708
FXUS62 KJAX 210648
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
248 AM EDT Sun Jul 21 2024

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

.NEAR TERM...
(Today and Tonight)
Issued at 244 AM EDT Sun Jul 21 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

Very subtle change in the pattern today with models trying to
inject some slightly drier airmass aloft around the high pressure
ridge axis from the south, but doubt this slight tweak will make
much of a difference as the SW steering flow pattern at the lower
levels and PWATs still close to 2 inches will still lead to
numerous to widespread showers and storms during the afternoon and
evening hours. There will be a slight shift in axis of highest
rainfall chances/storm activity towards inland areas as the East
Coast sea breeze front will make it further inland to the US 301
corridor and meet the Gulf Coast sea breeze front with mergers
creating some strong to isolated severe storm potential with gusty
downburst winds possible, along with a slightly slower storm
motion to produce heavy rainfall/localized flooding and of course
frequent lightning. The SW flow aloft will also likely push this
deeper thunderstorm activity back towards the Atlantic Coastal
counties towards the evening hours, but likely more in a weakening
capacity towards sunset, with most activity ending towards
midnight. Timing of the onset of convection will determine
eventual daytime Max temps, but overall expect widespread lower to
middle 90s inland and around 90F at the Atlantic beaches and these
combined with dewpoints into the middle 70s should push heat
indices into the 104-108F range, likely just below or just briefly
reaching Heat Advisory levels at this time. Overnight lows in the
lower to middle 70s over inland areas and upper 70s at the
Atlantic beaches.

&&

.SHORT TERM...
(Monday through Tuesday night)
Issued at 244 AM EDT Sun Jul 21 2024

High pressure towards the northeast will lead to southeasterly
flow over the area, which will help the Atlantic sea breeze make
its way well inland during the first half of the upcoming work
week. Daytime heating will get earlier convective activity going
along the sea breezes as they move inland. With the southeast flow
hindering the Gulf breeze`s inland progress, the merger of the
sea breezes will likely occur near the I-75 corridor, bringing
PoPs in the upper 70% from US-301 towards the I-75 corridor during
the afternoon to early evening hours. Temperature highs will
continue to sit in the lower 90s, with overnight lows in the lower
70s.

&&

.LONG TERM...
(Wednesday through Saturday)
Issued at 244 AM EDT Sun Jul 21 2024

The high pressure to the northeast will continue the pattern of a
far westward traveling Atlantic sea breeze, allowing for showers
and storms to develop along the Atlantic sea breeze as it moves to
the west. The I-75 corridor will continue to likely be the area
of most convective activity as the sea breezes merge over the
western portion of the area. Activity will diminish each evening
as the daytime heating is loss. Temperatures will trend near to
above normal with highs in the low-mid 90s and lows in the 70s.

&&

.AVIATION...
(06Z TAFS)
Issued at 109 AM EDT Sun Jul 21 2024

Rainfall has ended at all TAF sites and mainly expect just
leftover mid/high clouds through the overnight hours, possibly
some lower IFR/LIFR conds at VQQ towards sunrise, with some
chances for MVFR fog at other TAF sites around sunrise but
confidence not high enough to include at this time. Slightly lower
rainfall chances at TAF sites in a similar flow pattern this
afternoon and evening, but still higher than 60% at all TAF sites
so will add TEMPO groups in the 19-23Z range at GNV and 20-24Z
range at the other TAF sites for MVFR conds in TSRA once again.
Conds expected to improve to VFR after 02Z as rainfall chances end
once again towards the end of the TAF period.

&&

.MARINE...
Issued at 244 AM EDT Sun Jul 21 2024

Still no headlines expected over the next 5 days as high pressure
ridge from the Western Atlantic across the local waters will
weaken early this week and drift slightly north of the local
waters by mid week. Southerly flow today will slowly become more
Southeasterly through the upcoming week, mainly at 10-15 knots
with seas 2-4 feet. Main impacts will be offshore moving storms
during the afternoon and evening hours with strong/gusty winds to
30-40 knots, heavy rainfall and dangerous lightning.

Rip Currents: Low to moderate risk of rip currents will continue
through Monday as mainly southerly flow becomes onshore
Southeasterly during the afternoon hours at the local beaches with
surf/breakers of 2-3 ft.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  91  72  93  73 /  70  60  60  30
SSI  88  77  91  78 /  60  40  60  30
JAX  93  74  93  75 /  80  50  70  20
SGJ  91  75  92  76 /  60  50  50  20
GNV  94  73  94  73 /  80  60  80  20
OCF  94  73  93  75 /  80  50  80  20

&&

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

$$