147
FXUS62 KJAX 131806
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
206 PM EDT Sun Sep 13 2026

.KEY MESSAGES...

For the latest NE FL and SE GA Daily Key Messages please visit:
https:/www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

- Moderate Rip Current Risk all Local Beaches Today and Friday.
  High Surf and High Risk of Rip Currents

- Daily Heat Index up to 107 through Sunday

- Daily Afternoon & Evening Thunderstorms. Main Hazards: Locally Heavy
  Rain, Lightning & Gusty Winds Up to 40-50 mph

&&

.NEAR TERM /THROUGH TONIGHT/...
Main Highlights This Period:

- Frequent Lightning, Strong Gusts (30-50 mph), and Localized Heavy
  Rain possible with Strong, Isolated Thunderstorms this Afternoon,

- Highest Thunderstorm Chances Along I-95 Corridor, Mainly NE FL

- Heat Index Near Heat Advisory Today

- Locally Dense Fog for Suwannee Valley/I-75 Corridor Monday Morning


The big picture remains the same, with dry northwesterly flow,
associated with a shearing/dampening shortwave, flattening upper
ridging and sending drier air into the interior areas SE GA.
Eastward and south into NE FL, there is a higher chance (30-60%) of
thunderstorms this afternoon and early evening. The primary focus
for convection will once again be along the I-95 corridor with a
near west-to-east steering flow in place acting the slow the
Atlantic sea breeze and St Johns River breeze from advancing
inland/westward.

In the midst of pooled moisture ahead of the associated shortwave
trough has provided a near-saturated thermo profile this morning,
with measured precipitable water at 2.36". While there has been some
slight cooling the in upper levels, which could support more
frequent or excessive lightning, warming in the mid levels has also
occurred and is contributing to weaker lapse rates and potential
energy for thunderstorms through the rest of the afternoon.

That said, primary thunderstorm hazards continue to be frequent
lightning, gusty outflow winds, and localized flooding. Timing with
CAMs has been relatively solid, indicating expanding shower
development through 2 PM followed by scattered thunderstorm
potential increasing thereafter as mesoscale boundaries and outflows
interact along the I-95 corridor. Afternoon convection will begin to
settle this evening with the loss of diurnal heating as activity
generally develops southward.

A surface trough and moisture situated near the I-10 corridor
tonight may lead to patchy to areas fog formation during the predawn
hours Monday, especially across the Suwannee Valley and I-75
corridor where locally dense fog may develop by daybreak.

Temperatures hot again today and up to 2-4 deg above seasonal
averages, with heat indices up to 104 to 108. Lows tonight in the
lower to mid 70s.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
Main Highlights This Period: (Monday through Tuesday night)

- Thunderstorm chances Monday over NE FL, and over eastern counties
of SE GA and NE FL Tuesday

A trough of low pressure will be over the area on Monday. North of
this trough over SE GA, drier air will moving into the region. With
the drier air moving in precipitation chances will be largely
limited to NE FL.

This trough will dissipate as it sinks to the south Monday night.
Strong high pressure will build to the northeast Tuesday and Tuesday
night. As the high builds to the northeast, a surge of winds will
move south across the local coastal waters. Elevated winds can be
expected along the coast of SE GA and NE FL, and even further inland
across NE FL, due to orientation of the flow. An inverted trough is
expected to develop Tuesday along the coast, which will help produce
convection, mainly over eastern counties.

Temperatures will trend above average this period.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
Main Highlights This Period: (Wednesday through Sunday)

- Daily chances for thunderstorms, with greatest chance near the
coast Wednesday and Thursday


Strong high pressure will remain centered to the northeast
Wednesday, with an inverted trough along the coast. This pattern
will continue the elevated winds across the area, especially at the
coast. Precipitation chances will be greatest along the coast due to
convergence associated with inverted trough.

The high to the northeast will weaken Thursday, as troughing remains
along the coast. With the ridge weakening, the winds will be
lighter. The weakening ridge will also allow precipitation to spread
further inland through the day.

Another high will build to the north over the weekend.

Temperatures will trend around average this period.

&&

.AVIATION /18Z SUNDAY THROUGH 18Z MONDAY/...

Isolated thunderstorms ongoing will expand through 20z with
scattered coverage likely along the I-95 corridor through 00z,
bringing temporary visibility restrictions and the possibility of
gusty and erratic outflow winds. Outside of thunderstorm and outflow
influence, winds will favor a westerly direction at or below 10
knots with the exception of KSGJ and KSSI where the sea breeze will
shift wind southeasterly by 19z. After convection wanes this
evening, VFR conditions are predominantly expected through Monday
morning for coastal terminals. However, at inland terminals, KVQQ
and KGNV, with around a 20-30% chance of LIFR low stratus around 09-
12z Monday morning.

&&

.MARINE...

Offshore winds will continue across the area waters today and on
Monday, except for a sea breeze which will shift winds to the
southeast and south during the afternoon hours. Another good chance
of a couple of strong thunderstorms this afternoon and evening.
Strong gusty winds and very heavy rainfall will accompany the
stronger storms. On Monday, less thunderstorm activity is expected
and likely be limited to northeast Florida nearshore waters. From
Tuesday through Thursday, a strong northeast wind surge will bring
small craft advisory conditions, rough seas, and numerous showers
and a few thunderstorms over the area waters. Improving conditions
are expected by Friday as onshore winds weaken and seas gradually
lower.

Rip Currents: Prevailing offshore winds (except for an afternoon
sea breeze) and weak easterly swells will keep a low-end moderate
risk of rip currents in effect the next couple of days. By Tuesday,
strengthening northeast winds and building surf combine to lead to
dangerous surf and a high rip current risk area beaches during
through at least Thursday.

&&

.FIRE WEATHER...

Weak troughing over the area will dissipate through Monday. Strong
high pressure will build to the the northeast Tuesday and remain
through Thursday, with an inverted trough developing along the
coast. Winds will be elevated during the period from Tuesday through
Thursday, especially at the coast. The high will weaken Friday,
with another strong high building to the north over the weekend.

Daily thunderstorm chances this period, with greatest chances closer
to the coast this period.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  92  73  94  73 /  10  10   0   0
SSI  91  77  92  79 /  20  20   0   0
JAX  92  75  93  75 /  40  20  10   0
SGJ  91  76  91  76 /  40  30  10  10
GNV  92  74  93  74 /  40  20  40  10
OCF  92  75  93  74 /  50  20  50  20

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
MARINE...None.

&&

$$