709
FXUS62 KJAX 090806
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
406 AM EDT Thu Oct 9 2025

...New NEAR TERM, SHORT TERM, LONG TERM, MARINE, FIRE WEATHER, HYDROLOGY...

.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

- Long Duration Nor`Easter Begins Today. Highest Water Levels of
  the Fall Season thus Far Expected along the Atlantic Coast on
  Friday and Saturday. Destructive Beach Erosion Possible at Area
  Beaches Friday through the Weekend. Moderate Tidal Flooding
  this Weekend within the St. Johns River Basin.

- Coastal Flood Watch for the Atlantic Coast and St. Johns River
  Basin from Friday Morning through Saturday Night. Gale Warning
  for Atlantic Waters this Afternoon through Saturday Night. High
  Surf & Wind Advisories for Coastal Locations this Afternoon
  through Friday.

- Heavy Downpours and Isolated Thunderstorms Along the I-95
  Corridor this Afternoon through Friday Night. Localized Flooding
  Possible, Especially at Coastal Locations if Downpours Coincide
  with High Tide.

&&

.NEAR TERM...
Issued at 406 AM EDT Thu Oct 9 2025

An approaching cold front will begin to cross into SE GA by the
early morning hours, push southward through NE FL by the later
part of the afternoon, and to the south of north central FL by
Tonight.

Onshore winds will begin to increase during the early morning
hours as the local gradient begins to tighten as coastal troughing
begins to develop along the FL/GA coastline. Elevated
northeasterly flow will bring winds in the 20 to 30 mph range by
the mid to late afternoon hours along coastal locations, with
gusts in the 35 to 45 mph range. These areas are already under
Wind Advisories beginning this afternoon and into the upcoming
weekend as the elevated winds are expected to persist over the
next couple of days. As this will coincide with the Full Moon and
higher tides, the onshore flow will bring the coastal hazards
threats of rip currents, coastal flooding, dangerous maritime
boating conditions, and rough surf heading this afternoon and into
the upcoming weekend.

The onshore flow will also bring showers onshore throughout the
day, with scattered coverage of showers across the area. Scattered
to numerous showers for coastal locations by the afternoon to
evening hours as some isolated to scattered embedded storms may
develop as the showers move onshore. Could see some heavy
downpours associated with any storms that do develop.

With the cold front moving through, highs will span from the upper
70s to mid/upper 80s. The cooler highs will all be across SE GA as
the front will have already passed through during peak heating
times, with the warmer highs located in NE FL as these locations
will be ahead of the front during peak heating. Lows for the more
inland locations will be in the upper 50s to lower 60s, with the
cooler lows along northern SE GA. Lows will be in the upper 60s to
lower 70s, while north central FL will be in the lower 70s.

&&

.SHORT TERM...
(Friday through Saturday night)
Issued at 406 AM EDT Thu Oct 9 2025

A potent shortwave trough diving southeastward from the Tennessee
Valley today will cutoff from the main flow over southern GA on
Friday, yielding cyclogenesis along the frontal boundary east of
Cape Canaveral by Friday evening. Meanwhile, strong high pressure
centered over coastal New England will gradually weaken and shift
eastward by Friday night as this low pressure center takes shape
over the Gulf Stream waters adjacent to our region. This weather
pattern will maintain a very tight local pressure gradient across
our area, and a drier air mass will advect across inland southeast
GA and the Suwannee Valley by Friday afternoon.

Strong coastal convergence will keep a threat for heavy rainfall
in place along the I-95 corridor on Friday and Friday night.
Strong onshore winds will combine with lingering high astronomical
tides from this week`s lunar perigee to produce widespread
moderate coastal flooding along the Atlantic coast and within the
St. Johns River basin (see "Hydrology" section below for details).
Cloud cover and cool air advection will keep highs in the 70s on
Friday, except around 80 for north central FL. Shower coverage
will taper off across inland southeast GA and the Suwannee Valley
on Friday afternoon and evening, with lower stratus clouds likely
lingering through the early morning hours on Saturday as moisture
wraps around the stacked cyclone off the southeastern seaboard.
Cool air advection will drop lows to the low and mid 60s on Friday
night at inland locations, ranging to 65-70 at coastal locations,
where strong wind gusts and waves of downpours will make for damp
and chilly weather.

The deepening, increasingly vertically stacked cyclone will then
lift slowly northward towards the Outer Banks on Saturday. North-
northeasterly winds will remain breezy at inland locations and
windy at the coast, with wrap-around showers likely along the I-95
corridor into the afternoon hours. A much drier air mass will
then overspread our region on Saturday night and Sunday as winds
shift to northerly with gradually decreasing speeds. Cloud cover
and gusty winds will again keep highs in the 70s at most
locations. Clearing skies on Saturday night will allow lows to
fall to the mid and upper 50s for inland locations along and north
of the I-10 corridor, while stiff northerly winds keep coastal
lows in the low to mid 60s.

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 406 AM EDT Thu Oct 9 2025

The vertically stacked gale center near the Outer Banks on Sunday
morning will continue moving slowly northward, impacting the
Delmarva region on Sunday night and then approaching the Mid-
Atlantic coast on Monday. This vertically stacked storm system
will provide deep northwesterly flow across our area, advecting a
dry and initially seasonably cool air mass across our region. This
drier air mass will scour out the wrap-around moisture and
lingering lower stratus clouds at coastal locations shortly after
sunrise, and plenty of sunshine for the balance of the day will
allow highs to climb to the lower 80s inland, with coastal highs
remaining in the upper 70s. Heights aloft will then rise early
next week Wednesday as ridging aloft expands from Texas eastward
along the northern Gulf coast, allowing for highs to climb to the
mid 80s inland on Tuesday and Wednesday, while onshore winds
developing during the afternoon hours keep coastal highs around
80. Nighttime lows will continue to fall to the 55-60 range
inland, ranging to the mid 60s at coastal locations.

&&

.AVIATION...
(06Z TAFS)
Issued at 142 AM EDT Thu Oct 9 2025

VFR conds and light winds with chances of MVFR stratus/fog at VQQ
in the 06-10Z time frame and in the 08-12Z time frame at GNV.
Surge of NE winds and MVFR CIGS/VSBYS with increasing rainfall
chances will begin at SSI in the 11-12Z time frame around 15Z at
the JAX metro TAF sites and to GNV by the 16-17Z time frame.
Shower chances begin to decrease along inland locations near 00Z.
CIGS will begin to trend lower towards IFR during the late TAF
period for inland areas.

&&

.MARINE...
Issued at 406 AM EDT Thu Oct 9 2025

A frontal boundary crosses into the GA waters during the predawn
hours this morning and pushes towards the FL waters by late this
morning to early afternoon hours. Northeast winds will quickly
strengthen as a coastal trough develops over the near shore
waters. Showers and embedded storms will begin to increase in
coverage through Friday. Small Craft Advisory conditions are
expected to develop this morning. A Gale Warning has been posted
from this afternoon through Saturday night. Low pressure will then
develop along the frontal boundary over the Gulf Stream waters
adjacent to our region on Friday, with this feature gradually
strengthening as it moves northward towards the Carolinas this
weekend. Strong north-northeasterly winds and building, very rough
surf will create dangerous conditions throughout our local waters
from Thursday night through early Sunday. Northerly winds will
gradually subside late this weekend into early next week, with
elevated seas also likely slow to subside across our local waters.


Rip Currents: High rip current risk across area beaches Today and
into the weekend with rough surf and deadly rip currents are
expected with the increased onshore flow.

&&

.FIRE WEATHER...
Issued at 406 AM EDT Thu Oct 9 2025

Northeasterly surface and transport winds will quickly strengthen
after sunrise from north to south today, with frequent surface
gusts of 35-45 mph expected this afternoon through Saturday
afternoon along the I-95 corridor. These strengthening winds will
counter increasing cloud cover and rainfall chances to create fair
daytime dispersion values, except across north central FL, where
good values are forecast. Strong northeasterly surface and
transport winds will prevail through Friday night, creating
elevated nighttime dispersion values, especially along the I-95
corridor. Scattered showers will continue along the I-95 corridor
through early Saturday afternoon before a drier air mass
overspreads our region on Saturday night and Sunday. Surface and
transport winds will shift to north-northeasterly on Saturday and
then northerly by Saturday evening. Windy conditions will create
fair to good daytime dispersion values on Friday, with good to
marginally high values forecast on Saturday and Sunday. Surface
and transport winds will then shift to northwesterly on Sunday,
with diminishing speeds expected at inland locations.

&&

.HYDROLOGY...
Issued at 406 AM EDT Thu Oct 9 2025

Water levels are expected to reach minor flood levels along the
Atlantic coast and within the Intracoastal Waterway (ICWW), and
the St Johns River Basin during times of high tide today as the
nor`easter begins. A Coastal Flood Advisory have been extended
through Friday morning, as latest Probabilistic Extra-tropical
Storm Surge (PETSS) guidance indicates that water levels will
peaking at about 1.5 to 2 feet above Mean Higher High Water
(MHHW) during times of high tide through tonight at most tidal
gauges.

Strengthening onshore winds later today and tonight will result in
a significant, long duration tidal flood event beginning with the
late morning high tide cycle on Friday along the Atlantic coast.
Confidence continues to grow for widespread moderate flooding
around times of high tide beginning on Friday, initially along the
Atlantic coast and then spreading to the St. Johns River basin.

We adjusted the Coastal Flood Watch onset to Friday to highlight
the expected higher water levels that guidance is indicating from
Friday through Saturday along the Atlantic coast, with moderate
flooding likely to begin within the St. Johns River basin later on
Friday or Saturday. This event will likely result in the highest
tidal levels that we have seen in our area thus far this Fall, and
a Coastal Flood Warning will likely be issued later today as the
main event draws nearer. Latest PETSS guidance indicates that
water levels should peak in the 2 - 3 foot range above MHHW along
the Atlantic Coast during the high tide cycle around noon on
Friday and during the early afternoon on Saturday`s high tide
cycle, and we still cannot rule out levels in the 3 - 3.5 foot
range, especially over coastal southeast GA, where Major flooding
cannot be ruled out. Moderate flooding appears to be likely within
the St. Johns River basin by Saturday, where water levels will
likely peak in the 2-3 foot range above MHHW during times of high
tide this weekend and possibly extending into Monday.

Strong onshore winds, elevated tide levels, and pounding surf,
featuring breakers of 7-9 feet along the northeast FL beaches,
will bring the potential for destructive beach erosion all along
the Atlantic coast from Friday through the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  76  59  73  60 /  30  40  30  20
SSI  78  66  75  65 /  50  60  70  60
JAX  81  67  76  65 /  60  60  70  50
SGJ  82  70  79  68 /  60  70  80  60
GNV  85  68  79  65 /  30  30  50  30
OCF  85  70  80  68 /  20  20  40  20

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 10 AM EDT Friday for FLZ038-124-125-
     132-137-138-225-233-325-333-633.

     Wind Advisory from 2 PM this afternoon to 5 AM EDT Sunday for
     FLZ038-124-125-138-233-325-333-433-533-633.

     Coastal Flood Watch from Friday morning through late Saturday
     night for FLZ038-124-125-132-137-138-225-233-325-333-633.

     High Rip Current Risk through late Saturday night for FLZ124-125-
     138-233-333.

     High Surf Advisory from 2 PM this afternoon to 6 AM EDT Sunday
     for FLZ124-125-138-233-333.

GA...Coastal Flood Advisory until 10 AM EDT Friday for GAZ154-166.

     Wind Advisory from 2 PM this afternoon to 5 AM EDT Sunday for
     GAZ154-166.

     Coastal Flood Watch from Friday morning through late Saturday
     night for GAZ154-166.

     High Rip Current Risk through late Saturday night for GAZ154-166.

     High Surf Advisory from 2 PM this afternoon to 6 AM EDT Sunday
     for GAZ154-166.

AM...Small Craft Advisory from 8 AM this morning to 2 PM EDT this
     afternoon for AMZ450-452-454-470-472-474.

     Gale Warning from 2 PM this afternoon to 6 AM EDT Sunday for
     AMZ450-452-454-470-472-474.

&&

$$