868
FXUS62 KJAX 201954 CCA
AFDJAX

Area Forecast Discussion National Weather Service Jacksonville FL
258 PM EDT Fri Sep 20 2024

...New NEAR TERM, SHORT TERM, LONG TERM, AVIATION, MARINE,
HYDROLOGY...

...DRIER WEEKEND WITH CONTINUED TIDAL FLOODING AND INCREASED RIP
CURRENT RISK...

.NEAR TERM...
Issued at 228 PM EDT Fri Sep 20 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

Widely scattered showers still expected across NE FL/Coastal SE GA
this afternoon as the East Coast sea breeze pushes inland and
Northeast winds increase to 10-15G20 mph, and while an isolated
thunderstorm cannot be ruled out, storm chances remain around 10% or
less through sunset. Light Northeast flow will remain in place
tonight as weak high pressure builds north of the region, with winds
remaining in the 5-10G15 mph range along the Atlantic Coast, but
falling to 5 mph or less over inland areas under Mostly clear skies.
This may be enough onshore flow to push a few of the showers over
the Atlantic Coastal waters into the NE FL beachfront locations
towards sunrise Saturday morning, but overall rainfall chances
tonight remain along the coast remain around 20% or less.
Further inland expect winds to become near calm towards sunrise
Saturday morning & under mostly clear skies and temps falling into
the upper 60s, expect at least some patchy fog development from the
US 17/301 corridors inland to the I-75 corridor but too early to
determine location of any locally dense fog development. Closer to
the Atlantic Coast the onshore will keep milder conditions with lows
in the lower/middle 70s.

&&

.SHORT TERM...
(Saturday through Sunday night) Issued at 228 PM EDT Fri Sep 20 2024

Breezy east to northeast winds and drier conditions will prevail
this weekend with high pressure northeast of the region and weak
coastal troughs offshore of the local Atlantic seaboard. The best
chance of coastal showers will focus along the northeast FL Atlantic
coast, with rain chances shifting inland into the afternoons where a
thunderstorm will be possible generally south of a St. Augustine to
Gainesville line. With drier air in place and mostly clear skies
overnight, patchy to areas of inland fog are expected each night.
High temperatures will trend near to above normal values in the 80s
with mild lows in the upper 60s to low 70s.

The main weather impact this weekend will be a continuation of Tidal
Flooding along the local Atlantic coast, ICWW and within the St.
Johns River basin. Most locations will top out in the "Minor" tidal
flooding category, with a few locations along the St. Johns basin
from Mayport toward the Trout River potentially nearing the
"Moderate" threshold. At this time, the Coastal Flood Advisory to
highlight mainly nuisance tidal flooding around high tides continues
through the weekend.

&&

.LONG TERM...
(Monday through next Friday) Issued at 228 PM EDT Fri Sep 20 2024

Mon & Tue...A drier pattern continues through mid-week with a
warming trend as an upper level ridge builds across the Gulf Coast
region with a dry NNW flow aloft keeping frontal systems well north
of the area and PWAT falling to < 1.2 inches by Tuesday. At the
surface, the surface ridge will build southward with a ridge axis
extending across the local area Monday and Tuesday continuing a
dominant ESE flow and east coast sea breeze. Temperatures will
moderate above normal values with highs in the low 90s well inland
to mid 80s coast, with seasonally cool lows given the dry air with
values in the mid 60s to low 70s.

Wed & Thu...Moisture begins to return with a focus on the Gulf of
Mexico and the ultimate evolution and track of a potential tropical
system. Regardless of exact track, for the local area rain chances
begin to increase with high temperatures trending lower with the
increase in cloud cover and storminess. Use this weekend to restock
supply kits and review family evacuation plans.
Monitor official tropical forecasts from the National Hurricane
Center at hurricanes.gov and local emergency management officials.

&&

.AVIATION...
(18Z TAFS) Issued at 119 PM EDT Fri Sep 20 2024

Northeast flow, diurnal heating and just enough moisture have
allowed for some Towering Cu development and isolated showers (VCSH)
along the East Coast sea breeze and have added to a few of NE FL TAF
sites of JAX/VQQ/GNV for this afternoon, but this activity should
end at JAX by 20Z, at VQQ by 21Z and sunset at GNV and continued to
leave out any TSRA mention since chances remain low at this time
(<10%). Light to near calm winds over inland TAF sites will support
some fog formation in the 06-09Z time frame with IFR conds expected
at VQQ and MVFR conds at GNV/JAX, but remaining VFR at the coastal
TAF sites, lowest vsbys expected around sunrise. Conds improve in
the 13-14Z time frame back to VFR conds and another more significant
increase in NE winds late in the period will bring the chances for
isolated showers (VCSH) to SGJ in the this period with potential for
some MVFR CIGS as well.

&&

.MARINE...
Issued at 228 PM EDT Fri Sep 20 2024

Northeast winds will increase over the local waters tonight as an
area of high pressure builds northeast of the region. As winds and
seas increase late tonight into Saturday, Small Craft Exercise
Caution conditions are expected. By Sunday, winds veer onshore as
the high weakens and build ENE of the region. A weak pressure
pattern develops Monday and continues through mid-week as high
pressure extends offshore of the southeast Atlantic coast.

Rip Currents: There will be a moderate risk of rip currents today
with risk increasing to High by Saturday as surf heights rise amid
the breezy onshore flow.

&&

.HYDROLOGY...
Issued at 228 PM EDT Fri Sep 20 2024

Minor coastal (tidal) flooding is will continue through the weekend
for the Atlantic, ICWW and St. Johns River basin where a Coastal
Flood Advisory is in effect. Flooding impacts will be mainly
nuisance tidal flooding and greatest around times of high tide. High
tide crests and inundation extended will subside Sunday into into
Monday for most locations as astronomical departures decrease and
onshore flow weakens.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  67  87  67  89 /  10   0   0   0
SSI  73  82  73  84 /  10   0   0   0
JAX  70  85  72  88 /  10  10  10  10
SGJ  73  85  74  86 /  10  20  10  10
GNV  69  88  70  90 /  10  10  20  10
OCF  70  90  72  91 /  10  20  20  10

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 5 AM EDT Sunday for FLZ033-038-124-
     125-132-133-137-138-225-325.

GA...Coastal Flood Advisory until 5 AM EDT Sunday for GAZ154-166.

AM...None.
&&

$$