-- Discussion containing changed information from previous version are highlighted. --
403
FXUS62 KJAX 150141
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
941 PM EDT Tue May 14 2024

...New UPDATE...

.UPDATE...
-- Changed Discussion --
Issued at 939 PM EDT Tue May 14 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

Overall forecast is in good shape with only minor adjustments to
increase the QPF/rainfall forecast up a little for the predawn hours
and into midday as waves strong to isolated severe T`storms develop
after midnight tonight as a jet streak moves in from the Gulf. SW
surface winds 5-10 mph will remain overnight with increasing low
level southwest winds 40-45 knots head of a approaching cold front
will help to destabilize the environment late tonight and raise
elevated CAPE values towards 2,000 J/kg with about 500-800 J/kg of
CAPE within the Hail growth zone of -10C to -30C aloft aiding a
threat of potentially large hail with more intense storms. Strong
bulk shear values of 50 knots will also help support a gusty wind
threat 40-60mph along with heavy downpours that will bring more
than a an inch of rain for areas south of I-10 with locally heavy
rainfall amounts of 2-3 inches possible where heavier storms
develop. An isolated tornado threat cannot be ruled out either due
to the enhanced low level shear. Lows overnight will be above
normal in the upper 60s and lower 70s.

Showers and embedded thunderstorms will continue Wednesday morning
before shifting south and east to the NE FL coast by midday and then
ending for all areas by afternoon as the cold front moves into the
area and begins to slow it`s progression. Ahead of the front, winds
will be southwest 10-15 mph with gusts to 25-30 mph. Bumped up highs
a bit to account for convection ending a bit sooner Wednesday with
upper 80s for much of the area and cooler over north central FL
into the mid 80s where convection and clouds persist longer through
the early afternoon.
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&&

.SYNOPSIS...
Issued at 314 PM EDT Tue May 14 2024

Afternoon surface analysis depicts a warm front lifting northward
through the Carolinas and north GA, with a wavy cold front
extending from north to south across the Tennessee and Lower
Mississippi Valleys. Aloft...closed upper troughing centered
over the Mid-Mississippi Valley was moving slowly eastward, with
ridging centered over Cuba and the northwestern Caribbean Sea. This
weather pattern was creating deep southwesterly flow across our
area, with this flow propelling the shortwave trough and
associated weakening Mesoscale Convective System (MCS) that
impacted our area earlier this morning offshore and east of Cape
Canaveral this afternoon, with another MCS moving eastward across
the east central Gulf of Mexico, or south of the FL panhandle
coast, this afternoon. Subsidence in the wake of the departing MCS
was allowing for filtered sunshine to overspread our area this
afternoon from west to east, as thick debris cirrostratus cloud
cover along the I-95 corridor thins out as convection moves
further away from our area. Breezy south-southwesterly winds
prevail across northeast and north central FL in the wake of the
MCS, with lighter winds for locations north of Interstate 10.
Temperatures at 19Z were generally in the 80s area-wide, except
upper 70s beneath the thicker departing cirrostratus across
coastal Flagler County. Dewpoints were mostly in the upper 60s and
lower 70s throughout our region.

&&

.NEAR TERM...
(through Tonight)
Issued at 314 PM EDT Tue May 14 2024

Subsidence in the wake of the departing MCS should keep a lid on
convective activity across our region through the evening hours,
with a few showers possibly developing towards midnight ahead of
the next developing MCS that is expected to impact our region
overnight. This next MCS will be aided by a 90-knot jet streak at
250 millibars (around 35,000 feet) that will be developing at the
base of the trough that will be digging into the Tennessee Valley
overnight, which will also force a 40-50 knot low level
southwesterly low level jet around 850 millibars (around 5,000
feet) that will become aligned along the Interstate 10 corridor
towards sunrise. The digging trough will push a cold front
eastward across the FL panhandle overnight. Increasingly
divergent flow aloft as a result of strengthening winds aloft
should create an expanding area of convection along or just
north of the Interstate 10 corridor just after midnight tonight,
with an increasing potential for strong to isolated severe
thunderstorms expected during the overnight and predawn hours,
mainly across northeast FL.

Heavy downpours may extend into coastal southeast GA during the
overnight and predawn hours before convection begins a
southeastward push towards sunrise on Wednesday. The main threats
with strong to isolated severe convection overnight will be
downburst winds of 40-60 mph and hail, and an isolated tornado
cannot be ruled out, especially for locations south of I-10.
Widespread 1-2 inch rainfall totals will be possible by sunrise
for coastal southeast GA and the I-10 corridor before activity
shifts south of I-10 after sunrise. Lows tonight will only fall to
the upper 60s across inland southeast GA and lower 70s elsewhere.

&&

.SHORT TERM...
(Wednesday through Thursday night)
Issued at 314 PM EDT Tue May 14 2024

The active weather pattern continues through Wednesday, with
another round expected overnight tonight and through Wednesday
afternoon. Strong to isolated severe potential will be highest in
the morning south of I-10 with the primary hazards being gusty
winds, locally heavy rainfall, and isolated tornadoes. By early
afternoon, the bulk of the storms will be offshore/south of the
area, with lingering isolated thunderstorms possible through the
afternoon over north central FL. High temperatures will trend near
normal Wednesday, reaching the mid to upper 80s area-wide.

A brief break in this wet pattern is expected for Thursday as the
front sits just south of the area over central Florida. Clear
skies will allow for good daytime heating with highs reaching to
upper 80s to lower 90s. Beachside will be able to heat up into the
upper 80s/near 90 as well due to elevated west/northwest winds
preventing an east coast sea breeze from moving far inland.

&&

.LONG TERM...
(Friday through next Tuesday)
Issued at 314 PM EDT Tue May 14 2024

Precipitation chances will return Friday afternoon/evening and
last through Monday as the front lifts northward Friday,
followed by a trialing cold front incoming from the northwest this
weekend. The highest rain chances will be on Saturday ahead of
the frontal passage, numerous showers and isolated thunderstorms
are forecast. More uncertainty in the forecast comes on Sunday and
Monday, depending on where the front`s position is, for now
scattered rain and thunderstorm chances are in the forecast both
days. High temperatures will range from the mid 80s to lower 90s
each day during this period, with mild lows in the mid 60s to
lower 70s.

&&

.AVIATION...
(00Z TAFS)
Issued at 807 PM EDT Tue May 14 2024

The 00Z TAF period begins with lingering breezy southwest winds
10-15 knots with gusts 15-20 knots that should gradually subside
through 02Z to 8-10 knots under increasing high level clouds as
a shield of left over anvil from earlier Gulf storms moves over
the area. A wave of energy aloft will create rounds of strong to
isolated severe thunderstorms late overnight with increasing
coverage after 05-06Z from VCTS to steady showers and MVFR level
ceilings lowering to 2.5 kft through the morning hours. Strongest
thunderstorms will move through the terminals 08-13Z from west to
east with IFR level restrictions along with gusty winds up to
30-40 knots. There will be additional showers and storms that will
continue behind the main storms as the cold front nears from the
northwest. Showers and storms will diminish first from SSI by 14Z
through the Northeast Florida terminals 16Z-20Z with low and mid
level clouds decreasing as the front slides towards the coast with
breezy southwest winds mixing down in the wake of the showers and
storms as sunshine increases by early/mid afternoon 10-15 knots
with gusts up to 20-25 knots.

&&

.MARINE...
Issued at 314 PM EDT Tue May 14 2024

Southwesterly winds will strengthen overnight ahead of an
approaching cold front, with widespread showers and the potential
for strong to severe thunderstorms expected developing over our
local waters after midnight. Strong to severe thunderstorms will
be capable of producing damaging wind gusts, hail and waterspouts
late tonight and Wednesday morning. Activity will then shift
southeastward late on Wednesday morning as the frontal boundary
shifts southward. Outside of thunderstorm activity, winds will
increase to Caution levels of 15-20 knots throughout our local
waters by Wednesday morning, with Caution conditions continuing
offshore on Wednesday night. Seas of 3-5 feet are expected both
nearshore and offshore through Wednesday.

Conditions will improve from north to south on Wednesday
afternoon and evening as the frontal boundary shifts southward,
with breezy westerly winds expected outside of thunderstorm
activity that will gradually subside by Thursday afternoon as weak
high pressure settles over the southeastern states. Seas will
remain in the 3-5 foot range offshore on Wednesday night, with
near shore seas subsiding to 2-4 feet. Winds will then shift to
southerly on Friday ahead of the next frontal boundary that will
impact our area this weekend. Showers and thunderstorms will
likely impact our local waters from Saturday afternoon through
Sunday morning, with a few strong storms possible. Winds will then
shift to northwesterly by Sunday afternoon and night as this
front pushes offshore. Seas of 2-4 feet are expected throughout
our local waters from Thursday through the upcoming weekend.

Rip Currents: A southeasterly ocean swell and choppy surf
conditions will keep a lower end moderate risk in place at area
beaches through Wednesday. Light prevailing offshore winds should
result in a low risk by Thursday.

&&

.PRELIMINARY POINT TEMPS/POPS...
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AMG  68  88  65  88 /  50  20   0   0
SSI  72  88  69  86 /  70  50   0   0
JAX  71  88  67  90 /  90  60   0   0
SGJ  72  87  69  90 /  80  80   0   0
GNV  71  86  67  89 /  80  70   0   0
OCF  72  84  67  89 /  70  80   0   0
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&&

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

$$