296
FXUS62 KJAX 131829
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
229 PM EDT Wed Aug 13 2025

...New NEAR TERM, SHORT TERM, LONG TERM, AVIATION, MARINE...

.NEAR TERM...
(Through Tonight)
Issued at 220 PM EDT Wed Aug 13 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

Sfc ridge is noted over south central FL with weak trough over
AL/western FL panhandle. Sfc winds show weak flow over northeast
FL, but moderated by east coast sea breeze moving inland. Some
slight south flow noted inland northeast FL. Further northward
into southeast GA, flow is southwesterly but onshore flow with the
east coast sea breeze for coastal southeast GA. MLCAPE values at
18z are in the 2-3K range with one area of peak values near 3400
from Nahunta to Jesup GA.

Isolated to scattered showers and storms have formed with PWAT analysis
showing most areas of 2 inches.  Rich low level moisture is in
place with mean RH of 75% or more. Expect peak heating to produce
scattered to numerous showers and storms over the next several
hours, peaking about 4 to 7 pm. Pulse, brief strong/local severe
storm possible through about 7 pm. Activity will fade after 10 pm,
but a weak sfc to mid level trough across AL/GA, rounding the mid
level ridge, will bring some lift and stronger southwest flow
late tonight that could produce isolated, weak convection over the
far western zones in the 2 AM to 7 AM time frame.

Outside of convection, temps will be in the mid 90s rest of today,
slightly lower toward the east coast with the sea breeze moving
inland slowly. Heat indices at 2 pm were in the 103 to 109 range
for most areas and so with additional heating we should see the
more sites with values push toward 108 in and around the heat
advisory area. Lows will be muggy tonight again in the mid to
upper 70s, and around 80 near the coast due to slightly stronger
west- southwest flow at 5-10 mph.

&&

.SHORT TERM...
(Thursday through Friday night)
Issued at 220 PM EDT Wed Aug 13 2025

Overall synoptic setup overall changes little on Thursday, as stacked
high pressure will remain almost directly overhead/just east of
the Florida Peninsula, inducing a southwesterly flow near the
surface. The pressure gradient will be just a bit stronger
Thursday, which will keep the sea breeze closer to the coast. The
result will be isolated to widely scattered convection beginning
near the immediate coast and western areas with the Gulf sea
breeze during the late morning and early afternoon, increasing in
coverage somewhat during the afternoon near the HWY 301 to I-95
corridor area as the sea breezes meet. Subsidence from high
pressure will result in POPs generally in the 30 to 50% range,
with the higher end chances falling mostly near the same HWY 301
to I-95 area mentioned above and from about Waycross to I-95 in
southeast GA. Usual instability and high CAPE will bring a usual
isolated chance for stronger storms in addition to locally heavy
rainfall, though temps aloft look to be slightly warmer than
normal along with the subsidence aloft, tapering the strong storm
expectation. Hot temps continue Thursday with the southwest flow,
with highs in the mid 90s and heat indices flirting with Heat
Advisory criteria once again. A final decision on potential
advisories will be made with the next forecast package. Low temps
also remain a bit milder than usual, featuring lows in the mid to
upper 70s to near 80 in some spots closer to the coast & St. Johns
River.

High pressure weakens and shifts a bit eastward on Friday, which
will weaken the low level flow as well as shifting the wind
direction more towards the west to west/northwest. Precip chances
will remain generally in the 30 to 50% range, with the higher end
of this range likely impacting areas further inland, especially
over north/central FL. The work week ends with continuing above
normal temps in the mid 90s for most and low 90s near the
immediate coast, as well as heat indices near advisory levels once
again. Friday Night will also continue the streak of milder than
usual nights as mid to upper 70s to near 80 is once again
forecast.

&&

.LONG TERM...
(Saturday through next Wednesday)
Issued at 220 PM EDT Wed Aug 13 2025

High pressure overhead remains weak for the weekend, which will also
feature what`s left of a weakening frontal boundary/trough
dropping towards the area and the pattern remaining mostly
stagnant into early next week. Coverage of showers and t`storms
are expected to increase, with POPs in the 50 to 80% range
influenced by the daily diurnal sea breeze. The boundary and
weaker ridging will also result in temperatures starting to trend
closer to climo overall.

The National Hurricane Center is continuing to issue advisories on
Tropical Storm Erin as it moves towards the Bahamas this weekend.
Though confidence is generally increasing that the system will
begin to curve away from the Florida Peninsula as it approaches
the Bahamas early next week, it is still too early to determine
what, if any, impacts for northeast Florida and southeast Georgia
given the long range nature. Continue to monitor the official
forecast from the National Hurricane Center and maintain tropical
readiness as we enter the peak of the Atlantic hurricane season.

&&

.AVIATION...
(18Z TAFS)
Issued at 220 PM EDT Wed Aug 13 2025

VFR cigs and occasional showers and storms expected to affect
most of the TAF sites with potential for MVFR cig/vis and short
period of IFR vsby. Convection threat should last through about
00z and fading through 03z. Prevailing VFR cigs overnight and
small potential for vsby at VQQ after 06z-12z. On Thursday, a
chance of showers near GNV and possibly SGJ by 14z-18z, but most
convection will likely occur after the TAF period. Generally lower
precip coverage on Thursday aftn compared to today.

&&

.MARINE...
Issued at 220 PM EDT Wed Aug 13 2025

High pressure ridge centered across the Florida peninsula will drift
southward through Friday as a trough develops over the southeastern
states. Prevailing southwest to south winds are forecast as this
trough settles over our local waters on Friday, with prevailing
onshore winds then developing by late Saturday and Saturday night
as the trough potentially organizes into a weak low pressure
center along the southeastern seaboard. Scattered afternoon
showers and thunderstorms are expected over our nearshore local
waters through Friday, with an increase in coverage possible
during the upcoming weekend. Looking ahead next week, early
indications from guidance is that easterly swells from Erin may
reach our coastal waters Monday night to Tuesday with periods of
13-16 seconds.

Rip current: General moderate risk of rip currents through
Thursday with max surf up to 2-3 ft.

&&

.HYDROLOGY...
Issued at 220 PM EDT Wed Aug 13 2025

Minor flooding possible along the Altamaha River near Baxley this
weekend as rainfall from this past weekend works it`s way through
the basin.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  75  92  75  95 /  40  30  20  40
SSI  78  93  79  93 /  30  40  30  30
JAX  76  97  77  97 /  40  50  20  50
SGJ  77  95  77  94 /  30  40  20  40
GNV  75  95  76  97 /  30  50  10  50
OCF  75  94  76  95 /  30  50  10  50

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory until 7 PM EDT this evening for FLZ023-024-030-031-
     038-124-125-132-136>138-140-225-232-233-236-237-240-325-333-
     340-425-433-533-633.

GA...Heat Advisory until 7 PM EDT this evening for GAZ136-151>154-165-
     166-250-264-350-364.

AM...None.

&&

$$