832
FXUS62 KJAX 300012
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
812 PM EDT Fri Aug 29 2025

...New UPDATE, AVIATION...

.UPDATE...
Issued at 744 PM EDT Fri Aug 29 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

Waves of showers and isolated storms will continue to move
eastward across the area tonight as upper level short wave energy
passes overhead with a surface front meandering across the local
area. This evening, the front was just south of the NE FL I-10
corridor, with a few isolated storms across the `unstable` sector
south of the front and offshore over the adjacent coastal waters,
while more stratiform areas of rain impacted southeast GA where
cooler temperatures and a more stable airmass prevailed. Through
the night, expect a resurrection of toward the Atlantic coast,
extending inland especially across SE GA toward daybreak Saturday
as the next short wave trough approaches and the surface front
across NE FL pivots northward, with increasing isentropic lift
north of the boundary generating more numerous showers and
isolated storms. Locally heavy rainfall will be more likely
tonight after midnight toward coastal areas, with a few rotating
cells possible over the coastal waters over the coastal waters
near and south of the front toward sunrise.

Mostly cloudy skies prevail with mild lows in the low/mid 70s to
near upper 60s toward the Altamaha River Sound.

&&

.NEAR TERM...through Tonight...

A stalled frontal zone stretched along the I-10 corridor will be
the delineating line, separating the potential for strong
thunderstorms and stratiform rain. The frontal feature along with
passing shortwave energy will be the primary drivers for
convection this afternoon and evening.

The stable side, north of the boundary, will continue to see
waves of rain and perhaps an elevated thunderstorms through the
rest of the day; the primary concern will be localized heavy rain
in those areas, which is mainly SE GA.

Along and more so south of the boundary, a destabilizing airmass
will be supported by broader lift offered up by a shortwave
impulse diving across the region late this afternoon and evening.
Despite poor lapse rates, instability is still expected to reach
1500-2000 J/kg of CAPE. Coupling that buoyancy with the unusually
long and slightly curved hodographs, there will be a marginal
severe potential where instability is maximized late this
afternoon across north-central FL (roughly south of a line from
Gainesville to St Augustine). It is in those areas, especially
near the coast, where mildly organized convection may develop and
primary concerns will be strong wind gusts 40-60 mph and small
hail; however, the potential for quick- spin ups is marginal but
cannot be ruled out.

Deep moisture has already shown to be a catalyst in heavy
downpours as radar-estimated rain rates from the AM convection
reached upwards of 5" per hour. So, given the history it`s
probable that efficient rainfall will continue a localized flood
threat particularly in urban and flood-prone areas.

Tonight, there will be some lingering activity as the shortwave
energy passes but the strongest activity should subside after
sunset. Coastal convergence over nearshore waters and overrunning
may aim a few heavy showers into the coast.

Unseasonably cool conditions are expected (and welcome) across SE GA
where highs today may only touch the low/mid 80s due to the
extensive cloud cover trailing over the area. It`ll be warmer south
of the front but highs should still push toward the upper 80s.
Likewise, lows will be cooler across SE GA in the upper 60s to
around 70s and in the low 70s in NE FL.

&&

.SHORT TERM...(Saturday through Sunday Night)

Generally the same old song and dance pattern continues for the
first two thirds of the holiday weekend, as little change with
respect to the nearly stalled frontal boundary is expected.
Saturday is expected to be particularly unsettled as a shortwave
impulse digs southeastward around the base of an upper trough,
helping to support better lift as well as some slightly cooler
temperatures aloft. Instability will likely be the largest
uncertainty given plenty of cloud cover, some showers and isolated
t`storms likely affecting some areas in the morning hours, in
addition to temperatures only topping out in the low to mid 80s
for most. However, the developing sea breeze combined with the
presence of the front and weak shortwave should be enough to fire
convection during the afternoon and evening hours, with the main
focus area being from about I-10 southward in northeast FL. Heavy
rainfall will be the main hazard, though some isolated stronger
cells that take advantage of the highest instability could produce
downbursts of 40+ mph. A few showers continue overnight near the
coast, but mostly clear to partly cloudy otherwise with lows in
the upper 60s to mid 70s expected.

Flow aloft shifts towards the northwest on Sunday and Sunday
Night as high pressure ridging to the north of the area tries to
build slightly further south into northeast FL. This will both
increase the northeasterly onshore flow and push the frontal
boundary further southward, and temper rain chances the further
north and west you go with some drier air aloft. However, closer
to the boundary and higher moisture in northeast FL will be where
you will find the highest chances for showers and t`storms with
the onshore breeze, especially for areas where diurnal instability
peaks higher with less chances of rain during the morning hours.
High temps will be slightly warmer Sunday, though still generally
in the mid 80s. Isolated to widely scattered showers may once
again affect areas near the coast Sunday Night with lows in the
upper 60s to mid 70s once again.

&&

.LONG TERM...(Monday through next Friday)

Fall-like upper troughing will continue to be the main driving
force of our weather through much of the long term period,
featuring only some "wobbling" north and south of a frontal
boundary and several shortwave impulses moving around the base of
the trough across or just north of the region. This pattern/regime
will continue an unsettled pattern for most of the area but
especially for northeast FL, featuring daily scattered to numerous
showers and t`storms and a breezy northeasterly onshore flow with
ridging located to our north. Towards the end of the long term
period, guidance suggests that the base of the upper trough may
dig all the way into north an central FL, which could once again
bring a surge of drier air across the region. Temperatures start
below normal for the look term before trending towards near normal
by Wednesday/Thursday.

&&

.AVIATION...
(00Z TAFS)
Issued at 744 PM EDT Fri Aug 29 2025

Showers and multi-layered clouds will continue to pass over the
terminals tonight with increasing rain chances at coastal
terminals after 04z. The lower cloud bases (MVFR to IFR) will
focus north of the front zone at SSI, JAX, CRG and VQQ through 12z
with more intermittent MVFR in passing showers at GNV and SGJ, and
potentially a lone storm. After 06z, coastal shower activity
increases through 12z. With rain chances > 60% after 12z Saturday,
added SHRA and VCTS to most terminals with rain shifting inland
toward GNV into the afternoon. NNE winds at the coast will become
more ESE through the night as the frontal zones across NE FL
lifts northward. Increases chances in all model guidance of MVFR
to IFR ceilings after 18z Saturday as broad low forms along the
front across the local area.

&&

.MARINE...

A stationary front will linger through the weekend as high
pressure strengthens from the north, sending a surge of
northeasterly winds into the waters by Sunday. Strengthening high
pressure will continue breezy northeasterly winds through Monday
as wedges south along the Mid Atlantic and southeastern coast.
Winds will peak near Small Craft Advisory levels Monday and
gradually weaken through Wednesday. Winds are expected to shift
offshore as a trough of low pressure lifts out of the Gulf. With
little movement in the front, waves of showers and embedded
thunderstorms are expected through Monday. There will be the
potential for isolated strong storms capable of excessive
lightning, strong winds, and isolated waterspouts with the
stronger activity.

Rip Currents: Moderate Risk through Saturday; a surge of
northeast winds and building surf will increase Rip Current risk
to high levels on Sunday for SE GA beaches and increase at NE FL
beaches by Labor Day.

&&

.HYDROLOGY...
Issued at 421 AM EDT Fri Aug 29 2025

Locally heavy downpours will be possible this afternoon and
evening, especially for locations along and south of the
Interstate 10 corridor. The Weather Prediction Center has
outlooked most of our area within a "Marginal" Risk (Level 1 of 4)
for Excessive Rainfall later today. Downpours will likely become
more widespread on Saturday afternoon and evening, with waves of
downpours likely continuing through Sunday area-wide. Marginal
Risks for Excessive Rainfall continue this weekend, with the
threat for localized flooding then shifting to northeast and north
central FL during the early to middle portions of next week. As
ground conditions continue to become more saturated, Flood Watches
could be issued during the weekend and early next week, especially
for northeast and north central FL, where total rainfall amounts
of 2-5 inches are expected, with locally higher amounts possible.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  69  81  67  84 /  60  80  20  40
SSI  73  83  73  84 /  70  80  50  60
JAX  72  85  71  86 /  70  90  40  80
SGJ  73  85  72  85 /  60  90  50  80
GNV  71  87  70  87 /  30  80  30  80
OCF  73  87  71  87 /  20  80  30  80

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&

$$