336
FXUS62 KJAX 041144
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
744 AM EDT Fri Jul 4 2025

...New AVIATION...

.NEAR TERM...
Issued at 207 AM EDT Fri Jul 4 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

Synopsis...A surface front was stalling near the FL-GA state-line
early this morning with some moisture pooling near and south of
the front developing low stratus and occasional fog. A broad
surface low was observed in satellite early this morning, about
100 NM east of the First Coast. In the upper levels, a broad
trough was slowly carving southward across the eastern CONUS while
mean layer 1000-500 mb steering flow was weak from the NNE less
than 10 kts with streamlines showing a broad cyclonic flow near
and just east of the FL peninsula. Satellite derived precipitable
water (PWAT) was over 2 inches across NE FL and coastal SE GA,
while a sliver of lower than average PWAT < 1.7" was across our
far NW GA zones near the Altamaha and Ocmulgee River Basins (daily
median PWAT for this date is 1.75 inches).

Forecast...Showers and isolated storms will break out late
morning across coastal SE GA and across portions of NE FL
generally south of the I-10 corridor near and south of the
lingering frontal zones as onshore ENE winds develop a stronger
east coast sea breeze. Convection will blossom as the east coast
sea breeze shifts inland across SE GA, especially for locations
ESE of a Jesup to Waycross to Homerville line and across much of
NE FL where deeper moisture (PWAT 1.9-2.2 inches) lingers while
drier air toward the Ocmulgee River basin brings more isolated to
scattered afternoon showers and storms. The higher rain chances
of 60-80% will focus across NE FL this afternoon into the early
evening, especially for locations along and south of the I-10
corridor where boundary mergers occur under increasing NNE
steering flow of 10-15 kts. As has been the case, the main
convective concern will be localized heavy rainfall which could
bring brief flooding as well as gusty downburst winds in merging
cells given weak shear, warm temps aloft and weak lapse rates.
Rainfall will generally tapper off across inland areas this
evening through midnight, while coastal showers and isolated
storms increase over the adjacent coastal waters and could skirt
near the coastal counties through daybreak Saturday morning as the
coastal low farther offshore further develops.

Temperatures will trend from the upper 80s at the coast to lower
90s well inland, near to slightly below average values. Muggy and
mild overnight lows will range in the low to mid 70s inland to
upper 70s coast.

&&

.SHORT TERM...
(Saturday through Sunday night)
Issued at 207 AM EDT Fri Jul 4 2025

Moist low pressure air mass is anticipated to be over and near the
forecast area, situated ahead of the stalled frontal boundary for
the start of this weekend, leading to widespread showers and
storms forming during daytime hours through the period with
intensity and dispersion depending on the positioning of the air
mass and upper level shortwaves passing through the region. High
temperatures this weekend will rise into the upper 80s and lower
90s with overnight low temperatures dropping down into the lower
70s over inland areas and in the mid 70s along the coastline.

&&

.LONG TERM...
(Monday through Thursday)
Issued at 207 AM EDT Fri Jul 4 2025

Pattern for diurnal showers on storms is expected to carry over
into next week with convection developing in association with sea
breeze boundaries and areas of convergence, however the timing and
placement of the potential low pressure cyclonic system forming
ahead of the decaying frontal boundary still carries some
uncertainty with the NHC forecast currently showing a 60% chance
for formation by the end of the week, with a 40% of formation by
the beginning of the week. Daytime high temperatures will be
slightly above average with temperatures expected to be in the low
to mid 90s.

&&

.AVIATION...
(12Z TAFS)
Issued at 742 AM EDT Fri Jul 4 2025

Areas of IFR and LIFR for inland areas with fog and stratus across
parts of northeast FL and southeast GA. Closer to the coast, mainly
MVFR conditions from early morning stratus and fog. These conditions
will lift over the next couple of hours and then expect scattered
to broken MVFR cumulus, with the MVFR cigs occurring at times until
at least 16Z. Scattered showers and storms expected by early to
mid afternoon, with storms generally heading southward about 10-15
kt. We have PROB30 TSRA groups for now for most of the TAFs with
MVFR conditions indicated. Showers and storms will be fading and
then dissipating after 22z/23z. Another potential period of low
stratus and some fog after midnight and was conservative showing
that chance given the uncertainty.

&&

.MARINE...
Issued at 207 AM EDT Fri Jul 4 2025

A front will stall and linger over the local coastal waters today
through the weekend. An area of weak low pressure will develop
along the frontal boundary late tonight or Saturday, and the low
is expected to meander over the coastal waters through Sunday.
Elevated winds and seas could reach Small Craft Advisory
conditions mainly across Georgia waters this weekend. The low is
expected to lift northward away from the local waters late Sunday
or Monday. The National Hurricane Center is monitoring this system
to see if the low will become a tropical or subtropical
depression. As the low departs Monday into Tuesday, a weak trough
will linger across Georgia as high pressure builds northward
across the Florida peninsula.

Rip Currents: A moderate rip current risk is expected through the
holiday weekend with a low high risk possible for SE GA beaches
Saturday if the coastal low approaches the local coast. Elevated
surf will generally be 2-3 ft with 3-4 ft breakers possible along
the SE GA Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  92  72  88  71 /  30  10  70  20
SSI  87  76  85  75 /  40  30  80  30
JAX  90  74  88  73 /  60  30  90  30
SGJ  88  74  87  73 /  60  30  90  30
GNV  92  72  90  71 /  70  20  90  20
OCF  91  73  88  73 /  80  30  90  30

&&

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

$$