843
FXUS62 KJAX 240038
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
838 PM EDT Sun Jun 23 2024

...HEAT INDEX VALUES APPROACH ADVISORY LEVELS AGAIN MONDAY AND
TUESDAY...

.UPDATE...
Issued at 830 PM EDT Sun Jun 23 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

Isolated convection at about 8 pm continues to diminish this evening
and will end all the precip in the forecast by about 10 pm, as
lingering instability continues around the SuwanNee Valley area
and where outflows converged. Localized rainfall amounts recently
around Live Oak were near 4 inches. Not much in terms of thunderstorm
wind gusts recorded at stations this afternoon and evening with
highest values around 35-40 mph. Rest of tonight, the low level
flow is primarily be southwest to south and will slowly veer
around by sunrise. Partly cloudy skies will decrease in coverage,
though there may be a small area of low stratus over the Suwannee
Valley area late tonight and early Monday morning. Could see a few
showers or a storm develop late tonight toward Marion county.
Warm overnight lows expected in the lower to mid 70s given the
moist low levels and winds of about 5-10 mph. Some stronger
southerly winds anticipated at least for first part of tonight
along the coast at 10-15 mph at times.

Little change for Monday`s forecast with scattered showers and
storms in the aftn. Best chances expected over northeast FL. Highs
in the mid to upper 90s are indicated. Heat indices will be near
advisory levels Monday across northeast FL.

Climate-wise, we tied the record high at JAX today, and we may
see record warm minimum temps next 24 hours. On Monday, record
high possible at Craig Airport, with current record at 98 deg from
2019.

For the marine forecast, little overall change rest of tonight
with small craft exercise caution headline in effect. Only slight
wind and sea changes anticipated for this update.

&&

.NEAR TERM...
Issued at 311 PM EDT Sun Jun 23 2024

Troughing stretching across the eastern US will maintain west-
northwest flow across the area today. Outflow boundary from
morning convection across north-central FL continues to lift
northward and collide with the inland moving sea breezes this
afternoon developing scattered convection. Mid-level dry air has
filtered in from the northwest lowering dewpoints into the low-mid
60s across inland SE GA and Suwannee Valley. Storms may be strong
as they develop along boundary collisions in NE FL with the mid-
level dry air increasing DCAPE values. Sea breezes will likely
collide near the U.S. Highway 17 corridor late this afternoon,
with activity likely migrating towards the I-95 corridor towards
sunset. Convection subsides by midnight. Early morning showers
developing in the Nature Coast may move into Marion and Gilchrist
counties in the pre-dawn hours. Overnight lows be in the 70s.

&&

.SHORT TERM...
(Monday through Tuesday night)
Issued at 311 PM EDT Sun Jun 23 2024

A weakening frontal boundary approaches the area on Monday, with a
south to southwesterly flow persisting out ahead of if it as the
Bermuda high will be centered almost due east of the First Coast.
The flow should be strong enough to keep the sea breeze pinned in
the vicinity of I-95 and towards the coastline. The focus for sea
breeze convection will be generally along this area, although the
presence of the diffuse boundary as well as perhaps some outflow
from earlier convection from the northwest could also play factor,
and therefore possibly a source of "secondary" chances over more
inland southeast GA.

The aforementioned boundary essentially stalls and weakens/becomes
diffuse just north of southeast GA counties Monday Night and into
Tuesday. Guidance is suggesting some lingering drier air bleeding
into areas generally from about Waycross northward tomorrow, with
PWATs in the 1.2 to 1.5 inch range (below climo). Therefore,
convective chances look to be lower in these areas and mainly
focused approaching I-10 and southward.

The southwesterly flow regime will result in temperatures above average
for both Monday and Tuesday: in the mid to upper 90s, almost all
the way to the immediate coastline. The majority of the area is
expected to remain just below heat advisory criteria, though some
spots could see heat indices flirting with that threshold at
times, especially around the St. Johns River to the coast and
Suwannee Valley.

&&

.LONG TERM...
(Wednesday through Saturday)
Issued at 311 PM EDT Sun Jun 23 2024

The pattern remains pretty stagnant into Wednesday with south to
southwest flow and diurnal convection along the sea breeze
collision area inland. Another frontal boundary approaches
Thursday and similarly stalls out and becomes diffuse to our
north, though will bring increased layer moisture ahead of it
which should essentially last into Friday and the start of the
weekend. High pressure behind the front will start to build more
to our northeast by Friday and into the weekend, which should
return more of a weaker flow out of the east to southeast and
therefore a pretty typical summer sea breeze type of pattern.
Temps start above average for this period, but gradually trend
more towards normal as the synoptic flow becomes more broad and
weaker compared to earlier in the week.

&&

.AVIATION...
(00Z TAFS)
Issued at 830 PM EDT Sun Jun 23 2024

VFR clouds expected to prevail overnight, though some low stratus
could form and move toward GNV and VQQ between 06z-13z Monday.
Confidence remains on the low side on this potential. Sct cumulus
expected to form about about 13z-16z Monday. A near repeat of
scattered showers and storms on Monday aftn and evening, mainly
during the aftn. Have introduced VCTS by about 18-20z, with no
more than a PROB30 group shown after 19z. Sfc winds tonight will
be southerly near 5-10 kt and diminish slightly toward early
morning. West to southwest winds expected Monday morning, then
back more southwest and south. The south winds will mainly be for
the coastal TAFs as a weak Atlantic sea breeze develops.

&&

.MARINE...
Issued at 311 PM EDT Sun Jun 23 2024

South-southeasterly winds develop this afternoon over the near
shore waters as the Atlantic sea breeze moves inland. Winds will
shift to south- southwesterly and will surge to Caution levels
throughout our local waters this evening outside of ongoing
thunderstorm activity. West-southwesterly winds will prevail for
the rest of the week as another trough settles over the
southeastern states, with scattered thunderstorm chances
prevailing each afternoon and evening as activity moves eastward
across our local waters.

Rip Currents: Developing onshore winds this afternoon will combine
with an easterly ocean swell to create a moderate rip current risk
at all area beaches. The easterly swell will begin to fade on
Monday, dropping the risk to low for the southeast GA beaches,
while onshore winds during the afternoon keep a lower end moderate
risk at the northeast FL beaches.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  75  96  75  98 /  10  30  20  40
SSI  78  95  79  93 /  20  30  30  30
JAX  75  97  75  96 /  20  40  30  50
SGJ  76  96  77  94 /  20  50  30  50
GNV  74  95  74  95 /  30  60  20  70
OCF  74  94  75  94 /  40  70  20  70

&&

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

$$