961
FXUS62 KJAX 121723
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
123 PM EDT Fri Jul 12 2024

...New AVIATION...

.UPDATE...
Issued at 828 AM EDT Fri Jul 12 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

Forecast on track for mostly sunny and hot conditions today as
Northwest steering flow around weak low pressure system drifts
northward towards the Carolinas today. This flow pattern will keep
the hot conditions in place and with PWATs only around 1.5 inches
any afternoon/evening convection will remain suppressed with
rainfall chances only in the 10-30% range and well below mid July
normal levels. Best chances for an isolated storms will be on the
weak East Coast sea breeze front as it pushes slowly inland to the
I-95 corridor. Short range models are showing the best coverage
across coastal SE GA counties as some deeper moisture is expected
to wrap around the weak low pressure system pushing into the
Carolinas. The NW steering flow will push Max temps into the
middle to some upper 90s over inland areas with peak heat indices
of 100-105F, while the East Coast sea breeze should push inland in
time to keep the Atlantic Coastal areas in the lower to some
middle 90s, but the slightly higher dewpoints/low level moisture
will allow for peak Heat Indices to top out around 105F. Any late
afternoon/evening convection should fade quickly after sunset with
fair skies and typical low temps in the lower/middle 70s inland
and upper 70s/near 80 along the Atlantic Coast.

&&

.NEAR TERM......(Today through Saturday)...

The weak surface low pressure rotating over the coastal Atlantic
waters, about 150 miles east of Fernandina Beach, will slowly lift
northward toward the Carolinas today. As it does this maneuver,
it will begin to fill as it decouples from the influence upper low
to the south. The frontal zone tethered to the low will lift
northward as well, allowing backing low-level flow to advect
moisture pooled across the northeastern Gulf eastward and into the
region. Overall only isolated to widely-scattered coverage of
mainly low-top showers and a handful storms are expected this
afternoon. Best chances (around 20-30%) will be at the coast and
along I-95 where moisture should be enough to generate marginal
instability. However, given the mid level lapse rates expected,
potential for deep or strong storms will be quite low. Tonight,
quiet conditions under partly clear skies will prevail as ridging
aloft centers itself overhead.

On Saturday, Moisture steered by a weak southerly flow will trend
PoPs and storm coverage upward (40-70%), mainly across NE FL and
south of I-10. Amid the weak flow, sea breezes will push inland
from the Atlantic and Gulf, setting the stage for a merger around
the Highway 301 corridor. Slow storm, or outflow dominant, motion
combined with deep layer moisture (PWATs around 2") will lead to
localized minor flood potential. Fortunately the 2-day break in
convection has allowed the ground to soak in recent rains and
significant flooding concerns are low.

Temperatures will read in the mid and upper 90s today but
dewpoints will mix out, keeping heat index more tolerable today
and Saturday (upper 90s and low 100s).

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

&&

.SHORT TERM...(Saturday night through Sunday night)

Remaining convection weans through the first half of Saturday
Night, with a mild night in the mid to upper 70s and near 80 at
the coast and St. Johns. An upward trend in chances for showers
and t`storms continues into Sunday with a weak southerly flow
regime, and PWATs starting to creep back up from south to north as
a frontal boundary just north of the CWA lifts further northward.
Highest POPs will be with the sea breeze collisions over
northeast FL, with some drier air still lingering a bit the
further north you go. High temps Sunday will remain a bit above
average, mainly in the mid 90s and some upper 90s over the
interior. Dew points will be creeping up into the 70s for most,
but likely still low enough to remain just below any heat advisory
criteria. Convection similarly dissipates into Sunday Night with
lows once again in the mid to upper 70s to near 80.

&&

.LONG TERM...(Monday through Thursday)

A pretty stagnant weak flow regime continues to start the next
work week, and through most of the long term as a whole. Generally
broad high pressure over the area starts to slowly shift further
eastward into the Bermuda High by mid to late week, which should
keep up the south to southeasterly flow with the westward extent
of a surface ridge more directly over the area and PWATs of 2
inches or higher in place over the entirety of the area. Temps
will remain above average for this period, though trending
slightly downward each day.

&&

.AVIATION...
(18Z TAFS)
Issued at 118 PM EDT Fri Jul 12 2024

Still VFR at all TAF sites, but Cumulus field starting to become
more SCT-BKN in the 4000-5000 ft range with cirrus above this
afternoon and still some hope that enough moisture and instability
will produce some widely scattered convection with best chances at
SSI and will keep VCTS there, while a bit lower chances expected
at NE FL TAF sites and likely only expect to get a few isolated
showers there so will go with VCSH for now, with any activity
expected to fade around sunset in the 00-01Z time frame. Rest of
the TAF period looks VFR for the most part, except for the usual
MVFR BR chances at VQQ around sunrise. Any lower clouds or
convection not really expected Saturday morning before the end of
the current TAF period and can likely be added with the next
forecast package.

&&

.MARINE...

No significant maritime weather concerns are expected through the
weekend and into next week. A weak surface low offshore will lift
northward into the Carolinas today where it will dissipate
through the weekend as broad high pressure regains prominence
across the waters. From Sunday onward, the stagnant high pressure
pattern will change very little, with a predominant southerly flow
in place and afternoon sea breezed development. Seas will
gradually build through the weekend as a modest onshore swell
reaches the First Coast.

Rip Currents: A Moderate Risk will develop this afternoon with
the sea breeze at NE FL beaches. A Low Risk is expected at SE GA
beaches. Moderate risk is expected at all beaches this weekend as
surf builds to 2-4 ft.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  97  74  96  75 /  20  20  10   0
SSI  92  80  93  80 /  20  20  20  10
JAX  97  76  96  77 /  20  20  40  10
SGJ  96  77  93  77 /  20  20  40  20
GNV  97  74  93  74 /  20  20  60  10
OCF  95  74  93  75 /  30  20  60  20

&&

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

$$