-- Discussion containing changed information from previous version are highlighted. --
316
FXUS62 KJAX 122344
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
744 PM EDT Sat Jul 12 2025

...New AVIATION...

For the latest NE FL and SE GA Daily Key Messages please visit:
https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

.AVIATION...
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(00Z TAFS)
Issued at 744 PM EDT Sat Jul 12 2025

Light showers near SGJ will dissipate before 01Z. Otherwise, VFR
conditions will prevail at the regional terminals through at least
06Z Sunday. Periods of IFR visibilities are expected overnight at
VQQ. A brief period of MVFR ceilings between 2,000 - 3,000 feet
will be possible at the terminals during the late morning hours on
Sunday, but confidence was too low to include anything other than
scattered ceilings at this time. Showers and thunderstorms will
develop after 17Z along the Atlantic sea breeze boundary near the
SGJ and SSI coastal terminals, with activity then expected to
shift inland after 19Z, with coverage and intensity of convection
expected to increase during the mid to late afternoon hours.
Thunderstorms should shift west of the I-95 corridor by 23Z, with
activity potentially lingering into the early evening hours at VQQ
and GNV. PROB30 groups were included at each terminal on Sunday
afternoon for brief wind gusts up to 30 knots and IFR
visibilities during heavier downpours. Southerly surface winds
sustained at 5-10 knots early this evening will shift to
southwesterly by midnight, with speeds remaining around 5 knots at
the coastal terminals overnight. Surface winds will then shift to
west-northwesterly shortly after sunrise, with speeds increasing
to 5-10 knots by 14Z. The inland moving Atlantic sea breeze
boundary will shift winds to east-southeasterly after 17Z at SGJ,
with speeds increasing to 10-15 knots, while southerly winds of
10-15 knots are forecast at SSI after 18Z.
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&&

.NEAR TERM...
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(Rest of Today through Tonight)
Issued at 205 PM EDT Sat Jul 12 2025

Mid level ridge is located from the central Gulf coast
southeastward to south FL, with broad troughing across SC/NC
southward into the far western Atlantic. The troughing offshore
will dig through tonight, while the mid level ridge will
retrograde slightly. This will result in mean layer winds to veer
a bit through tonight. At the sfc, weak high pres ridge over south
central FL will shift southward, while weak troughing will
develop further offshore of the southeast U.S. coast, more or less
tied to a weak 1015 mb low pressure system developing along the
SC/NC state line.

Locally, for the rest of the afternoon, generally expect
scattered showers and storms that will be moving slightly faster
than yesterday, to the east or east-southeast. Expect that a few
of these storms will move into the area coastal waters as well.
Overall, convective parameters are not too far off from normal
with MLCAPE and DCAPE of near 2700 J/kg and 800-1000 J/kg,
respectively. We can`t rule a severe storm with a downburst winds
to 50, possibly 60 mph, given the relatively favorable environment
(compared to yesterday). Thete-E differences are in the
neighborhood of 25-30.

While most of the deep convection will diminish and tend to
dissipate in the evening, the fact that we have some energy
rotating around the mid level ridge late tonight across parts of
the forecast area late tonight, isolated convection is likely late
tonight. This convection will probably be on the weak side.
Indeed, almost all the model guidance has some precip falling
after midnight mainly central and eastern parts of the area.
Again, this activity, should move toward the southeast as the mean
flow veers into Sunday morning.

Temps: in the lower to mid 90s rest of the aftn, and latest heat
indices generally range from 101-106, with a few higher values out
there but are suspect observations. Some of the precip occurring
now may bring down indices a few values in some locations. Lows
tonight in the mid 70s mostly.
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&&

.SHORT TERM...
(Sunday through Monday night)
Issued at 205 PM EDT Sat Jul 12 2025

Rather weak troughing/broad low pressure starts to shift south
and southwestward from the Carolinas on Sunday, slowly moving
towards and over the Florida Peninsula through Monday and Monday
Night. This will have several implications, firstly breaking down
high pressure ridging that has kept us in a mostly west to
southwest flow, and secondly increasing rain/t`storm coverage
across most of the area. The low will induce more of a northwesterly
flow on Sunday, which will try to bring in some drier air into
southeast GA and therefore tempering PoPs and convective coverage
a bit in those areas, however. The more north to northwesterly
flow near the surface and aloft will also result in a rather rare
summer north to south storm motion Sunday. Highest convective
coverage as well as the greatest threat for any strong to isolated
severe storms will therefore be across northeast FL, and
especially south of I-10 and towards the FL coast where the best
convergence will be. Gusts up to 40-60 mph and minor flooding from
heavy rainfall will be the primary hazards. Highs will remain
quite warm with offshore flow, as mid 90s will be common. The
highest readings likely to be across inland GA with less
convective coverage and some drier air where upper 90s will be in
store for some. As low pressure continues to push southward Sunday
Night, this will likely keep some showers and t`storms going
throughout the night over area waters and especially offshore
waters, as well as over parts of northeast FL. Low temps will be
mild Sunday Night, in the mid to upper 70s.

Monday, broad low pressure will be located almost directly over
north FL before slowly drifting southwestward towards the
northeast Gulf Monday Night. The presence of the low and some weak
energy aloft will maintain active convection, including increased
coverage likely into southeast GA as well. The position of the low
will shift flow towards the north to northeast throughout the day,
with the east coast sea breeze therefore progressing far inland
and likely shifting the "corridor" of highest PoPs and stronger
t`storm chances inland and towards the nearly pinned west coast
sea breeze during the afternoon and evening. More of a continental
wind direction will hold strong enough inland for mid to upper 90s
to continue Monday. However, temps from about the I-95 corridor
and to the coast will nudge down a bit closer to the lower 90s
where there will be more of a sea breeze influence.

&&

.LONG TERM...
(Tuesday through next Saturday)
Issued at 205 PM EDT Sat Jul 12 2025

The broad and weak low will drift southwestward into the Gulf Tuesday
and into Wednesday as high pressure starts to rebuild from the
east to northeast through the end of the week. The National
Hurricane Center (NHC) has placed a 20% chance of tropical or
subtropical development somewhere over the north/northeast Gulf
during the longer term, though impacts, if any, do not look
significant and likely west of our area at this time. We will of
course continue to keep a close eye on trends and forecasts
accordingly. Otherwise, the long term looks to mostly consist of
near to above average shower/t`storm chances and an onshore flow
regime. Temperatures overall will trend near normal, though start
to nudge upward towards late week as flow becomes more southeast
as compared to east/northeast.

&&

.MARINE...
Issued at 205 PM EDT Sat Jul 12 2025

High pressure extending across central Florida will move south
through Monday while a surface trough develops over portions of the
area coastal waters. The surface trough will move west of the area
by early Tuesday. Scattered thunderstorms will be possible each day
over area waters. Some storms may produce strong gusty winds and
frequent lightning. Winds of 10-15 kt or less and seas of 3 ft or
less anticipated into Sunday and probably Monday. Some slight
uptick in in the winds and seas are likely by Tuesday and
Wednesday, with the wind flow becoming more east and southeast.

Rip Currents: Low to moderate risk of rip currents continues with
surf/breakers around 2 feet, with a slight subsiding trend to 1-2
feet by Sunday/Monday, with low to moderate risk of rip currents
continuing.

&&

.PRELIMINARY POINT TEMPS/POPS...
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AMG  74  98  75  96 /  10  30  30  50
SSI  77  94  78  92 /  20  40  20  40
JAX  76  97  75  95 /  30  60  40  70
SGJ  77  93  76  92 /  40  70  20  70
GNV  76  94  74  96 /  30  70  20  90
OCF  75  93  75  94 /  20  80  40  90
-- End Changed Discussion --

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&

$$