896
FXUS62 KJAX 031246
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
846 AM EDT Wed Sep 3 2025

...HIGH RISK OF RIP CURRENTS AT THE NORTHEAST FL BEACHES TODAY...
...MINOR TIDAL FLOODING WITHIN THE ST. JOHNS RIVER BASIN...
...SEASONABLY HOT AND HUMID WEATHER FRIDAY THROUGH THE WEEKEND...

.UPDATE...
Issued at 840 AM EDT Wed Sep 3 2025

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

Current forecast on track with northeasterly low level flow prevailing
with most of any moisture in the lowest levels. Any potential
convective shower or weak t-storm activity expected to be only
affecting Flagler, St Johns, Putnam and possibly Marion.
Otherwise, sunny to partly sunny skies today with breezy northeast
winds at times, with gusts up to 20-30 mph near the coastal
areas. No change in the high temps today. For tonight, there is an
indication in guidance that we may see slightly better chances of
showers along the coastal areas as winds veer, so will take a
look at new 12z guidance for any changes and have an update for
the afternoon forecast.

For the marine forecast, seas are up at 6 ft at the St Augustine
buoy and will only slowly fall during the day. Earlier this morning,
ASCAT winds showed 15-20 kt over the area waters. This may keep
some higher seas going for the area waters. Thus, based on this
data and SAUF1 at 16 kt, inserted small craft exercise caution
rest of today. Winds and seas should relax tonight.

&&

.NEAR TERM...
(Today and Tonight)
Issued at 401 AM EDT Wed Sep 3 2025

The low-pressure trough south of the area and high pressure to
the north will keep the northeasterly flow through this afternoon.
This will result in scattered showers and thunderstorms,
particularly along the coast as moist marine air continues to be
brought onshore. Drier air from the north will limit precipitation
chances for inland locations of southeast Georgia. Through the
day, the local pressure gradient will begin to relax, allowing for
winds to gradually diminish, with gusty winds still along the
coast. With the persistent northeasterly flow, the Coastal Flood
Advisory will remain in place.

Daytime highs will be in the upper 80s to lower 90s across inland
locations, while cooler marine air will help to keep coastal
locations in the lower to mid 80s. Overnight lows will primarily
be in the upper 60s to lower 70s.

&&

.SHORT TERM...
(Thursday through Friday night)
Issued at 401 AM EDT Wed Sep 3 2025

Flow aloft will become zonal across the southeastern states on
Thursday as troughing becomes cutoff over the Great Lakes,
Northern Plains states and the Upper Midwest. This weather pattern
will allow a frontal boundary that is currently stalled across the
FL Straits to lift slowly northward across south FL, with weak
cyclogenesis progged along this front near the northwestern
Bahamas. An unseasonably dry air mass will persist throughout
southeast GA and northeast FL, where PWATS around 1.5 inches will
maintain dry weather. Just enough moisture may be available for
very isolated late afternoon and evening convection to develop
over north central FL, mostly near the I-75 corridor, where the
Atlantic and Gulf coast sea breezes will collide towards sunset.
Plenty of sunshine and a dry air mass will allow highs to climb
to the low and mid 90s for locations west of the I-95 corridor,
with upper 80s prevailing along the Atlantic coast, where a light
onshore breeze will prevail.

Low level flow will shift to a more southerly direction on
Thursday night, which will keep lows in the upper 60s to around 70
despite fair skies at inland locations, except lower 70s for north
central FL and mid 70s at coastal locations.

The frontal boundary over south FL will continue to lift slowly
northward on Friday as low pressure offshore of the east central
FL coast moves slowly eastward. The dry air mass will remain in
place over southeast GA, with PWATs slowly climbing back up
towards early September climatology over northeast and north
central FL, which may help to ignite isolated afternoon convection
along inland moving sea breezes, mainly for locations south of the
I-10 corridor, with widely scattered coverage possible into the
early evening hours for north central FL. The lingering dry air
mass and mostly sunny skies will again boost highs into the low to
mid 90s for locations west of I-95, with highs in the upper 80s to
around 90 for coastal locations, where an onshore breeze will
prevail. Afternoon heat index values may approach 100 for inland
locations south of I-10.

Fair skies and light winds will allow lows to fall to around 70 at
inland locations on Friday night, while a light onshore breeze
again keeps lows in the mid 70s along the Atlantic coast.

&&

.LONG TERM...
(Saturday through Tuesday)
Issued at 401 AM EDT Wed Sep 3 2025

Zonal flow aloft on Saturday will maintain an unseasonably dry air
mass across southeast GA, while PWATs climbing to near early
September climatology allow for isolated to widely scattered
afternoon and evening showers and thunderstorms to develop for
locations south of the I-10 corridor. Seasonably hot and
increasingly humid conditions are otherwise expected across our
region this weekend, with inland highs soaring to the mid 90s,
while a light onshore breeze keeps coastal highs closer to 90.
Heat index values may approach 105 degrees across northeast and
north central FL, with values near 100 for southeast GA. Lows this
weekend will remain in the 70s area-wide.

A potent shortwave trough traversing the Great Lakes region this
weekend will carve out a broad trough across the eastern half of
the nation by Sunday and Monday. This trough will drive a cold
front into the southeastern states by Sunday afternoon and
evening, but a lingering dry air mass over our area should keep
convective coverage to isolated or widely scattered at best. This
trough will capture the remnant moisture from eastern Pacific
Tropical Cyclone Lorena early next week, with a southern stream
trough carrying this moisture across the lower Mississippi Valley
on Monday and across our region by Tuesday. Meanwhile, high
pressure building over the Upper Midwest in the wake of the
aforementioned cold frontal passage late this weekend will shift
eastward across the Great Lakes region by Monday, with this
feature then expected to wedge down the southeastern seaboard by
Monday night and Tuesday. This weather pattern will result in the
frontal boundary stalling near the FL/GA border early next week.

Deeper moisture will pool along the stalling frontal boundary over
our area, and onshore winds will also strengthen early next week
as our local pressure gradient tightens. Showers and embedded
thunderstorms will increase in coverage on Monday, especially
during the afternoon hours along the I-95 and U.S.-301 corridors
as onshore winds become breezy at coastal locations. Highs will
still climb to the upper 80s and lower 90s for locations west of
the I-95 corridor, with mid to upper 80s elsewhere. Convective
coverage should then increase by Tuesday as Lorena`s remnant
moisture arrive across our area from the west and onshore flow
strengthens further, with the potential for locally heavy
downpours and minor tidal flooding along the Atlantic coast and
within the St. Johns River basin due to the combination of higher
astronomical tides and breezy onshore winds (see "Coastal
Flooding" section below for preliminary details). Increasing cloud
cover and rain chances will likely keep highs in the mid to upper
80s, and lows will remain in the 70s early next week area-wide.

&&

.AVIATION...
(12Z TAFS)
Issued at 840 AM EDT Wed Sep 3 2025

VFR clouds expected today with only a brief period of MVFR possible
for SGJ due the moisture moving onshore from northeasterly winds.
Should see at least scattered cumulus during the aftn heating but
largely VFR cumulus expected. Only showers looks like they would
stay to the southeast of SGJ at this time today. For winds,
northerly winds of about 5-8 knots now will shift to more
northeast by mid morning and increase to about 8-12 kt by late
morning.

&&

.MARINE...
Issued at 401 AM EDT Wed Sep 3 2025

Low pressure positioned east of the Gulf Stream waters adjacent to
the southeastern seaboard will weaken as it moves further offshore
today and tonight. Meanwhile, high pressure along the U.S. eastern
seaboard today will weaken as it pushes offshore tonight. Breezy
northeasterly winds will continue today as seas continue to
gradually subside, with scattered showers possible for the waters
south of St. Augustine. Meanwhile, a frontal boundary currently
stalled near the Florida Keys will lift slowly northward through the
Florida peninsula on Thursday and Friday, with another weak low
pressure center developing along this front east of Cape Canaveral.
This feature will likely maintain generally light onshore winds
across our local waters through the weekend. A frontal boundary will
then approach our region from the northwest on Sunday, with this
front then stalling across our local waters early next week,
bringing increasing chances for showers and thunderstorms.

Rip Currents: Breezy northeasterly winds will maintain breaker
heights of 3-4 feet at the northeast FL beaches, with 2-3 foot
breakers expected at the southeast GA beaches. We will extend the
high rip current risk today at the northeast FL beaches, with a
higher end moderate risk for the southeast GA beaches. Breakers
will diminish to 2-3 feet at the northeast FL beaches on Thursday
and to around 2 feet at the southeast GA beaches, with a moderate
risk predicted for all area beaches expected from Thursday
through the upcoming weekend.

&&

.FIRE WEATHER...
Issued at 401 AM EDT Wed Sep 3 2025

An unseasonably dry air mass will remain in place for locations
along and north of the Interstate 10 corridor through Friday.
Breezy northeasterly surface and transport winds will continue
today along the Interstate 95 corridor, with elevated mixing
heights allowing for fair to good daytime dispersion values
despite light speeds well inland. Surface and transport winds will
become easterly along the I-95 corridor and southeasterly further
inland on Thursday and Friday, with breezy surface winds
developing at coastal locations by early afternoon both days.
Elevated mixing heights will again yield fair to good daytime
dispersion values.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  87  64  91  68 /   0   0   0   0
SSI  84  73  86  74 /   0   0   0   0
JAX  88  70  91  72 /  10  10  10   0
SGJ  87  74  88  75 /  20  10  20  10
GNV  91  69  93  70 /  10  10  20  10
OCF  90  71  91  73 /  10  10  30  10

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 6 AM EDT Friday for FLZ038-132-137-
     138-233-333-633.

     High Rip Current Risk through late tonight for FLZ124-125-138-
     233-333.

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

&&

$$