially pulsing and moving
slowly over southern portions of the St. Johns River basin as well
as north central FL. Localized flooding and a few strong storms
will be possible, especially over eastern Marion, Putnam, Flagler,
and St. Johns Counties, where widespread rainfall amounts of
around 1 inch with localized totals of 2-4 inches will present a
localized flood threat, especially for normally flood prone, urban
locations such as Palatka during the late afternoon and early
evening hours. Breaks in the multi-layered cloud cover this
afternoon should allow highs to climb to the mid and upper 80s,
with a few locations possibly touching 90 degrees.

Convection may linger across north central FL and southern
portions of the Suwannee Valley this evening as southwesterly flow
aloft and shortwave energy continues to develop widespread
convection across the eastern Gulf overnight. Widely scattered
convection may push onshore from the FL Nature Coast and Big Bend
into western and central portions of Marion County and possibly
southern portions of the Suwannee Valley overnight as the frontal
boundary pushes across north central FL. Mid and high altitude
cloud cover emanating from this activity may shroud our skies
overnight, keeping lows around 70 for inland southeast GA and the
low to mid 70s elsewhere.

&&

.SHORT TERM...
(Monday through Tuesday night)
Issued at 230 AM EDT Sun Aug 24 2025

Diurnal convection will become more inhibited on Monday and and
Tuesday as drier air and more stable conditions settle in over the
forecast area following the passage of a late summer dry front,
bringing PWAT values potentially as low as 0.60 to 0.75 inches.
High temperatures for the beginning of next week will rise into
the lower 90s with overnight low temperatures dropping down into
the upper 60s over southeast Georgia and in the lower 70s for
northeast Florida and for areas along the coast.

&&

.LONG TERM...
(Wednesday through Saturday)
Issued at 230 AM EDT Sun Aug 24 2025

Initially below average chances for diurnal convection will increase
by Friday with the highest chances for showers storms expected
over north central Florida as a second dry front presses down from
out of the north and stalls over Georgia with more moist and
unstable conditions ahead of the boundary. Daily high temperatures
will experience a mild cooling trend through the end of the week
with max temps dropping below the seasonal average.

&&

.AVIATION...
(12Z TAFS)
Issued at 812 AM EDT Sun Aug 24 2025

IFR conditions at the Duval County terminals and SGJ will quickly
improve to MVFR at these terminals around or shortly after 13Z.
Otherwise, VFR conditions are expected to prevail through at least
16Z at SSI and GNV. Showers and thunderstorms are expected to
develop south of the Interstate 10 corridor early this afternoon,
with activity potentially expanding northward during the mid to
late afternoon hours. Highest confidence for impacts this
afternoon will be at the GNV and SGJ terminals, where TEMPO groups
were used through sunset for briefly gusty surface winds and IFR
visibilities during heavier downpours. PROB30 groups for briefly
gusty surface winds and MVFR conditions during heavier downpours
were maintained late this afternoon through early this evening at
the Duval County terminals. Confidence was only high enough for a
vicinity shower mention after 17Z at SSI, where VFR conditions
should otherwise prevail. VFR conditions should then prevail at
the northeast FL terminals after 02Z Monday, with MVFR to IFR
visibilities expected to develop during the overnight and predawn
hours at VQQ and GNV. Northwesterly surface winds will develop
towards 13Z at the regional terminals, with speeds increasing to
5-10 knots by 15Z. The Atlantic sea breeze boundary will shift
surface winds to northeasterly around 10 knots at SSI and CRG by
20Z.

&&

.MARINE...
Issued at 1145 AM EDT Sun Aug 24 2025

Long period swells will continue to impact our local waters,
keeping combined seas elevated through tonight. Areas near inlets
may be choppy from this swell activity today. Small Craft should
Exercise Caution if venturing offshore, where seas of 4 to 6 feet
will continue through tonight before subsiding to 3-5 feet on
Monday and Tuesday. Seas near shore will remain in the 3-4 foot
range through Monday. Meanwhile, a slow moving cold front
positioned across Interstate 10 this morning will slowly drift
southward through tonight. Showers and thunderstorms will impact
our local waters this afternoon through early evening. The frontal
boundary will then push south of our local waters on Monday
evening, stalling across the Florida peninsula by midweek,
resulting in a decreasing coverage of showers and thunderstorms
for our area on Tuesday and Wednesday. Breezy northeasterly winds
will may then develop by Wednesday and Thursday as high pressure
builds over the Ohio Valley and coastal troughing develops across
the northeast Florida waters, where chances for showers and
thunderstorms will increase later this week.

Rip Currents: Long period swells of 3-5 feet with swell periods of
13-15 seconds will continue today. Breakers of 2-4 feet at the
northeast FL beaches will keep a high risk of rip currents in
place today, while breakers of around 2 feet at the southeast GA
beaches keep a higher end moderate risk in place. Lengthy swell
periods will likely keep an elevated rip current risk in place on
Monday and Tuesday at area beaches.

&&

.FIRE WEATHER...
Issued at 1145 AM EDT Sun Aug 24 2025

Light northwesterly surface and transport winds today for
locations along and north of Interstate 10 will yield low daytime
dispersion values. West-southwesterly transport winds will become
breezy this afternoon across north central FL, where fair daytime
dispersion values are forecast. Poor values are expected elsewhere
today. West-northwesterly surface and transport winds are forecast
for locations along and north of I-10 on Monday, with breezy
southwesterly transport winds continuing across north central FL.
Elevated mixing heights on Monday will create good daytime
dispersion values at inland locations, with fair values forecast
at coastal locations. Surface and transport winds will then become
northwesterly area-wide by Tuesday morning, with northeasterly
surface winds developing at coastal locations during the
afternoon hours, where fair values are forecast. Elevated mixing
heights will again yield mostly good daytime dispersion values at
most inland locations on Tuesday afternoon.

&&

.HYDROLOGY...
Issued at 1145 AM EDT Sun Aug 24 2025

Slow moving downpours and embedded thunderstorms are expected to
develop during the mid to late afternoon hours, mainly for
locations south of the Interstate 10 corridor. The Weather
Prediction Center has included these areas within a "Marginal"
Risk (level 1 of 4) for Excessive Rainfall later today and this
evening. Widespread rainfall totals of around 1 inch, with
localized totals of 2-4 inches will be possible, with short-term,
high resolution guidance indicating that areas most at risk for
flooding downpours will be across southern portions of the St.
Johns River basin, mainly for Putnam, St. Johns, and Flagler
Counties.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  88  70  91  65 /  30  20  10   0
SSI  86  74  90  72 /  50  30  30  10
JAX  87  72  93  71 /  70  40  50  10
SGJ  88  74  91  75 /  70  60  60  20
GNV  88  72  92  72 /  70  50  60  10
OCF  87  73  90  73 /  80  40  80  10

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through late tonight for FLZ124-125-138-
     233-333.

GA...None.
AM...None.
&&

$$