Spring Bluff, Georgia Weather Forecast Discussion

006
FXUS62 KJAX 241831
AFDJAX
Area Forecast Discussion
National Weather Service Jacksonville FL
231 PM EDT Wed Sep 24 2025
...New SYNOPSIS, NEAR TERM, SHORT TERM, LONG TERM, AVIATION, MARINE...
.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
- Near Record Highs & Heat Indices 95 - 105 F through Friday
- Isolated Strong Storms Thursday Evening for Inland Southeast GA
- Two Tropical Waves with Development Potential - Monitor the
  Latest Updates at hurricanes.gov
- Marine & Surf Zone Hazard Potential Early Next Week
&&
.SYNOPSIS...
Issued at 228 PM EDT Wed Sep 24 2025
Afternoon surface analysis depicts high pressure (1020 millibars)
centered over north central FL. Meanwhile, a wavy frontal
boundary extends from coastal New England and the Mid-Atlantic
states southwestward across the Ohio Valley and through the
Ozarks and the Texas Hill Country. Aloft...ridging extending
across the FL peninsula and the Bahamas was flattening in response
to a trough positioned over the Great Lakes region that was
poised to gradually dig southeastward. Meanwhile, a potent
shortwave trough was progressing from the southern Plains states
towards the Ozarks, with this feature triggering convection
across eastern Texas and the lower Mississippi Valley. Latest
GOES-East derived Total Precipitable Water imagery indicates that
moisture levels across our region remain near or slightly below
late September climatology, with values ranging from around 1.4 to
1.8 inches. Isolated showers were developing along the inland
moving Atlantic and Gulf coast sea breezes, as well as along other
mesoscale boundaries such as the St. Johns River breeze and the
Lake George breeze. A healthy cumulus field otherwise prevails
across our region as of 18Z, with temperatures in the upper 80s
and lower 90s inland and the mid to upper 80s at coastal
locations. Dewpoints ranged from the mid and upper 60s across
inland southeast GA and the Suwannee Valley to the mid 70s at
coastal locations, creating Heat Index values around 100 degrees
at most locations.
&&
.NEAR TERM...
(through Tonight)
Issued at 228 PM EDT Wed Sep 24 2025
Weakening high pressure will push slowly southward tonight, with
a loose local pressure gradient allowing both the Atlantic and
Gulf coast sea breezes to progress steadily inland this afternoon
and evening, setting up a collision near the U.S. Highway 301
corridor towards sunset. Additional mesoscale boundary collisions
and the hot, humid air mass should develop widely scattered
convection late this afternoon and early this evening, mainly for
locations west of the I-95 corridor across inland northeast and
north central FL. Meanwhile, PWATs this afternoon will likely
remain below 1.5 inches across inland portions of southeast GA,
likely negating rain chances for all but perhaps the Okefenokee
Swamp during the evening hours.
Isolated convection may linger along or just east of the U.S.-301
corridor in northeast and north central FL through around
midnight tonight, perhaps extending northward across the
Okefenokee Swamp. Debris cloud cover from any convection that
manages to develop should thin out overnight, with low level
southwesterly flow likely advecting fog and low stratus clouds
from Apalachee Bay northeastward across the Suwannee Valley and
the I-75 corridor, with this fog and low stratus clouds pushing
towards the U.S.-301 corridor in northeast and north central FL
towards sunrise on Friday. Lows tonight will generally range from
around 70 across inland southeast GA and the Suwannee Valley to
the mid 70s at coastal locations.
&&
.SHORT TERM...
(Thursday and Friday)
Issued at 228 PM EDT Wed Sep 24 2025
High pressure ridge across the area will start to break down and
shift northeastward away from the area on Thursday as a cold front
and upper trough approaches from the northwest. This will shift
the low level flow to be southwestward Thursday and Friday,
bringing in enough moisture for decent thunderstorm potential both
days. Thursday, there is a Marginal risk of severe storms over
inland southeast Georgia as moderate instability develops ahead of
the approaching front with dewpoints forecast to be in the lower
70s. The primary hazard Thursday will be strong to isolated severe
wind gusts/downbursts as PWATs approach 2 inches and lapse rates
remain fairly weak. As of now, it appears the strong to severe
storms will approach in the evening, so timing of this will be
critical for determining impacts. If it comes closer to sunset
there will not be much time for favorable conditions to keep
storms intense, although convection lingering through the first
half of the night is possible. Temperatures Thursday remain above
normal, with highs in the lower 90s inland and upper 80s to low
90s along the immediate coast.
Storm chances increase further on Friday as the front slowly sinks
into southeast Georgia, aiding convection near there in the
afternoon and evening. Aside from the front, southwest flow will
spark up storms across northeast Florida as sea breezes interact
closer to the east coast. The front will help keep temperatures a
bit cooler over inland southeast Georgia on Friday, highs will
stay in the mid 80s, with upper 80s to low 90s elsewhere.
&&
.LONG TERM...
(Saturday through Tuesday)
Issued at 228 PM EDT Wed Sep 24 2025
The biggest story for the long term forecast is the certainty of
the aforementioned front reaching the southeastern United States,
and the uncertainty among long range models on the potential
track/intensity of Invest 94L and progression of the front. For
example, the GFS favors a solution where the front pushes through
faster, keeping Invest 94L fairly weak and staying offshore while
Invest 93L just to it`s east dominates the western Atlantic. The
ECMWF shows slower frontal progression, allowing I-94L to develop
near the Bahamas and have some time to strengthen while
approaching the US coast as the front stalls just off the
Georgia/Carolinas coast early next week, later pushing away from
the coast. The uncertainty in model solutions for the frontal
system and potential tropical systems creates a difficult forecast
for the long term, and whether or not these two systems interact
makes the forecast even more challenging. The National Hurricane
Center gives Invest 94L a 90% chance of formation in the next 7
days, likely to form near the Bahamas and move northwestward.
Please continue to monitor the tropical outlook at hurricanes.gov
and prepare for potential marine, coastal, and surf zone impacts.
Outside of talking about the tropics, locally we expect below
normal temperatures and higher rain chances on Saturday as the
front moves through the area. Sunday onward, temperatures will
just at or above normal this weekend into early next week with
scattered rain and storm chances primarily near the Atlantic coast
as northeasterly winds strengthen.
&&
.AVIATION...
(18Z TAFS)
Issued at 150 PM EDT Wed Sep 24 2025
Isolated convection is expected to develop near JAX, VQQ, SGJ, and
GNV late this afternoon through the early evening hours.
Confidence in impacts at JAX and SGJ remains too low for anything
other than a vicinity shower mention through sunset. We maintained
PROB30 groups for MVFR conditions during heavier downpours after
21Z at VQQ and GNV, with activity expected to dissipate towards
03Z. Periods of IFR conditions will be possible after 07Z at VQQ,
while MVFR visibilities will be possible after 09Z at GNV.
Visibilities may also lower at JAX towards sunrise on Thursday,
but confidence was too low to indicate any restrictions near the
end of this TAF period at this time. VFR conditions will then
prevail by 14Z Thursday at the regional terminals. Onshore surface
winds will prevail at CRG and the SGJ and SSI terminals through
around 01Z, followed by winds shifting to southerly and remaining
sustained around 5 knots overnight. Southwesterly surface winds of
5-10 knots will prevail at GNV through around 02Z, with
diminishing speeds expected overnight. Light west or northwesterly
surface winds sustained around 5 knots elsewhere will shift to
southeasterly around 10 knots before 22Z. West-southwesterly
surface winds are expected to develop towards 13Z Friday, with
speeds increasing to 5-10 knots by 16. The Atlantic sea breeze
boundary will then cross the coastal terminals by 17Z Friday,
resulting in onshore surface winds increasing to around 10 knots
towards 18Z.
&&
.MARINE...
Issued at 228 PM EDT Wed Sep 24 2025
High pressure currently positioned over our region will sink
southward later tonight ahead of a frontal boundary that will be
entering the southeastern states. Showers and thunderstorms will
increase in coverage as this front approaches our area from the
west on Friday and Saturday. Seas of 2-4 feet will prevail
throughout our local waters through Saturday night. This front
will then stall over our local waters on Sunday as a tropical wave
currently moving eastward across Puerto Rico potentially develops
into a tropical cyclone near the Bahamas during the weekend. This
developing low pressure center will likely shift north or north-
northwestward early next week, potentially approaching the
southeastern seaboard, resulting in strengthening northeasterly
winds and building seas across our local waters beginning on
Sunday and continuing through the early portions of next week.
Rip Currents: A high rip current risk continues for St. Johns and
Flagler county beaches this afternoon due to a long period east-
southeasterly ocean swell combining with the afternoon sea breeze.
A higher end moderate rip current risk is expected elsewhere
this afternoon, with this higher end moderate risk expected for
all local beaches on Thursday.
&&
.FIRE WEATHER...
Issued at 1145 AM EDT Wed Sep 24 2025
Light southwesterly transport winds will prevail this afternoon,
with breezy onshore surface winds developing at coastal locations
this afternoon, where poor daytime dispersion values are forecast.
Elevated mixing heights will yield good daytime dispersion values
for locations west of Waycross and Lake City, while fair values
prevail elsewhere inland. Southwesterly transport winds will
strengthen on Thursday, with breezy conditions north of I-10
during the afternoon hours creating marginally high daytime
dispersion values, while good values prevail elsewhere inland.
Fair daytime dispersion values are forecast at coastal locations,
where breezy onshore surface winds will again develop during the
afternoon hours. Southwesterly transport winds will then weaken on
Friday, with elevated mixing heights yielding good daytime
dispersion values for locations along and east of U.S. Highway
301, while fair values are forecast elsewhere.
&&
.CLIMATE...
Issued at 210 AM EDT Tue Sep 23 2025
The past 2 days Gainesville was within 1 degree of a daily record
high temperature: 9/23 96 (record 97 set in 1925) and 9/22 96 (96
set in 1925).
Craig Airfield reached 90 yesterday (9/23) which was 1 degree
shy of the daily record high of 91 (set in 2016).
Daily record highs and daily record high minimum temperatures for
the next couple of days are below:
DATE      9/24     9/25    Normals
JAX      94/2019  96/2019  High: 86
         78/1951  76/1930  Low: 69
CRG      93/2019  95/2019  High: 85
         77/2017  76/1998  Low: 71
GNV      95/1997  96/1931  High: 87
         75/1998  74/2010  Low: 68
AMG      95/2019  98/1961  High: 86
         74/2000  74/1988  Low: 65
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG  69  93  69  86 /   0  20  30  70
SSI  74  89  73  87 /   0  10  20  50
JAX  72  92  72  91 /  10  20  10  70
SGJ  73  91  73  90 /  10  20  20  60
GNV  71  93  70  92 /  30  30  10  60
OCF  72  91  72  90 /  20  30  10  50
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until 8 PM EDT this evening for FLZ138-233-
     333.
GA...None.
AM...None.
&&
$$

NWS JAX Office Area Forecast Discussion