453
FXUS62 KJAX 200522
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
122 AM EDT Wed Aug 20 2025

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

...LOCAL PEAK HURRICANE ERIN IMPACTS TODAY AND THIS EVENING...

.NEAR TERM...
Issued at 120 AM EDT Wed Aug 20 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

Warming trend continues with breezy NNE winds at the coast and
passing coastal showers as Hurricane Erin tracks north, offshore
of the FL coast today and tonight. Subsidence on Erin`s west side
will limit rain chances for many inland areas today, with the
higher rain chances locally today across coastal northeast Florida
extending inland toward the St. Johns River basin. A few
diurnally driven showers and isolated storms are expected inland
this afternoon and early evening. Rain chances decreased this
evening as low level winds back WNW as Erin tracks farther NE of
the southeast region. The main local impacts from Erin will
continue to focus across the local marine waters and for coastal
communities, with details on hazards and impacts detailed below.

Temperatures will continue to warm with above normal highs today
in the low to mid 90s inland to near 90 coast with peak heat index
values near 100 degF as "drier" air mixes down today with dew
points falling into the lower 70s. Tonight, lows will range in the
70s inland, even at the coast, due to drier WNW winds.

&&

.SHORT TERM...
(Thursday through Friday night)
Issued at 120 AM EDT Wed Aug 20 2025

As Erin moves further away to the northeast Thursday, high pressure
will begin to ridge down the east coast of the US. Drier air will
remain in place over SE GA Thursday, with ridge helping to provide
subsidence. Convection Thursday will be diurnally driven. Isolated
to scattered precipitation for SE GA, and scattered to numerous for
NE FL. Highs will be above normal. Convection which does develop
during the day time, will dissipate in the evening, with a dry
overnight. Lows Thursday night in the middle 70s.

A trough will develop across the area on Friday, with moisture
increasing. The trough will provide a source for convergence. The
combination of diurnal heating, convergence along trough, and
diurnal heating in the amply moist airmass, will lead to above
average chances for showers and thunderstorms. Highs will again
trend above normal for Friday. While convection will diminish
during the evening with loss of diurnal heating, the presence of
the trough in the moist airmass may lead to showers lingering into
the overnight hours. Lows Friday night in the lower to mid 70s
will be common.

&&

.LONG TERM...
(Saturday through Tuesday)
Issued at 120 AM EDT Wed Aug 20 2025

Troughing will prevail across the area for much of this period. With
this trough in place providing convergence, daily rounds of showers
and thunderstorm are expected to develop in the heat of the day.
With the trough, somewhat diminished activity could linger into the
overnights.  The trough may pass to the south early next week. This
would allow drier air to move in from the north, helping to cut
precipitation chances, especially for SE GA. Temperatures will be
near normal Saturday, then above for Sunday through Tuesday.

&&

.AVIATION...
(06Z TAFS)
Issued at 120 AM EDT Wed Aug 20 2025

Prevailing VFR with periods of MVFR due to passing showers moving
onshore, with the highest confidence of SHRA through 12z at SGJ
were VCSH and TEMPO were advertised. VCSH may need to be included
at CRG based on radar trends. NNE winds increase through the day
with gusts near 25 kts. Continued with PROB30 groups for JAX and
CRG for passing showers midday. Winds back WNW tonight and
decrease below 6 kts inland to 10 kts coast.

&&

.MARINE...
Issued at 120 AM EDT Wed Aug 20 2025

Northeast winds increase and seas continue to build today as Hurricane
Erin tracks north, remaining well offshore of the southeast
Atlantic coast. Erin will begin to track northeast tonight into
Thursday, with a trailing front across south Georgia. This front
will edge southward and linger over the local waters Friday into
the weekend, bringing an increase in shower and thunderstorms. An
extended period of Small Craft conditions will impact the local
waters through late Friday due to lingering swells. Seas are
expected to lower below Small Craft Advisory levels this weekend.

Rip Currents: High rip current risk for all local beaches through
Friday due to long period swells from Erin. High risk may need to
extended into Saturday for northeast Florida beaches.

Surf: High surf advisory remains in effect through Thursday as
breaker heights continue to build today to > 7 ft at local
beaches, peaking this evening into the 7-11 ft range. Given the
northerly wind fetch, the more vulnerable beaches will be from
Duval county southward to Flagler county for moderate beach
erosion. Breaker heights subside into the 5-8 ft range Thursday
with minor beach erosion will be possible during the early evening
high tide Thursday.

Coastal/Tidal Flooding: Increasing astronomical tides during the
upcoming new moon (8/23) combined with increasing NNE winds, and
building swells from Hurricane Erin will continue to increase
local tidal levels through the day, with peak inundation expected
this evening along the Atlantic coast around high tide, which is
around 8 pm EDT. Latest guidance continued to indicate Minor stage
tidal/coastal flooding inundation of 1.7 - 2 feet above the Mean
Higher High Water (MHHW) datum. A Coastal Flood Advisory is in
effect today from 5 pm EDT to 11 pm. Elevated tidal levels will
extend to the Intracoastal Waterway (ICCW). Strengthening
northerly winds will likely also raise water levels within the St.
Johns River today, with a few location south of the Buckman
Bridge rising into action stage around high tide tonight (Wed
night) to 1-1.5 ft above MHHW, which is mostly below minor flood
levels.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  93  73  95  73 /  10  10  30  40
SSI  91  77  94  77 /  20  10  20  40
JAX  93  75  97  76 /  30  10  40  30
SGJ  90  76  94  76 /  40  10  40  30
GNV  94  75  95  75 /  20  10  50  20
OCF  93  76  93  76 /  20  20  70  20

&&

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

     High Surf Advisory until 2 AM EDT Friday for FLZ124-125-138-233-
     333.

     Coastal Flood Advisory from 5 PM this afternoon to 11 PM EDT
     this evening for FLZ124-125-138-233-333.

GA...High Rip Current Risk through Friday evening for GAZ154-166.

     High Surf Advisory until 2 AM EDT Friday for GAZ154-166.

     Coastal Flood Advisory from 5 PM this afternoon to 11 PM EDT
     this evening for GAZ154-166.

AM...Small Craft Advisory until 4 AM EDT Friday for AMZ450-452-454.

     Small Craft Advisory until 8 AM EDT Saturday for AMZ470-472-474.

&&

$$