536
FXUS62 KJAX 042337
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
737 PM EDT Thu Sep 4 2025

...New UPDATE, AVIATION...

.UPDATE...
Issued at 729 PM EDT Thu Sep 4 2025

Forecast remains on track through tonight and into Friday
morning. No major updates are required at this time.

&&

.NEAR TERM...
(Today through Tonight)
Issued at 155 PM EDT Thu Sep 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

Unseasonably dry weather remains in place today, with only
isolated to widely scattered showers and perhaps a thunderstorm
developing over north central Florida and Flagler county this
afternoon and evening. Tonight, calm winds and clear skies will
allow for some patchy fog formation pre-dawn over inland
locations. Low temperatures will dip into the mid to upper 60s
over inland southeast Georgia, and low 70s elsewhere.

&&

.SHORT TERM...
(Friday through Saturday night)
Issued at 155 PM EDT Thu Sep 4 2025

Weak high pressure ridge will remain over the forecast region on
Friday with some subtle moisture advection coming up from the
south that could support a few showers or a storm over north
central FL. Based on latest NBM and CAM models, made some slight
adjustment downward to the POPs. Should be mostly dry again Friday
night with some patchy fog possible inland areas with lows in the
mid 60s to lower 70s. Mid 70s possible at the coast.

Saturday, we begin to see larger changes as deeper moisture existing
over south and central FL begins to shift northward as deep layer
mean flow transitions from easterly on Friday to southerly on Saturday.
PWATS rise to about 2 inches over the southern most zones on Saturday.
This combined with daytime heating and sea breezes may kick off
scattered showers and storms in the afternoon. Quite more limited
chances toward I-10 at 20 percent, and then silent POPs for southeast
GA.

Model guidance shows plenty of sun and increased 1000-500 mb thickness
this period. This again suggests warm temps once again in the lower
90s inland and upper 80s at the coast. Heat indices expected to
be in the upper 90s to lower 100s. Lows will trend upward a bit to
the upper 60s and then mostly lower 70s as we begin to see more
moisture and additional clouds on Saturday and Saturday night.
Patchy fog is included for Saturday morning mainly inland areas
due to light winds and adequate sfc moisture.

&&

.LONG TERM...
(Sunday through next Thursday)
Issued at 155 PM EDT Thu Sep 4 2025

Another unseasonable cool front will be dropping into the northern
zones on Sunday and Sunday afternoon which could spark some weak
convection, while some lingering in moisture continues across the
southern most zones and also were a weak boundary is evident in
guidance, oriented west-east. Overall, most areas stay dry but
best chances of any rain will likely be over northeast FL, but
even so only about 30-40 percent at this time for mainly afternoon
showers or storms.

From Sunday night into early next week, the cool front moves into
the region as moderate high pressure system takes hold over the
Ohio Valley area at about 1028 mb. The pressure gradient between
the high and broad low pressure troughing over the FL peninsula
will result in increasing northeasterly low level flow, ushering
in a moist maritime airmass into the forecast area for the
beginning of next week.

This should set us up with another nor`easter once again. The
surge and duration of the event looks quite similar to the last
few days. Anticipate unsettled, gloomy and cooler conditions as
stratocumulus and convergent bands of showers push into the coast.
Flood rain risk initially should be low given the several days of
preceding dry conditions. Key messages are higher surf, dangerous
and frequent rip currents, beach erosion, and possibly minor coastal
flooding, and given that the full moon on 9/7 elevates the tide
levels already. In addition, local heavy rainfall is probable for
the coastal northeast FL area from Nassau county to Flagler county,
but possibly including portion of Clay and Putnam counties. Chances
of rainfall greater than 2 inches is about 30-40 percent at this
time starting on Monday. Temps will trend down to the 80s most
areas and lows in the mid to upper 60s well inland over southeast
GA, and lower to mid 70s elsewhere.

&&

.AVIATION...
(00Z TAFS)
Issued at 729 PM EDT Thu Sep 4 2025

VFR conditions will continue through the forecast period with
winds becoming more mild overnight and then rebuilding from out
of the NE-E on Thursday. Chances for early morning mist to be
reported by VQQ and GNV in the early morning hours.

&&

.MARINE...
Issued at 155 PM EDT Thu Sep 4 2025

A frontal boundary currently stalled near the Florida Keys will
lift slowly northward through the Florida peninsula on Thursday
and Friday, with another weak low pressure center developing along
this front east of Cape Canaveral. This feature will likely
maintain generally light onshore winds across our local waters
through the weekend. A frontal boundary will then approach our
region from the northwest on Sunday, with this front then stalling
across our local waters on Monday, bringing increasing chances
for showers and thunderstorms. Onshore winds will increase and
seas will build early next week as strong high pressure building
over New England wedges down the southeastern seaboard.

Rip currents: Moderate rip current risk at the northeast Florida
and southeast Georgia beaches through the weekend, with a high
risk possible early next week as onshore winds strengthen.

&&

.HYDROLOGY...
Issued at 159 AM EDT Thu Sep 4 2025

On the hydro side, northeasterly wind surge will trap tidewater
in the upper St Johns River potentially elevating high tide south
of Jacksonville. Overall, levels look to be coming down as the
northeast flow weakens and rainfall is very limited now with max
values of about 1.4 to 1.5 ft MHHW and are at just a couple of
sites. Astronomical influence is fairly limited before the full
moon on Sunday Sept 7th.

But the upcoming full moon in concert with the onshore flow and
expected rainfall next week will probably result in elevated
water levels both along the coast and within the St Johns River
Basin. This could start as early as Monday but more likely on
Tue-Thu.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  66  92  68  92 /   0   0   0  10
SSI  73  87  74  87 /   0   0   0  10
JAX  71  91  72  92 /   0   0   0  20
SGJ  75  89  76  89 /   0  10  10  30
GNV  69  94  71  94 /   0  10   0  30
OCF  72  92  73  92 /  10  20  10  40

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 5 AM EDT Saturday for FLZ038-132-
     137-633.

GA...None.
AM...None.
&&

$$