532
FXUS62 KJAX 242341
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
741 PM EDT Sun Aug 24 2025

...New AVIATION...

.SYNOPSIS...
Issued at 302 PM EDT Sun Aug 24 2025

Late morning surface analysis depicts developing low pressure
(1007 millibars) situated near Cape Hatteras along a frontal
boundary that extends off the southeastern seaboard and along the
Interstate 10 corridor. Meanwhile, a cold front was pushing
southeastward across the eastern Great Lakes and the
Ohio/Tennessee Valleys and the Ozarks, with strong high pressure
(1029 millibars) building over the Northern Plains states in the
wake of this cold front. Aloft...a potent shortwave trough
traversing the Great Lakes region was carving out a longwave
trough over the eastern half of the nation. Deep southwesterly
flow prevails at the base of this trough across our region above
700 millibars (around 10,500 feet) per the morning sounding at
Jacksonville, with shortwave impulses embedded within this
southwesterly flow triggering widespread convection across the
northern and eastern portions of the Gulf, with this activity
extending across the FL peninsula, mostly from the I-4 corridor
southward. Latest GOES-East derived Total Precipitable Water
imagery indicates that a drier air mass was beginning to advect
southeastward into interior southeast GA and the Suwannee Valley,
where PWATs were falling below 1.7 inches. Deep tropical moisture
otherwise prevails over our area, with PWAT values around 2 inches
for locations along and north of I-10, while values were around or
in excess of 2.25 inches for coastal southeast GA and the rest of
northeast and north central FL. Temperatures were generally in the
85 to 90 degree range as of 19Z, with dewpoints mostly in the
70s, except upper 60s for locations northwest of Alma in interior
southeast GA.

&&

.NEAR TERM...
(through Tonight)
Issued at 302 PM EDT Sun Aug 24 2025

Showers were increasing in coverage along and ahead of a frontal
boundary for locations along and south of the Interstate 10
corridor this afternoon, with this activity pushing
southeastward along and ahead of the aforementioned frontal
boundary. We expect thunderstorms to develop within this activity
as it continues to gradually increase in coverage and intensity
this afternoon for locations south of I-10. Meanwhile, convective
outflows pushing northward from current activity in central FL
will collide with mesoscale boundaries and convection along the
frontal boundary late this afternoon, with storms potentially
pulsing and moving slowly over southern portions of the St. Johns
River basin as well as north central FL. Localized flooding and a
few strong storms will be possible, especially over eastern
Marion, Putnam, Flagler, and St. Johns Counties, where widespread
rainfall amounts of around 1 inch with localized totals of 2-4
inches will present a localized flood threat, especially for
normally flood prone, urban locations such as Palatka during the
late afternoon and early evening hours. Meanwhile, the drier air
mass spilling into southeast GA this afternoon should limit
coverage of showers and thunderstorms later today to isolated to
widely scattered at best.

Convection may linger across north central FL and southern
portions of the Suwannee Valley this evening as southwesterly flow
aloft and shortwave energy continues to develop widespread
convection across the eastern Gulf overnight. Widely scattered
convection may push onshore from the FL Nature Coast and Big Bend
into western and central portions of Marion County and possibly
southern portions of the Suwannee Valley overnight as the frontal
boundary pushes across north central FL. Mid and high altitude
cloud cover emanating from this activity may shroud our skies
overnight, keeping lows around 70 for inland southeast GA and the
low to mid 70s elsewhere.

&&

.SHORT TERM...
(Monday through Tuesday night)
Issued at 302 PM EDT Sun Aug 24 2025

A slow moving cold front will be located across the southeastern US
on Monday. This boundary will cross into inland SE GA counties in
the afternoon, bringing drier airmass with it. South of the front,
the airmass will continue to be moist. Convection chances, for all
but far inland SE GA, due to diurnal heating, sea breeze
interactions, and focus along front. The greatest chances will be
across NE FL south of I10. The flow will be fairly light, so storms
will be slow moving and capable of producing heavy rainfall. Highs
Monday will trend a little above seasonal averages.

The front will sink to near the GA/FL line Monday night. North of
this boundary a dry night is forecast, but a few showers could
linger along and south of it. Lows will be near to a little above
normal across NE FL, and coastal SE GA, but below for inland SE GA.

On Tuesday, the weakening frontal boundary is expected to stretch
across Northern FL. Due to the position of the front, and the drier
airmass advecting in north of it, much of SE GA will be dry Tuesday.
Convective chances will exist across NE FL, with the highest chance
south of Gainesville. Highs Tuesday will be near to above average.
For locations across SE GA and inland NE FL the airmass will have
noticeably lower humidity.

The front, which will be nearly dissipated by Tuesday night, will be
slide to the south of the area overnight. The lower dewpoint airmass
will settle across much of the area during the overnight, allowing
temperatures to fall below average. For areas closer to the coast,
the proximity of the ocean will keep the air more moist and
milder.

&&

.LONG TERM...
(Wednesday through next Sunday)
Issued at 302 PM EDT Sun Aug 24 2025

High pressure will build from the northwest and north Wednesday.
While the airmass will remain dry inland, a light flow across the
coastal waters will push the east coast sea breeze inland through
the day. This will bring in enough moisture for convection across
NE FL, and eastern SE GA during the heat of the day. Highs will be
near seasonal levels, but again the humidity levels will be
noticeably lower across inland areas.

High pressure centered to the north on Thursday, will gradually
build more toward the northeast through the weekend. As the pattern
changes the flow will become increasingly onshore, causing moisture
to increase across area. The exception will be across far inland
SE GA, where a drier over land flow will persist. Daily
precipitation chances will increase from south to north through the
end of this period. Daytime temperatures will trend below normal
later in the week through the weekend. Lows will be below normal
inland, but near to above near the coast.

&&

.AVIATION...
(00Z TAFS)
Issued at 731 PM EDT Sun Aug 24 2025

Some SHRA will linger near Duval County airfields over the next
few hours, which could drop vsbys towards MVFR briefly at times.
FG and low stratus are expected to impact inland terminals once
again early Monday Morning, with IFR and LIFR expected at times.
Some of these lower vsbys/ceilings could make it towards JAX and
CRG, though confidence is not high enough to include in the
forecast at this time. Most SHRA and TSRA are expected to be
confined to northeast FL on Monday afternoon and evening as some
dry air filters in from the northwest. Confidence in TSRA impacts
only high enough to include PROB30 groups at SGJ and GNV at this
time, though there is a small chance for Duval terminals as well.

&&

.MARINE...
Issued at 302 PM EDT Sun Aug 24 2025

Long period swells will continue to impact our local waters,
keeping combined seas elevated through tonight. Areas near inlets
may be choppy from this swell activity today. Seas of 3-5 feet
will prevail offshore through Tuesday, while seas near shore will
remain in the 2-4 foot range. Meanwhile, a slow moving cold front
positioned across Interstate 10 will slowly drift southward
through tonight. Showers and thunderstorms will impact our local
waters this afternoon through early evening. The frontal boundary
will then push south of our local waters on Monday evening,
stalling across the Florida peninsula by midweek, resulting in a
decreasing coverage of showers and thunderstorms for our area on
Tuesday and Wednesday. Breezy northeasterly winds will may then
develop by Wednesday and Thursday as high pressure builds over the
Ohio Valley and coastal troughing develops across the northeast
Florida waters, where chances for showers and thunderstorms will
increase later this week.

Rip Currents: Long period swells of 3-5 feet with swell periods of
13-15 seconds will continue today. Breakers of 2-4 feet at the
northeast FL beaches will keep a high risk of rip currents in
place today, while breakers of around 2 feet at the southeast GA
beaches keep a higher end moderate risk in place. Lengthy swell
periods will likely keep an elevated rip current risk in place on
Monday and Tuesday at area beaches.

&&

.FIRE WEATHER...
Issued at 1145 AM EDT Sun Aug 24 2025

Light northwesterly surface and transport winds today for
locations along and north of Interstate 10 will yield low daytime
dispersion values. West-southwesterly transport winds will become
breezy this afternoon across north central FL, where fair daytime
dispersion values are forecast. Poor values are expected elsewhere
today. West-northwesterly surface and transport winds are forecast
for locations along and north of I-10 on Monday, with breezy
southwesterly transport winds continuing across north central FL.
Elevated mixing heights on Monday will create good daytime
dispersion values at inland locations, with fair values forecast
at coastal locations. Surface and transport winds will then become
northwesterly area-wide by Tuesday morning, with northeasterly
surface winds developing at coastal locations during the
afternoon hours, where fair values are forecast. Elevated mixing
heights will again yield mostly good daytime dispersion values at
most inland locations on Tuesday afternoon.

&&

.HYDROLOGY...
Issued at 1145 AM EDT Sun Aug 24 2025

Slow moving downpours and embedded thunderstorms are expected to
develop during the mid to late afternoon hours, mainly for
locations south of the Interstate 10 corridor. The Weather
Prediction Center has included these areas within a "Marginal"
Risk (level 1 of 4) for Excessive Rainfall later today and this
evening. Widespread rainfall totals of around 1 inch, with
localized totals of 2-4 inches will be possible, with short-term,
high resolution guidance indicating that areas most at risk for
flooding downpours will be across southern portions of the St.
Johns River basin, mainly for Putnam, St. Johns, and Flagler
Counties.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  71  91  65  90 /  20  10   0   0
SSI  74  90  72  90 /  20  30  10  10
JAX  73  92  72  93 /  30  50  10  20
SGJ  74  91  74  91 /  50  50  20  40
GNV  73  91  73  93 /  40  60  10  40
OCF  73  90  74  91 /  40  70  10  60

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until 6 AM EDT Monday for FLZ124-125-138-
     233-333.

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

$$