Area Forecast Discussion
Issued by NWS Jacksonville, FL
Issued by NWS Jacksonville, FL
128
FXUS62 KJAX 230723
AFDJAX
Area Forecast Discussion
National Weather Service Jacksonville FL
323 AM EDT Wed Sep 23 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
- Scattered to Numerous Showers and a Few Embedded Thunderstorms
Today, Mainly for Locations Along and East of U.S. Highway
301. Locally Heavy Downpours Possible at Coastal Locations.
- Strengthening Onshore Winds and Increasing Marine and Coastal
Hazards Thursday through Saturday. High Risk for Rip
Currents and Rough Surf Expected at Area Beaches. Frequent
Wind Gusts of 40 mph Possible at Coastal Locations on
Thursday. Minor Coastal Flooding Around Times of High Tide
Beginning Thursday Evening Along the Atlantic Coast.
&&
.NEAR TERM /THROUGH TONIGHT/...
Main Highlights through Tonight:
- Isolated Thunderstorms this Afternoon, with Locally Heavy
Rainfall Possible at Coastal Locations.
- Strengthening Onshore Flow and Increasing Beach Hazards Today
and Tonight.
Low pressure will organize and strengthen east off the Carolinas
today and tonight. As this occurs, an upper trough digs into the
southeast states tonight, pushing the backdoor front to our
northeast southward through the region and into Central Florida
by Thursday Morning with much stronger high pressure building
down the southeast coastline accordingly.
The result will be a stronger northeasterly onshore flow
building across our area today, with numerous showers and
isolated thunderstorms pushing onshore throughout the day with
heavy downpours at times. Most rainfall will be found closer to
the coast, though chances for showers will expand further inland
throughout the day, especially with a little bit of diurnal
enhancement inland. Despite a bit of enhancement, much drier air
aloft should limit most thunderstorm coverage today, though a
few isolated storms will be possible which could produce some
gusts a bit stronger than the gradient flow.
Overall, drier and cooler conditions will be present over
southeast Georgia, especially inland GA. While the strongest
conditions and most hazardous beach/marine conditions will
generally occur after the near term forecast period, winds build
to the 10-20 mph range with gusts as high as 25-30 mph, which
will return a high rip current risk to all area beaches today.
The developing maritime flow will nudge high temps down a few
degrees overall, though today will still be a transition day of
sorts, and therefore mid to upper 80s will remain common, though
a few readings up to 90 will be possible inland.
The northeasterly surge will build further tonight behind the
front as high pressure ridging pushes southward, especially
towards the coast. Winds will remain elevated area-wide
overnight to prevent any fog, though periods of coastal showers
will continue through the overnight hours tonight where onshore
winds increase to near or stronger levels later in the night
after a slight lull during about the first half of the night.
Low temps will remain mild in the low 70s over northeast FL and
the coast, though mid to upper 60s will be expected across
inland GA as some cooler and drier air starts to filter in.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
Main Highlights This Period:
- Strengthening North-Northeasterly Winds Will Bring Increasing
Marine and Coastal Impacts from Thursday through Friday.
- Much Cooler and Gradually Drier Conditions Expected.
- Minor Coastal Flooding Likely Around Times of High Tide Along
the Atlantic Coast Beginning on Thursday Evening. Tidal
Flooding Possible within the St. Johns River Basin Beginning
on Friday.
Longwave troughing aloft will dig and sharpen over the eastern
third of the nation as ridging amplifies over Texas, the
Southern Plains, and the lower Mississippi Valley. Embedded in
this longwave, a potent shortwave trough pivoting across the
southern Appalachians and the Carolinas on Thursday and Thursday
evening will invigorate a developing surface low pressure
center located between Bermuda and the Mid-Atlantic coast, with
this feature deepening and retrograding slowly westward by
Friday afternoon and night. Meanwhile, strong high pressure
building over southeastern Canada and New England will push a
"backdoor" cold front southward down the FL peninsula on
Thursday, with this surface ridge wedging down the southeastern
seaboard and tightening our local pressure gradient, creating
strengthening northerly winds along the I-95 corridor, with
breezy conditions spreading inland by the mid-morning hours.
North-northeasterly winds will peak from the mid-morning through
early evening hours at coastal locations, where sustained speeds
of 20-25 mph will frequently gust to 35-40 mph. A Wind Advisory
may be required for coastal locations on Thursday and Thursday
evening. These winds will advect a much drier air mass into our
area as the day progresses, with PWATs falling to near or below
1.5 inches region-wide by the late afternoon hours. Bands of
showers and isolated embedded thunderstorms developing near and
just behind the southward moving frontal boundary could bring
waves of downpours to coastal northeast FL and possibly north
central FL, especially during the morning hours before the drier
air mass overspreads the rest of our area. Otherwise, plenty of
low and mid level cloud cover and strengthening cool air
advection will keep highs in the upper 70s to lower 80s, with
mid 80s possible across north central FL.
A cooler and drier air mass will continue to funnel into our
area on Thursday night as low level flow backs to a more
northerly direction. Breezy to windy conditions will continue
along the I-95 corridor and points eastward overnight, and a
showers will remain possible, mainly for coastal northeast FL .
Clearing skies and a light northerly breeze will drop lows to
the lower 60s for most of inland southeast GA and the Suwannee
Valley, and coastal locations in southeast GA will likely fall
to the mid 60s despite breezy conditions prevailing. Lows will
drop to the mid to upper 60s for north central FL, while breezy
to windy conditions keep lows closer to 70 along the northeast
FL coast.
Our local pressure gradient will remain tight on Friday, with
breezy to windy conditions expected at coastal locations.
Morning marine stratocumulus and continues cool air advection
should keep coastal highs in the upper 70s. Breezy north-
northeasterly winds will otherwise advect an unseasonably dry
air mass into our area, allowing skies to clear from northwest
to southeast and dewpoints to fall into the 50s across inland
southeast GA, while values fall to the upper 50s by Friday
afternoon across the Suwannee Valley and fall through the 60s
elsewhere. Highs at inland locations will generally reach the
upper 70s to lower 80s, except mid 80s for locations south of
Gainesville. Winds will then decouple on Friday evening at
inland locations, allowing for radiational cooling overnight,
dropping lows to the low and mid 50s for inland southeast GA,
with upper 50s and lower 60s elsewhere inland and mid to upper
60s at coastal locations, where breezy northerly winds will
continue overnight.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
Main Highlights This Period:
- Marine and Coastal Impacts Continue on Saturday as North-
Northeasterly Gradually Subside.
- Seasonably Cool Weather on Saturday and Saturday Night
Gradually Moderates from Sunday through Early Next Week.
- Minor Coastal Flooding Likely Around Times of High Tide Along
the Atlantic Coast through Saturday. Minor Tidal Flooding
Possible within the St. Johns River Basin this Weekend and
Early Next Week.
Deep troughing aloft along the U.S. eastern seaboard will become
negatively tilted, resulting in an intense coastal storm
meandering along the Mid-Atlantic and then New England coasts
this weekend through early next week. This weather pattern will
allow for our local pressure gradient to only slowly loosen on
Saturday, with breezy north-northeasterly winds persisting for
locations east of I- 95 in northeast FL, where highs will again
only climb to around 80 despite abundant sunshine. Dry
northwesterly flow aloft across the southeastern states should
drop dewpoints to the mid and upper 50s across northeast and
north central FL by Saturday afternoon, and plenty of sunshine
will combine with this dry air mass to allow highs at inland
locations to climb to the low and mid 80s.
Our local pressure gradient will loosen substantially by
Saturday night and Sunday as the coastal storm meanders
northward, with fair skies and decoupling winds at inland
locations early on Saturday evening allowing lows to fall to the
50s for most of inland southeast GA and northeast FL, ranging
to the lower 60s for inland north central FL. A light
northwesterly breeze will drop coastal lows to the mid 60s by
early Sunday morning.
Flow aloft will become zonal across our region on Sunday, with a
moisture starved shortwave trough potentially increasing high
altitude cloud cover somewhat on Sunday and Sunday night. An
unseasonably dry air mass will otherwise linger through Monday
area- wide, with slowly rising heights aloft allowing highs to
rebound to the low and mid 80s on Sunday and the mid to upper
80s on Monday. The dry air mass, generally fair skies and weak
high pressure over our area will allow for additional nights of
radiational cooling on Sunday and Monday, with inland lows
falling to the upper 50s and lower 60s on Sunday night,
moderating slowly to the low to mid 60s on Monday night. Coastal
lows will generally fall to the 65-70 degree range.
High pressure will then shift offshore on Tuesday, allowing for
gradually increasing moisture levels from south to north as low
level flow becomes easterly. These onshore winds and perhaps a
weak coastal trough that will lift northward as a pseudo warm
front could bring a few showers to the I-95 corridor in
northeast FL as well as north central FL by Tuesday afternoon
and evening. Highs on Tuesday will again climb to the mid and
upper 80s inland and the low to mid 80s at coastal locations.
Lows on Tuesday night will continue to gradually moderate, with
mid to upper 60s inland and lower 70s at coastal locations.
&&
.AVIATION /06Z WEDNESDAY THROUGH 06Z THURSDAY/...
Isolated showers will move towards the coast through the rest
of the morning hours, though chances overall do not appear high
enough for any restrictions. At inland terminals, expecting
winds to be light enough for some FG and low stratus to form
once again, mainly in the MVFR range though have included TEMPO
IFR at VQQ accordingly. Northeasterly onshore flow will
increase throughout the day today from north to south as a
frontal boundary moves through. This will also increase SHRA
coverage, though TSRA chances are too low to include any mention
at this time as probs are under 10 percent. The main impacts
with the developing surge will be predominantly MVFR ceilings
and the breezy winds, which for the most part will remain above
10 knots beginning this afternoon and through the rest of the
forecast period.
&&
.MARINE...
Low pressure will strengthen well to the northeast of the region
through the end of the week, tracking further to the north of
the area through the weekend. High pressure will build down the
eastern US coastal states Wednesday causing a backdoor cold
front to sweep southward. The gradient between the high, and the
front trailing from the low to the northeast, will result in
enhanced northeasterly winds and waves beginning later today and
lasting through at least Friday. A period of Gale conditions
will be possible Thursday into Thursday night. These conditions
ease this weekend as high pressure weakens and the
aforementioned low pulls further away from the area.
Rip Currents: Rip current risk will increase from north to south
today and into Thursday thanks to a northeasterly wind surge,
with a high risk expected at all beaches starting today. High
risk will persist through at least Friday, and remain elevated
through the upcoming weekend as rough and mostly short period
seas persist.
&&
.FIRE WEATHER...
- Elevated Nighttime Dispersions At Coastal Locations Tonight.
- Elevated Nighttime Dispersions Along the I-95 Corridor and
Coastal Locations on Thursday Night.
Scattered to numerous showers and thunderstorms are expected to
develop early this morning at coastal locations, with activity
then spreading south and westward across most of northeast and
north central FL by this afternoon. Shower activity will then
shift to the Interstate 95 corridor tonight through Thursday
evening before a drier air mass overspreads our entire area from
Friday through Monday. This drier air mass will drop minimum
humidity values to near critical thresholds across inland
portions of southeast Georgia by Sunday afternoon.
Northeasterly transport winds will gradually strengthen from
north to south today today, with breezy surface winds
developing along the I-95 corridor during the mid to late
morning hours and then spreading inland this afternoon. These
strengthening winds will create fair to good daytime dispersion
values. North-northeasterly surface and transport winds will
remain breezy at coastal locations tonight, creating elevated
nighttime dispersion values. North- northeasterly surface and
transport winds will continue to strengthen on Thursday and
Thursday night along the I-95, with breezy conditions
redeveloping at inland locations by mid-morning Abundant lower
cloud cover will keep daytime dispersion values in the fair to
good range despite breezy to windy conditions. Elevated
nighttime dispersion values are forecast to continue along the
I-95 corridor on Thursday night due to breezy surface speeds.
Breezy northerly surface and transport winds and decreasing
cloud cover on Friday at inland locations will create good
daytime dispersion values area-wide.
Fog Potential...Significant fog formation is not expected during
the next several days.
&&
.TIDES/COASTAL FLOODING...
Astronomical tides will rise through the weekend due to the
upcoming Full "Harvest" Moon that occurs on Saturday. A
northeast wind surge will overspread coastal locations through
Thursday will combine with the increasing astronomical tides to
create minor coastal flooding along the Atlantic coast from
Thursday evening through at least Saturday. Minor flooding will
be possible along the Atlantic coast beginning with the evening
high tide on Thursday, where water levels of 1.5 - 2.5 feet
above Mean Higher High Water (MHHW) are preliminarily forecast,
which will create mostly minor, nuisance type flood impacts.
Minor flooding will then expand to the St. Johns River basin
beginning on Friday and are expected around times of high tide
through the weekend and into next week, as rising astronomical
tides beyond the date of the Full Moon keep water levels
elevated, generally at 1-2 feet above MHHW during each tide
cycle for most locations within the basin.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 88 68 79 61 / 20 10 0 0
SSI 85 71 79 64 / 40 30 20 10
JAX 86 72 80 65 / 50 20 30 20
SGJ 85 74 81 71 / 60 40 60 30
GNV 89 71 85 66 / 40 10 20 0
OCF 91 73 86 68 / 40 20 20 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Risk for Rip Currents through late Saturday night for FLZ124-
125-138-233-333.
GA...High Risk for Rip Currents through late Saturday night for GAZ154-
166.
MARINE...Small Craft Advisory from 11 AM this morning to 8 PM EDT
Friday for AMZ450-470.
Small Craft Advisory from 6 PM this evening to 2 AM EDT
Saturday for AMZ452-454-472-474.
&&
$$