534
FXUS62 KJAX 190628
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
228 AM EDT Tue Aug 19 2025

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

...HAZARDOUS SURF ZONE CONDITIONS TODAY THROUGH THURSDAY...

.NEAR TERM...
Issued at 156 AM EDT Tue Aug 19 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

Warmer, breezier with less rainfall coverage today compared to
past days as subsidence on the west side of Hurricane Erin
strengthens across the local area. Surface high pressure building
across New England extends a ridge axis southward down across
northern GA today as Hurricane Erin continues to track NNW, east
of the Bahamas. The resultant pressure gradient between these two
systems increases local NE winds through the day, with gusts
nearing 25 mph this afternoon at the coast and near the St Johns
River. A couple of convergent bands of showers were noted early
this morning offshore of the Atlantic coast, with a chance
(20-30%) of morning showers, including waterspout potential across
the Atlantic waters. Through the day, a more dominant east coast
sea breeze develops with scattered showers and storms popping
along the inland progressing sea breeze into the afternoon. Drier
mid level air will limit precipitation coverage, especially across
SE GA through the day, but a low 20-30% chance of late afternoon
and evening showers/storms was continued for locations generally
north of Waycross with a passing low level trough axis. The main
storm hazards will be locally gusty wet downbursts with drier air
and faster NE to SW storm motion limiting flooding rain risk
compared to recent days. The main impacts from Hurricane Erin will
continue to focus along the local coast and over the adjacent
marine waters - please refer to the Marine and Hydrology sections
below for more details.

Temperatures will trend near to above normal today and tonight
with highs in the low to mid 90s inland to near 90 coast and peak
heat index values 100-105 degF. Tonight, lows will range in the
70s inland to near 80 toward the coast under breezy onshore flow.

&&

.SHORT TERM...
(Wednesday through Thursday night)
Issued at 156 AM EDT Tue Aug 19 2025

Ridging across the southeastern US combined with Hurricane Erin
passing several hundred miles east of the Florida Peninsula will
result in a breezier and mainly dry day on Wednesday, as the
subsident flow west of the system drops PWATs below average in the
1.5-1.8 inch range. With the subsidence and flow regime, looking
at mainly just coastal showers and perhaps an isolated t`storm
Wednesday given the shallow ocean moisture, though still cannot
rule out an isolated shower or t`storm inland during peak diurnal
heating - though it is quite possible that the western half of the
CWA does not see any rain at all Wednesday and Wednesday Night.
Temperatures Wednesday range from around 90 near the immediate
coast to the low to mid 90s the further inland you go. Mostly
clear Wednesday Night with lows mainly in the mid to upper 70s.

Slightly below normal PWATs linger into Thursday as Erin pulls
away, though PWATs "rebound" slightly to around 1.7-1.9 inches and
therefore slightly higher rain chances will be expected,
especially over northeast FL where better lower level moisture
will be. Flow will subside a bit while also backing towards the
northwest at around the 5-10 mph range on Thursday, allowing more
of a sea breeze influence and therefore more of a catalyst to fire
some convection during the afternoon and evening. Temps will
mostly be a touch warmer on Thursday with the shift in the flow,
as mid 90s will be most common except at the coast where low 90s
will be expected. A few showers or isolated t`storms may linger
into the overnight hours Thursday with any remaining boundary
collisions as well as the pseudo frontal boundary from departing
Erin dropping towards southeast GA. Min temps in the mid to upper
70s will be expected once again Thursday Night.

&&

.LONG TERM...
(Friday through Monday)
Issued at 156 AM EDT Tue Aug 19 2025

High pressure will build in from the northeast Friday into
Saturday and linger through the weekend, with higher layer
moisture also returning. Scattered to numerous diurnally driven
showers and thunderstorms are expected to return accordingly both
afternoons, with flow weak enough for a sea breeze influence to
help strengthen storms. Our office as well as the National
Hurricane Center is monitoring the potential for another tropical
wave to approach the Bahamas around the Sunday/Monday time frame,
though forecast confidence is low at this time and therefore it is
too early to determine potential impacts, if any. Continue to
monitor NHC forecasts over the coming days and maintain tropical
readiness as we approach peak Hurricane Season! Temperatures trend
mainly above normal for the long term.

&&

.AVIATION...
(06Z TAFS)
Issued at 133 AM EDT Tue Aug 19 2025

Prevailing VFR conditions with restrictions through 12z possible
at VQQ due to shallow ground fog and brief MVFR due to passing
coastal showers at SSI and SGJ. Indicated TEMPO IFR at VQQ for
now and will monitor radar trends for TEMPOs at coastal terminals.
Continued with PROB30s for TSRA today given lower potential as
drier air begins to infiltrate across the area on the subsident
side of Hurricane Erin. Breezy NE winds today with coastal gusts
up to 20-25 kts at times into the afternoon and evening. Winds
remain elevated at the coast tonight after 00z with passing low
clouds and potential showers but chances too low to include in
TAFs at this time.

&&

.MARINE...
Issued at 156 AM EDT Tue Aug 19 2025

High pressure across New England extends south across north
Georgia today as Hurricane Erin tracks northwest to north,
remaining east of the Bahamas. This pattern will bring
strengthening northeast winds over the local waters today as
swells continue to build. Erin tracks north tonight and then
northeast into late Wednesday remaining offshore of the North
Carolina coast. An extended period of Small Craft conditions will
impact the local waters through Saturday due to lingering swells.
A front will stall across the region Friday into the weekend
bringing an increase in shower and thunderstorm activity.

Rip Currents: High rip current risk for all local beaches through
at least Thursday due to long period swells from Erin. High risk
may need to be extended into Saturday.

Surf: High surf advisory in effect through Thursday for breaker
heights > 7 ft at local beaches today, building to 5-8 ft into the
evening, then breaker heights peaking Wednesday evening into the
7-11 ft range. Given the northerly wind fetch, the more vulnerable
beaches will be from Duval county southward to Flagler county for
beach erosion. Breaker heights subside into the 5-8 ft range
Thursday with minor beach erosion will be possible during the
early evening high tide Thursday.

&&

.HYDROLOGY...
Issued at 156 AM EDT Tue Aug 19 2025

River flooding...The Altamaha River at Baxley fell below Minor
flood stage overnight.

Coastal & Tidal Flood Risk: Deterministic forecast guidance continued
to indicated minor tidal flooding inundation around high tide Wednesday
evening along the local Atlantic coast which is about 1.8 to 2 ft
MHHW/AGL datum. There is less than a 10% chance of moderate tidal
flooding impacts - which is generally around 2.5 ft MHHW/AGL datum
for coastal locations. For the St. Johns River basin, locations
south of the Buckman Bridge toward Satsuma will be more vulnerable
to Minor tidal flooding impacts Wednesday night high tide cycle
given the northerly wind fetch. At this time, the above forecast
values would still support a Coastal Flood Advisory to possibly be
issued later today or tonight for coastal locations Wednesday and
Thursday for minor, nuisance flooding in normally tidal flood
prone areas. As a reminder, you can monitor water levels and see
what water level impacts occur at specific locations by clicking
on a location of interest at water.noaa.gov

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  93  72  93  73 /  20  10  10   0
SSI  89  76  91  77 /  20  20  30  10
JAX  91  75  94  75 /  30  10  30  10
SGJ  89  78  90  76 /  40  20  40  10
GNV  93  74  94  75 /  50  10  20  10
OCF  92  74  93  75 /  50  10  20  10

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through late Thursday night for FLZ124-125-
     138-233-333.

     High Surf Advisory from noon today to 2 AM EDT Friday for FLZ124-
     125-138-233-333.

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

     High Surf Advisory from noon today to 2 AM EDT Friday for GAZ154-
     166.

AM...Small Craft Advisory until 4 AM EDT Friday for AMZ450-452-454.

     Small Craft Advisory until 8 AM EDT Saturday for AMZ470-472-474.

&&

$$