-- Discussion containing changed information from previous version are highlighted. --
239
FXUS62 KJAX 191255
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
855 AM EDT Thu Jun 19 2025

...A FEW STRONG TO MARGINALLY SEVERE PULSE STORMS ALONG THE I-95
CORRIDOR THIS AFTERNOON IN NE FL...

.UPDATE...

-- Changed Discussion --
The latest sounding profile is in! As predicted, a strengthening
and deepening southwesterly flow will prioritize a gulf breeze
advancement through the morning - convection is already
developing along the Big Bend at 0830. This flow will halt the
Atlc sea breeze, keeping it east of the I-95 corridor and this
corridor is where strong to marginally severe pulse storms may
develop. Buoyancy parameters are a tad bit stronger than yesterday
due to some slight cooling in the mid levels as the upper
ridging, which had been in place, is flattened by the downstream
trough.

Convective evolution will be on the earlier side than what is
typical. The strongest storms are still expected during the
afternoon but should fall between 3p-6pm with weakening trends
thereafter as storms pulse along the residual outflow boundaries.
The one feature that may perpetuate storms into the evening will
be a slowing and decaying cool front slowly sliding south across
central GA this evening. Outflow offered by convection along front
may continue isolated storms across portions of SE GA through and
possibly a little after midnight.

In addition to storms, it will be another seasonably hot summer day
as we approach the equinox (longest day of the year) tomorrow.
The southwest flow will pumps temps to the low 90s areawide, even
at the beaches. It`ll feel pretty hot today with heat index values
100+. Important to hydrate FREQUENTLY and take cooling/rest
breaks while working outdoors.
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&&

.NEAR TERM...
(Today through Tonight)
Issued at 205 AM EDT Thu Jun 19 2025

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

Deep flow will transition to a more southwesterly today as the sfc
ridge shifts a little southward and a mid level trough moves in
across GA, MS, and the parts of northern FL. PWATs will recover
over most areas from some low values from yesterday, with values
today of about 1.7 to 2 inches per GFS, NAM, and SREF. Slightly
lower values expected for far inland southeast GA near 1.5/1.6
inches. Lessened subsidence, ample moisture, and some cooling
aloft at 500 mb to -7C to -8C will lead higher chances today,
generally scattered to numerous coverage of showers and storms,
mainly focused along the I-75 corridor initially, then shifting to
the east coast and coastal waters in the afternoon. The main
threats will continue to be locally strong wind gusts, frequent
lightning, and heavy downpours. Having said that, there may be an
outside chance of a severe storm, given some low-end bulk shear
values of up to 20-25 kt, and the potential for higher CAPE today.
This isolated severe potential should generally be located from
eastern northeast FL zones up into coastal southeast GA, and to
near the Okefenokee swamp area. Timing from about 4 pm-9 pm.

Will show generally likely POPs across northeast FL and trending
down to 30-40 percent north of Waycross. Highs today will reach
into the lower to mid 90s with heat indices similar to prior days
about 100-105 for northeast FL and slightly lower values for
inland southeast GA where slightly lower dewpoints are expected.

Tonight, scattered convection is anticipated in the evening and
should generally dissipate overnight. After midnight, isolated
convection will be possible for offshore waters, and then the
second area over western parts of Gilchrist, Alachua, and Marion
counties as west/southwest flow brings in some weak convection
across from the Gulf. Otherwise, lows in the lower to mid 70s
anticipated again.

&&

.SHORT TERM...
(Friday through Saturday night)
Issued at 205 AM EDT Thu Jun 19 2025

Friday, A mid to upper trough axis will move east off of the
eastern seaboard with an associated surface cold front dragging
southward into the coastal plains of the Carolinas and near the
Altamaha river. Combination of additional moisture and frontal
convergence will create numerous to widespread showers and storms
across NE FL with slightly less coverage over SE GA. Isolated
strong to potentially severe T`storms will be possible as mid
level temperatures cool to below climatology levels of about
-9 to -10 Celsius with corresponding steeper mid level lapse
rates.

On Saturday, the mid/upper level trough axis will exit into the
Atlantic and the removal of shortwave energy aloft will cause the
front to slowly dissipate through the day. Meanwhile high pressure
will move from the OH and TN valley into the central and southern
Appalachians. Winds will be variable early and become easterly as
low level ridging reforms to the east over the Atlantic waters.
This pattern will scattered showers and thunderstorms near the
coast with numerous showers and storms west of highway 301 as
the Atlantic seabreeze pushes well inland.

Daytime highs will be in the mid 90s for most areas and low 90s
at the beaches. Overnight lows will be a little above normal in
the mid 70s along the coast and low to mid 70s inland. Heat index
values will top out in the 100-106 degree range.

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 205 AM EDT Thu Jun 19 2025

By the end of the weekend and into early next week, ridging aloft
will build over the OH valley into the Mid Atlantic states, with
surface high pressure reforming east the Southeast US coast and
promoting easterly flow over the area. This will allow for a great
reduction in pops with isolated T`storms confined to areas well
inland each afternoon. Skies will be mostly sunny east of highway
301 and partly cloudy further west.

Temperatures during the period will begin near normal with highs
in the low 90s away from the coast, upper 80s at the beaches and
low to mid 90s west of highway 301, then warm by midweek next week
to the mid 90s inland, low to mid 90s along I-95, and around 90 at
the beaches.

Heat index values will average 98-103 degrees during the period.

&&

.AVIATION...
-- Changed Discussion --
(12Z TAFS)
Issued at 758 AM EDT Thu Jun 19 2025

VFR conditions will persist as thunderstorms build from the Big
Bend of FL this morning and push eastward to the I-95 corridor
this afternoon, some storms may be strong to severe and capable of
gusts 35-40 kts, small hail, and erratic wind shifts. Convection
may reach KGNV as early as 15z and KJAX as early as 18z.
Anticipate convection to fade from 23-01z with leftover showers
inland drifting back to the Atlantic coast. A prevailing
southwesterly winds around 8-12 knots will keep the Atlc sea
breeze from reaching KJAX this afternoon but it is expected to
push into KSSI, KSGJ, and potentially KCRG through the early
afternoon before thunderstorms initiate. VFR conditions are
expected overnight.
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&&

.MARINE...
Issued at 205 AM EDT Thu Jun 19 2025

High pressure centered over the Atlantic and central Florida will
drift south through Friday while a weak front moves into the
southeast states. Scattered thunderstorms will be possible each
afternoon through early next week, and may result in hazardous
winds and seas. The front will dissipate over the weekend while a
weak ridge of high pressure builds across southeast Georgia early
next week. Winds will become gradually more south and southeast
late in the weekend and early next week but winds remain on the
low side (aob 15 kt) for most part.

Winds may reach near exercise caution criteria tonight but for
most part look to be just shy of headlines. Overall seas look to
be 2-4 ft and winds near or below 15 kt into early next week.

Rip Currents: Low to moderate rip current risk expected through
Friday with surf around or below 2 ft. Looks like longshore
currents still pulling northward given the prevailing flow of
recent.

&&

.PRELIMINARY POINT TEMPS/POPS...
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AMG  93  73  93  72 /  40  40  40  20
SSI  90  75  90  75 /  40  40  40  30
JAX  94  73  93  73 /  60  40  60  30
SGJ  91  74  91  74 /  60  40  60  30
GNV  93  73  94  73 /  70  30  80  40
OCF  92  73  93  73 /  70  30  80  40
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&&

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

$$