185
FXUS62 KJAX 240729
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
329 AM EDT Tue Jun 24 2025

...TEMPERATURES SOAR TO THE UPPER 90S INLAND THIS AFTERNOON...
...STRONG TO ISOLATED SEVERE STORMS POSSIBLE ON WEDNESDAY...
...SEASONABLY HOT WITH AFTERNOON & EVENING STORMS LATE THIS WEEK
THROUGH THE UPCOMING WEEKEND...

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

.SYNOPSIS...
Issued at 329 AM EDT Tue Jun 24 2025

Overnight surface analysis depicts high pressure (1023 millibars)
centered over the Gulf Stream waters offshore of coastal Georgia.
Meanwhile, a wavy stationary frontal boundary extends from the
western Great Lakes southwestward through the southern Plains
states to the Four Corners region. Aloft..."Heat Wave" ridging
was centered over the Mid-Atlantic states and the southern
Appalachians, with this expansive feature controlling the weather
pattern over the eastern half of the nation. Otherwise, a Tropical
Upper Tropospheric Trough (TUTT) was taking shape to the south of
Bermuda, while a slow moving trough was positioned over California
and the Desert Southwest. Latest GOES-East derived Total
Precipitable Water imagery indicates that an unseasonably dry air
mass persists across our region, with PWATs only in the 1.25 - 1.5
inch range, which is only 10%-25% of normal late June climatology
(average values should be near 1.75 inches). Fair skies prevail
area-wide, with temperatures and dewpoints mostly in the 70-75
degree range inland, while a light southwesterly breeze was
keeping coastal temperatures in the upper 70s to around 80 at 07Z.

&&

.NEAR TERM...
(Today and Tonight)
Issued at 329 AM EDT Tue Jun 24 2025

An unseasonably dry and subsident air mass will create a rare,
rain-free late June day throughout our entire area. Surface
ridging along the southeastern seaboard will begin to weaken and
shift southward towards our area this afternoon and evening. The
strongly subsident air mass may result in patchy fog formation
towards sunrise, mainly along the I-95 and U.S. Highway 17
corridors. Any fog that manages to develop will dissipate by an
hour or so after sunrise, with plenty of sunshine and the
persistently dry air mass boosting highs to the mid and upper 90s
inland, with a few locations in the northern Suwannee Valley and
inland southeast GA approaching 100 degrees this afternoon.
Dewpoints will mix down to the upper 60s to around 70 at inland
locations today, which should keep maximum heat index values just
below Heat Advisory criteria (which is 108 degrees). A light
onshore breeze will keep coastal highs closer to 90, where heat
index values will generally reach the 100-105 degree range early
this afternoon.

The TUTT feature spinning over the southwestern Atlantic will get
steered southwestward towards the Gulf Stream waters off FL`s
east coast tonight. Cooling temperatures aloft associated with
this trough may ignite convection towards sunrise over our
offshore Atlantic waters. Otherwise, a gradual increase in high
altitude cloudiness is expected locally, with another round of
patchy fog possible for locations along and east of the U.S.
Highway 301 corridor towards sunrise. Lows will generally fall to
the 70-75 range inland, with mid to upper 70s forecast at coastal
locations.

&&

.SHORT TERM...
(Wednesday through Thursday night)
Issued at 329 AM EDT Tue Jun 24 2025

High pressure to the north begins to weaken and shift southward,
gradually shifting the steering flow from easterly on Wednesday to
more southerly on Thursday. A closed upper low off the eastern
coast of FL will trek WSW along the southern periphery of the
ridge and shift over the FL peninsula Wednesday night into
Thursday. This low will bring an increase in tropical moisture and
a more unsettled pattern aloft, leading to isolated/scattered
showers and storms developing along the sea breezes on Wednesday.
A few strong to severe storms will be possible Wednesday afternoon
into night as cooler temperatures advect in aloft and a potential
stronger upper jet streak moves into the area Wednesday night.
Best chances for stronger storms will be mainly along the sea
breeze merger along and west of I-75 with gusty winds and hail as
the main hazards. Showers and storms will linger over the western
half of our area into the night on Wednesday. With the upper low
overhead and the increase in moisture, storm coverage increases on
Thursday to scattered/numerous. With the shifting flow, the sea
breeze merger will be between I-75 and HWY 301 Thursday afternoon
into evening. With the onshore flow, highs on Wednesday will range
from the upper 80s along the coast to the mid-upper 90s further
inland. Increasing moisture on Wednesday will bring max heat index
values to just below Heat Advisory levels in the 100-105 F range.
With increased storminess and cloud cover, highs on Thursday will
be in the upper 80s along the coast to the low-mid 90s inland.
Overnight lows will be in the 70s.

&&

.LONG TERM...
(Friday through Monday)
Issued at 329 AM EDT Tue Jun 24 2025

The wetter pattern continues into early next week. At the surface,
the high pressure ridge axis will shift southward across the
region causing the flow to shift to west-southwesterly into the
weekend. The upper low over the FL peninsula then meanders across
the NE Gulf coast region into Saturday maintaining moist and
unstable Gulf air across the area. The upper low begins to open up
and weaken late Saturday into Sunday, but lingering dynamics and
deep moisture will continue to bring elevated daily rain chances
through early next week. With WSW steering flow, the Gulf coast
sea breeze becomes dominant with the sea breeze merger likely
along the I-95 corridor each afternoon/evening. Daytime highs will
range from the upper 80s to low 90s.

&&

.AVIATION...
(06Z TAFS)
Issued at 136 AM EDT Tue Jun 24 2025

IFR visibilities are expected to develop during the predawn hours
at VQQ. MVFR visibilities are likely to develop around sunrise at
JAX and CRG. A brief period of MVFR visibilities cannot be ruled
out at GNV, SSI, and SGJ around sunrise, but confidence was too
low to indicate in the overnight TAFs. VFR conditions should
otherwise prevail before 14Z Tuesday at the regional terminals.
Light and variable winds will continue through around 15Z,
followed by northeasterly surface winds becoming sustained around
5 knots inland and 5-10 knots at SGJ towards noon, while westerly
winds around 5 knots develop at SSI after sunrise. Surface winds
will then shift to easterly by 18Z, with speeds generally
increasing to around 10 knots at the regional terminals. Surface
winds will then shift to southeasterly at 5-10 knots towards
sunset.

&&

.MARINE...
Issued at 329 AM EDT Tue Jun 24 2025

High pressure centered along the southeastern seaboard will
gradually weaken while shifting southward over our local waters
through midweek. Light onshore winds will prevail, with dry weather
continuing through Tuesday evening. Isolated to widely scattered
showers and thunderstorms are forecast on Wednesday, mainly across
the northeast Florida waters. Atlantic high pressure will then
build westward across the Florida peninsula on Thursday and
Friday as weak troughing settles over the southeastern states.
Prevailing winds will become southwesterly, with afternoon sea
breezes continuing over the near shore waters. Chances for showers
and thunderstorms will increase late this week and into the
upcoming weekend, with strong storm potential during the afternoon
and evening hours. Seas of 2 to 3 feet will prevail both near
shore and offshore during the next several days.

Rip Currents: Onshore winds will combine with a persistent
easterly ocean swell to create a lower end moderate risk at the
northeast FL beaches today. Low surf heights will yield a low risk
at the southeast GA beaches. Similar conditions will prevail on
Wednesday.

&&

.FIRE WEATHER...
Issued at 329 AM EDT Tue Jun 24 2025

An unseasonably dry air mass will linger over our area today,
allowing inland humidity values to fall to the 35-40 percent range
during the afternoon hours. Meanwhile, easterly surface and
transport winds will prevail area-wide through midweek, followed
by winds shifting to southeasterly on Thursday. Elevated mixing
heights will yield good daytime dispersion values across
inland portions of southeast GA, while high values are expected
for locations along and west of U.S. Highway 301 in northeast and
north central FL this afternoon. Fair daytime dispersion values
are forecast for locations east of I-95 through Thursday.
Elevated mixing heights will continue at inland locations on
Wednesday and Thursday, creating good to marginally high daytime
dispersion values for locations along and west of I-95.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  98  73  97  72 /  10  10  20  20
SSI  90  76  90  76 /  10  10  10  10
JAX  95  72  94  73 /  10  10  20  10
SGJ  90  73  90  73 /   0  10  20  10
GNV  98  72  95  72 /  10  10  40  20
OCF  96  72  94  72 /  10  10  50  20

&&

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

$$