444
FXUS62 KJAX 030811
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
411 AM EDT Wed Jul 3 2024

...LOCALLY HEAVY RAINFALL POSSIBLE TODAY AND THURSDAY...
...New NEAR TERM, SHORT TERM, LONG TERM, MARINE...

.NEAR TERM...
(Today through tonight)
Issued at 400 AM EDT Wed Jul 3 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

Frontal boundary stalled over southeast Georgia will gradually
weaken and diffuse today as surface high pressure off the mid-
Atlantic coast extends southward. Prevailing flow will be
predominantly out of the east today as upper level high pressure
ridging over the southeast US moves further into the Atlantic.
Showers and storms will build in the afternoon with a potential
for heavy rainfall as the moist air mass remains over the forecast
area with PWATs measuring between 2.2 and 2.5 inches, with storms
initially developing near I-95 and building inland as the
afternoon progresses and then becoming more dispersed in the
evening and overnight hours. High temperatures today will rise
into the lower to mid 90s for inland areas and in the upper 80s
and lower 90s along the coast. Overnight low temperatures are
expected to drop down into the mid 70s for inland areas and in the
upper 70s and lower 80s along the coast. Heat index values will
rise to be above 100 degrees today for some areas but are not
expected to reach Heat Advisory levels this afternoon.

&&

.SHORT TERM...
(Thursday through Friday night)
Issued at 400 AM EDT Wed Jul 3 2024

For Independence Day, weak and diffuse frontal boundary looks to
be located near the FL/GA state line with low level convergence,
PWATs near 2 inches, and west and east sea breezes pushing inland
to support scattered to numerous showers and storms, with heaviest
concentration/coverage at about 70 percent across inland northeast
FL where the best low level forcing will be located. Drier air in
the mid levels advecting in from the northeast will support lower
coverage across portions of eastern GA. Highs in the lower 90s
expected with heat indices generally 104-108, and so continues to
suggest just shy of a widespread heat advy conditions. Main t-storm
threats will be gusty winds and very heavy rainfall/localized
flooding potential given the high moisture content and slow storm
motion to the south to southwest.

Thursday night, sfc high pressure builds in from the northeast and
east. Low level convergence inland and residual daytime instability
will support isolated to scattered convection during the evening
hours. Convective activity should fade by midnight. Lows continue
from the mid 70s inland to upper 70s near the coast.

Friday, the frontal boundary is no longer noted in the guidance and
general sfc high pressure ridge is over the region. Mid level ridge
will be just west of the area, and mean deep layer winds are only
about 5 knots. Best moisture is located inland with PWATS near 2 inches,
and this is where we have the best rain chances at 40-60 percent,
and tapering to 30-40 percent near the coast. West and east sea
breezes, and daytime heating will be the main drivers of diurnal
convection. Max temps will be inched 1-2 degrees given the greater
daytime insolation. Friday night, some isolated inland convection
is possible, but should fade quickly during the evening hours.
Lows in the mid to upper 70s expected.

&&

.LONG TERM...
(Saturday through Tuesday)
Issued at 400 AM EDT Wed Jul 3 2024

Essentially little change in the thinking with the mid to upper
level ridge over the southeast states initially for the weekend,
and then shifts slightly south-southeast by Monday and Tuesday as
some mid level troughing digs in AL and GA. Weak sfc ridge will
be over the region through the weekend, and then build slightly
on Monday and Tuesday while shifting more so into north central
or central FL on Tuesday. We don`t see much appreciable change in
the moisture levels with PWATs of 1.8 to 2.2 inches and given the
weak synoptic flow, sea breezes and daytime heating should lead
to scattered to numerous shower and storm coverage each day, though
some slightly drier air across the eastern zones may limit convection
there. Max temps will be in the lower to mid 90s and with the dewpoints
of mid 70s, occasional upper 70s, some heat advisory criteria will
be possible in some locations each day. Lows mainly in the mid
70s are anticipated.

&&

.AVIATION...
(06Z TAFS)
Issued at 152 AM EDT Wed Jul 3 2024

Lower ceilings for coastal sites and potentially affecting inland
sites VQQ and GNV overnight and into the early morning hours with
convection building in the afternoon building at around 18z in
conjunction with the east coast sea breeze and then building
inland. Winds will build from out of the east in the afternoon and
then become more mild and variable Wednesday night.

&&

.MARINE...
Issued at 400 AM EDT Wed Jul 3 2024

Prevailing winds have shifted to easterly as high pressure building
over the Mid-Atlantic states wedges down the southeastern seaboard.
Showers and thunderstorms will increase in coverage across our
local waters along and south of a stalled frontal boundary today.
The frontal boundary will gradually dissipate over the Georgia
waters by Thursday, with prevailing onshore winds continuing as
high pressure weakens off the eastern seaboard. Coverage of
showers and thunderstorms are expected to decrease across our
local waters late this week through Saturday, with prevailing
winds then shifting to southwesterly during the weekend ahead of
the next weakening frontal boundary that will be entering the
southeastern states.

Rip Currents: Moderate Risk for beaches through Thursday given the
slight increase in local waves/seas at the nearshore buoys.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  92  74  93  74 /  70  30  30  10
SSI  90  79  90  78 /  60  20  30  10
JAX  93  76  92  75 /  70  30  70  20
SGJ  92  77  91  77 /  60  20  60  10
GNV  93  74  92  74 /  70  40  70  30
OCF  94  75  93  76 /  70  50  70  30

&&

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

$$