182
FXUS62 KJAX 280623
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
223 AM EDT Thu Aug 28 2025

...ISOLATED HEAVY RAINFALL FLOOD THREAT EXPECTED THROUGH THE
WEEKEND...
...New NEAR TERM, SHORT TERM, LONG TERM, AVIATION, MARINE...

.NEAR TERM...
(Today through Tonight)
Issued at 200 AM EDT Thu Aug 28 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

The frontal boundary will recede to the north over the course of
the day as high pressure moves toward the northeast, allowing for
a more moist westerly flow to replace the drier air over the
forecast area with PWAT levels gradually rising to be 2 inches and
above by late tonight. Early morning showers and possible thunderstorms
for coastal areas with a majority of the convection expected to
occur over the waters. Afternoon and evening showers and storms
will become more prevalent today with the most widespread
convection building over areas along and south of the I-10
corridor with storms becoming more dispersed overnight, with a
potential for near shore convection developing along coastal
northeast Florida before sunrise. High temperatures for today will
rise into the lower 90s and upper 80s for inland areas and in the
mid 80s along the coast. Overnight low temperatures will drop
down into the lower 70s over inland areas and in the mid 70s near
the St Johns River and along the Atlantic shoreline.

&&

.SHORT TERM...
(Friday through Saturday night)
Issued at 200 AM EDT Thu Aug 28 2025

Frontal boundary will be located across northern FL Friday morning
and rich moisture (PWATs of about 2 inches) is shown by models
overlapping the region. In addition, at least a couple of
shortwave impulses will be riding east- southeast aloft helping to
improve synoptic scale lift over the region. Morning time will
see most of any convection along the coast where convergence is
maximized between broad low pressure over the northeast Gulf, the
northeast flow behind the front over southeast GA, and far
northeast FL, and instability over the warm Atlantic Waters.
Locally heavy precip will be possible during the morning hours
mainly coastal northeast FL. By the afternoon, with better lift
moving into the forecast area, more precip will break out over
inland zones with the I-75 corridor more favored, while the coast
will see some reprieve from some of the heavy bands of
showers/storms. In all areas, isolated storms may be strong, with
some organization possible given shear values of about 25 kt
coupled with MLCAPE of about 1500-2500 J, helped by cooler temps
aloft as well at about -7C to -8C.

Friday Night, the location of the diffuse front is in question, but
looks to be across north central FL at this point. Deep moisture
remains over the area with PWATs just a touch lower, while we
continue to see ripples of shortwave energy move across AL/GA/ and
north FL which will continue continue the unsettled weather to
start the weekend. Locally heavy rainfall will continue to be a
concern, though the intensity overnight will likely wane with loss
of heating. The exception may be along the coastal areas where
onshore flow may result in locally heavy bands of showers or
storms.

Saturday...the frontal boundary will be sagging southward over
north or north central FL with shortwaves still rotating around
the base of the trough over the southeast CONUS. We should continue
to see quite abundant cloud cover along with numerous to widespread
precip during the day, with locally heavy rainfall possible, along
with a low chance of strong storms if enough heating can be gained.
Sat night, there is disagreement in model guidance with where front
may extend over the region, but generally high pressure remains
to our north while we continue in east-northeast flow. ECMWF shows
a wave of low pressure pushing east-southeast from the western FL
panhandle to the Gulf. For now, expect the chance of rain to continue
Saturday night, but not expecting any widespread heavy rainfall
at this time.

The Weather Prediction Center (WPC) does place the area under a marginal
risk (1/5) for excessive rainfall for most locations from Friday through
Sunday, which may change over the coming days pending the exact
position of the frontal zone.

Max temps for Friday mainly mid 80 to near 90, and a bit lower by
Saturday. Lows mainly in the upper 60s to lower 70s, with some mid
70s likely along the coast.

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 200 AM EDT Thu Aug 28 2025

Any possible wave of low pressure along the front over the Gulf
or the FL peninsula on Sunday is expected to pivot east-southeast
then eastward, while high pressure attempts to build in behind it
late Sunday into early next week. Locally heavy rainfall is still
possible on Sunday over northeast FL where the deeper moisture
will be located. Long range guidance is still out of sorts in some
form of agreement early next week, but early indications are
generally for a downward trend in PoPs as the base of the upper
trough sinks further into the southeast states and tries to pull
in some drier air from the north/northwest. As of now, looks as
though northeast FL will have the highest coverage for PoPs early
Mon-Wed as the frontal boundary sinks further south and a ridge of
high pressure tries to build in from the north. Predominant
breezy northeast flow looks probable Monday to Tuesday.
Temperatures trend near to slightly below normal Sunday to
Tuesday, then a bit warmer by Wed.

&&

.AVIATION...
(06Z TAFS)
Issued at 200 AM EDT Thu Aug 28 2025

Early AM showers and storms forming along coastal areas and potentially
affecting Jax metro sites until around 10-12z. More widespread
convection will build in the afternoon hours with the highest
likelihood for convection occurring over northeast Florida
beginning around 18-20z and then dispersing and moving offshore
overnight by around 02-04z. Diurnal sea breeze will affect coastal
and Jax sites through around 14-20z and then receding with mild
and variable winds for inland areas through the end of the
forecast period.

&&

.MARINE...
Issued at 200 AM EDT Thu Aug 28 2025

The stalled frontal boundary will continue to slowly lift northward
as Atlantic ridging builds into south Florida. A weak low will
form today as northeast to easterly flow north of the front
creates convergent showers and isolated thunderstorms. High
pressure to the north will reform more to the northeast as the
front continues to lift back northward. The front will linger
across the local waters Friday and into the weekend with a return
of elevated shower and thunderstorm chances through the upcoming
weekend. Another cold front will move down the coast early next
week bringing elevated northeasterly winds and seas.

Rip Currents: Moderate risk for area beaches today and Friday.

&&

.HYDROLOGY...
Issued at 200 AM EDT Thu Aug 28 2025

Scattered to numerous showers and some storms expected to develop
through the day with heaviest rainfall potential expected east of
Highway 301, but especially along the coast this morning. Rainfall
chances remains elevated into Friday and over the weekend. However,
the threat of numerous to widespread rainfall flooding remains
toward the low chance range, for the moment, so a flash flood
watch is not anticipated at this time. Nonetheless, poor drainage
areas and locations near the coast and the St Johns River Basin
are more susceptible to localized rainfall flooding.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  89  68  85  68 /  20  10  30  40
SSI  86  76  85  74 /  30  10  40  40
JAX  89  73  88  72 /  50  10  60  40
SGJ  89  74  87  75 /  60  30  60  40
GNV  91  72  89  72 /  60  10  50  30
OCF  91  72  89  73 /  60  10  60  20

&&

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

$$