800
FXUS62 KJAX 050544
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
144 AM EDT Fri Jul 5 2024

...New AVIATION...

.NEAR TERM...
Issued at 114 PM EDT Thu Jul 4 2024

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

The frontal boundary/surface trough is quickly becoming more
diffuse this afternoon and looking at radar and visible satellite
imagery the Atlantic Sea Breeze front is becoming active with
convection firing between the ocean and St Johns River/U.S. 301 in
GA. The Gulf sea breeze is still west of U.S. 19 and have delayed
activation of that boundary until later this evening. Have
tweaked the forecast to reflect the east coast convection slowly
moving inland and converging near I-75 later this evening.

&&

.SHORT TERM...
(Friday through Saturday night)
Issued at 214 PM EDT Thu Jul 4 2024

Drier air will filter into the coastal zones Friday and linger
through Saturday which will limit convection along the I-95 corridor
each afternoon and focus t`storms inland where abundant deep
moisture will exist. Light steering in place will allow sea
breezes to push in from both coasts, but the Atlantic sea breeze
will be a bit more dominant. Numerous showers and storms are
likely to focus between Highway 301 and the I-75 corridor each
afternoon and evening. A slow- moving front will drift in from the
northwest Saturday and become another focus for convective
activity. No supportive kinematics in place to favor much of any
severe threat either afternoon, but strong pulse storms between
outflow/cellular mergers may lead to brief, sub- severe
downbursts. With deep moisture entrenched across the area,
concerns with developing storms will be localized flooding due to
hefty rainfall rates (3-5" per hour) and slow movement.

Ridging aloft, which has been responsible for the heat wave across
portions of the Southern US, will build eastward and overhead into
the weekend resulting in slightly warming temps into the mid 90s and
heat index between 100-110F each afternoon. Heat Advisories will
need to be considered.

&&

.LONG TERM...(Sunday through next Thursday)
Issued at 214 PM EDT Thu Jul 4 2024

No signs of much considerable changes in this stagnant flow pattern
with ample moisture in place to fuel afternoon thunderstorms on the
sea breeze each day. A decaying boundary/trough axis will be in
place for the first couple of days next week and serve as focus for
storm development until it erodes by Wednesday. Another frontal
feature appears to work toward the area again by late next week. Hot
and humid conditions continue with no relief in sight as the strong
ridging aloft remains anchored over the area. Temps and heat index
values will stay above climo (average heat index is around 101F for
JAX) through the period with heat headlines possible each day.

&&

.AVIATION...
(06Z TAFS)
Issued at 136 AM EDT Fri Jul 5 2024

The combination of shallow ground fog from recent rainfall after
sunset and smoke due from evening fireworks created early MVFR to
IFR restrictions at CRG, VQQ and JAX...with a transient low
cieling deck recently reported at SSI. Best potential for IFR to
LIFR will continue at VQQ through sunrise with MVFR at JAX. Muggy
overnight conditions will bring hazy skies to other terminals with
rain free conditions through 14z and light to near calm winds
inland with a weak land breeze SSW 4-6 kts expected at coastal
terminals under passing mid level debris clouds.

Rain chances increase across inland terminals 16-18z with airmass
convection popping between slow moving, inland progressing sea
breezes. VCSH was indicated for coastal terminals 18-19z, with the
best chances of TS focused toward VQQ and GNV 17-20z where higher
rain chances are expected. Convection will be slow moving and
erratic in motion given weak steering flow, with precipitation
gradually fading across inland zones 23-03z with clearing skies at
coastal terminals through 00z and SE winds trailing the east
coast sea breeze.

Rainfall will tapper off through 06z with winds becoming light and
variable under lingering debris clouds.

&&

.MARINE...
Issued at 214 PM EDT Thu Jul 4 2024

A weakening frontal boundary will move southward and dissipate
over the local waters through the evening. Prevailing onshore
winds will continue as high pressure lingers off the eastern
seaboard. Storm coverage will decrease Friday through Saturday,
with the flow pattern shifting offshore direction during the
weekend. A slowing frontal boundary will approach the waters from
the north over the weekend and weaken across the waters next week.

Rip Currents: Given the enhanced risk on the Holiday, maintained
a high risk level for rip currents at NE FL beaches this
afternoon. Risk will be moderate Friday. At SE GA beaches, a
moderate risk continues.

&&

.CLIMATE...
Issued at 400 AM EDT Thu Jul 4 2024

Above average max/min temps expected through Saturday with the
record high mininim not too far off the forecast min temps
in the mid 70s.

July 5:
KGNV: 75/2023

July 6:
KJAX: 79/1902
KGNV: 78/1900

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  95  76  94  75 /  40  20  80  40
SSI  90  79  91  79 /  10  10  50  30
JAX  95  76  95  75 /  20  10  60  20
SGJ  91  77  93  77 /  10  10  40  20
GNV  93  74  93  74 /  50  10  70  20
OCF  93  75  94  75 /  60  20  70  20

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk until 4 AM EDT early this morning for
     FLZ124-125-133-138.

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

$$