501
FXUS62 KJAX 261033
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
633 AM EDT Wed Jun 26 2024

...New AVIATION...

.NEAR TERM...
Issued at 322 AM EDT Wed Jun 26 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

Light southerly flow today will allow the sea breezes to develop
and push inland, with highs soaring into the mid to upper 90s
inland, with slightly cooler temps along the coast. Heat indices
will climb into the 105-112 degree range this afternoon during
peak heating, prompting a Heat Advisory issuance along the
Atlantic coast north of St. Johns county and in the St. Johns
river basin, as well in the Suwannee valley area.

Showers and thunderstorms will fire up along the Gulf sea breeze
in the late morning/early afternoon hours, and progress inland,
later interacting with the east coast sea breeze and sparking up
numerous showers with embedded thunderstorms over NE FL. The
primary hazards will be gusty winds and locally heavy rainfall as
PWATs rise above 2.0" across NE FL. With drier air over most of SE
GA, precipitation will be more limited, and heat indices will be
lower for inland areas as opposed to NE FL. Convection will taper
off after sunset with the loss of diurnal heating, lows will stay
mild in the mid 70s.

&&

.SHORT TERM...
(Thursday through Friday night)
Issued at 322 AM EDT Wed Jun 26 2024

Troughing aloft will dig across the southeastern states on Thursday,
with southwesterly flow deepening ahead of a decelerating frontal
boundary that will stall across southeast GA by Thursday night.
Convection will likely get an early start along the FL Nature and
Big Bend coasts, with scattered showers and thunderstorms then
filling in across the rest of the Suwannee Valley and north central
FL during the late morning hours as the Gulf Coast sea breeze gets
propelled quickly inland. Additional forcing from the approaching
frontal boundary and mesoscale boundary collisions should result in
numerous showers and thunderstorms across the rest of northeast and
north central FL, mainly during the early to mid afternoon hours,
while convection likely increases in coverage across southeast GA
during the mid to late afternoon hours along and ahead of the
frontal boundary. Strengthening low level southwesterly flow will
delay the development of the Atlantic sea breeze boundary until the
mid-afternoon hours, with this boundary remaining pinned east of
I-95 through late afternoon, allowing for another day of highs in
the mid 90s all the way to the coast in northeast FL and southeast GA,
while late development of of convection allows for highs to reach
the upper 90s for locations north of Interstate 10. Maximum heat
index values will again approach Heat Advisory criteria, especially
for the coastal counties, where convection will likely not arrive
until the mid afternoon hours.

Storms may pulse and briefly become strong, especially at coastal
locations near the pinned Atlantic sea breeze boundary and also
across inland southeast GA near the frontal boundary, with stronger
storms being capable of producing downburst winds of 40-50 mph
along with frequent lightning strikes and briefly heavy downpours.
East-northeasterly storm motion should be faster than in previous
days, reducing overall rainfall amounts for our area.

Convection may linger into the evening hours on Thursday for
locations closer to the frontal boundary in southeast GA. Activity
should diminish before midnight, with debris cloudiness gradually
thinning overnight. Another round of predawn convection is expected
to develop along the FL Big Bend and Nature Coasts on Friday, with
convection possibly moving across north central FL and the Suwannee
Valley around sunrise. Lows will generally fall to the mid 70s inland
and the upper 70s at coastal locations.

Troughing aloft will begin to de-amplify across the southeastern states
on Friday as "Heat Wave" ridging expands eastward from Texas and the
lower Mississippi Valley. Southwesterly low and mid-level flow will
continue across our region as the frontal boundary dissipates near the
FL/GA border. Convection will again be driven initially by the inland
moving Gulf coast sea breeze, with scattered showers and thunderstorms
likely progressing across the I-75 corridor during the mid to late
morning hours, reaching the I-95 corridor in northeast FL by early
afternoon. Convection should then increase in coverage across southeast
GA during the mid to late afternoon hours along the dissipating frontal
boundary. Mid-level temperatures will remain mild and east-northeasterly
storm motion should remain brisk, with convection potentially pulsing
as it encounters the pinned Atlantic sea breeze boundary along the I-95
corridor in northeast FL early in the afternoon, while pulsing storms
then shift to southeast GA during the mid to late afternoon hours. Highs
will generally reach the low to mid 90s area-wide, with heat index
values expected to remain just below Heat Advisory criteria (108 degrees).

Showers and thunderstorms may diminish more quickly on Friday evening
as ridging aloft builds into our region and the axis of Atlantic surface
ridging begins to lift northward across the FL peninsula, resulting in
weakening southwesterly low and mid level flow. Lows again will fall
to the mid 70s inland and the upper 70s to around 80 at coastal
locations.

&&

.LONG TERM...
(Saturday through Tuesday)
Issued at 322 AM EDT Wed Jun 26 2024

Ridging aloft will briefly build into the southeastern states this
weekend before retrograding westward early next week as troughing
progresses across the Great Lakes states and New England early next
week. The axis of Atlantic high pressure will lift northward this
weekend, creating a south-southeasterly low level flow across our
region. This change in the flow pattern will allow for the Atlantic sea
breeze boundary to progress further inland, setting up a collision
with the Gulf coast sea breeze for locations along and west of U.S.
Highway 301 on Saturday and Sunday afternoons, where numerous
thunderstorms are forecast. Scattered convection will otherwise be
possible along these inland moving mesoscale boundaries, with
showers and thunderstorms generally diminishing at inland locations
during the mid to late evening hours. Ridging aloft will allow inland
highs to soar to the mid to upper 90s, with coastal highs remaining
closer to 90 as the sea breeze develops earlier in the afternoon hours.
Lows this weekend will generally fall to the mid 70s inland, ranging to
around 80 at coastal locations.

Troughing aloft diving southeastward towards the New England and
Mid-Atlantic coasts early next week will drive another weakening
frontal boundary into the southeastern states. Low and mid level
flow will veer to southwesterly as the axis of Atlantic high pressure
sinks southward, resulting in convection being driven by the inland
moving Gulf coast sea breeze across northeast and north central FL,
while numerous afternoon and evening thunderstorms develop across
southeast GA near the approaching frontal boundary. Stronger storms
will be possible along the I-95 corridor as convection potentially
intersects a pinned Atlantic sea breeze boundary. Long range guidance
indicates that troughing aloft will then progress offshore of the
Mid-Atlantic and New England coasts by late Tuesday, allowing ridging
to again build back into the southeastern states. Scattered to
numerous mainly afternoon and evening thunderstorms are expected again
on Tuesday as PWATs remain seasonably high and lighter southwesterly
low and mid level flow allows for convection to develop along inland
moving sea breeze boundaries. Highs will likely remain slightly above
seasonal averages early next week.

&&

.AVIATION...
(12Z TAFS)
Issued at 633 AM EDT Wed Jun 26 2024

VFR conditions expected at the TAF sites this morning, with
thunderstorms developing this afternoon. PROB30s are in place for
most of the TAF sites today for best timing of thunderstorms.

&&

.MARINE...
Issued at 322 AM EDT Wed Jun 26 2024

Fairly persistent troughing will be north northwest of the area
through the upcoming weekend. High pressure ridge will be east of
the region through Wednesday, then to the east southeast into
Thursday. The high will be located to the northeast Friday through
the weekend. Daily showers and thunderstorms will develop over
the local waters through the weekend.

Rip Currents: Moderate rip current risk for NE FL and SE GA
beaches today.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  99  74  96  74 /  30  10  50  30
SSI  91  77  93  79 /  30  10  50  30
JAX  95  74  96  75 /  50  20  60  20
SGJ  94  76  94  78 /  60  30  50  30
GNV  94  74  93  75 /  70  20  60  20
OCF  93  76  92  76 /  70  20  60  20

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory from noon today to 7 PM EDT this evening for
     FLZ021-024-033-120-124-125-132-133-220-225-232-325-425.

GA...Heat Advisory from noon today to 7 PM EDT this evening for
     GAZ153-154-162-165-166.

AM...None.
&&

$$