355
FXUS62 KJAX 281822
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
222 PM EDT Fri Jun 28 2024

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

.NEAR TERM...
Issued at 218 PM EDT Fri Jun 28 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

Thunderstorms are develop over duval county as initial round of
showers/isolated T`storms have progressed off the St Johns and
Flagler county coastlines pushing some outflow boundaries north.
Expect numerous thunderstorms to affect downtown Jacksonville,
the Jax beaches with further developments north along I-95/US17
corridors into SE GA. Slow storm motion and above normal moisture
levels will create locally heavy rainfall amounts that will
create minor flooding over urban and low lying areas. AS mid
level temperatures are warmer than typical for late June around
-6C, not expecting severe downburst winds, but strong wind gusts
 40-50 mph are most likely with strongest convection into mid
 afternoon. However, frequent lightning will occur with storms due
 to strong diurnal heating and a very moist airmass as dewpoints
 are commonly ion the mid 70s. A funnel cloud or waterspout may
 develop briefly as storms initially tower along the Atlantic
 seabreeze or outflow boundaries, but the environment overall does
 not support a threat for tornadoes. Highs have already peaked in
 the low 90s and will likely remain steady or fall with clouds
 and convection increasing over next few hours.

Tonight, leftover T`storm outflow boundaries may push north into
SE GA areas closer to the Altamaha river basin in the early evening
hours with mostly cloudy skies from mid and high level debris
clouds thinning out gradually overnight. Lows will range into the
low 70s for inland SE GA, mid 70s over inland NE FL, and the upper
70s along the coast.

&&

.SHORT TERM...
(Saturday through Sunday night)
Issued at 218 PM EDT Fri Jun 28 2024

Deep moisture will remain entrenched across the region through the
weekend, supporting diurnal convection each afternoon. Steering flow
will begin to weaken and become stagnant as low-level ridging
consolidates over then northern GOMEX and an easterly wave aloft
slowly slides into the southern FL peninsula. Given the lack of
flow, both sea breezes will progress inland and collide between I-75
and HWY-301 each afternoon; the St Johns River breeze and its
interaction with the Atlantic sea breeze will also be a focus for
more robust convection.

As far as instability is concerned, there will be enough (MLCAPE
values peaking between 1500-2000) to support a few strong pulse
storms each day. It`s unlikely that the somewhat cooler temps aloft
associated with the easterly wave will extend far enough north into
NE FL to further amplify instability. The primary storm concerns
will be strong, gusty outflows. Localized flooding, especially in
urban areas, will also be a threat as storm motions will be very
slow (<5mph) and even stationary at times. PWATs remaining around
the 90th percentile (2"+) may yield rain rates between 3-5" per
hour.

Anticipate convection to wane after sunset on Saturday, with perhaps
a few lingering showers or isolated storms inland through the mid
evening. Similar trends are expected across NE FL Sunday night as
well but convection may last later into the night across SE GA as
outflow from local diurnal convection interacts with a prefrontal
trough pushing southward through GA.

Hot and humid conditions persist through the weekend with highs in
the low to mid 90s inland and in the upper 80s to low 90s at the
beaches thanks to a more active sea breeze pushing across the mild
waters (shelf water temps now in the mid 80s). Humidity will push
the "feels like" (Heat Index) temps into the 100-107 range each day,
just below Advisory levels.

&&

.LONG TERM...
(Monday through next Friday)
Issued at 218 PM EDT Fri Jun 28 2024

Anomalous deep moisture continues and increases with pooling
ahead of a slowing front that should stall to the north early next
week. Weak surface troughing within the vicinity of the decaying
boundary will be a convective focus Monday across SE GA before
dissipating entirely through Tuesday. Numerous showers and
afternoon storms are likely through Wednesday before drier air
attempts to wrap around the eastern side of an intense upper
ridging by Independence Day, limiting storm coverage along the
sea breezes. Temperatures will be around or perhaps below normal,
especially across SE GA, to start the week due to convective
activity and associated cloudiness. Under the influence of the
intense ridge, temperatures should begin to push above normal by
Independence Day and into next weekend.

&&

.AVIATION...
(18Z TAFS)
Issued at 128 PM EDT Fri Jun 28 2024

The 18Z TAF forecast will begin with tempo MVFR restrictions for
ceilings/visibility and gusty winds up to 30 knots at duval
county and SSI terminals over the 18-22Z window as thunderstorms
develop quickly between collision of the Atlantic seabreeze and
initial scattered showers/isolated thunderstorms from the
southwest associated with Gulf seabreeze. Storms will wrap up by
21Z at GNV but VCTS will linger around 00Z along the NE FL coastal
TAF sites up to SSI. VFR conditions prevail late tonight and into
Saturday. Light variable winds become calm inland overnight under
thinning cloud cover. High pressure ridge just south of the
region will allow for lighter and variable winds to start Saturday
with the Atlantic Seabreeze moving onshore again after 15/16Z
Saturday with VCTS noted to end the period at all terminals as
scattered ceilings rise from 2.5 kft to 3.5 kft.

&&

.MARINE...
Issued at 218 PM EDT Fri Jun 28 2024

High pressure ridging south of the waters will promote south
to southwesterly winds into early next week. Scattered to numerous
showers and thunderstorms will develop along the near shore waters
each afternoon and linger into early evening each day due to storm
growth along the Atlantic seabreeze. Impacts from thunderstorms
will include wind gusts up to 30 to 35 knots in stronger storms
along with brief waterspouts. but may be locally higher in
storms. A cold front will approach the waters, then dissipate
Wednesday with winds more east to southeasterly.

Rip Currents: A low end moderate risk of rip currents will be in
place this afternoon/evening behind the Atlantic seabreeze for our
NE FL and SE GA beaches. A low end moderate risk will again be in
place Saturday at all area beaches.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  93  73  94  76 /  70  50  40  30
SSI  90  76  90  78 /  60  40  40  40
JAX  92  74  93  76 /  80  60  60  30
SGJ  92  74  91  76 /  80  50  60  40
GNV  91  73  92  73 /  80  40  70  30
OCF  92  73  92  75 /  80  40  70  30

&&

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

$$