445
FXUS62 KJAX 202335
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
735 PM EDT Sat Jul 20 2024

...New AVIATION...

.NEAR TERM...
Issued at 200 PM EDT Sat Jul 20 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

Broad 500 mb troughing extends over the Great Lakes southward to
the lower MS Valley. Some weak mid level vort lobes are forecast
to move across AL and parts of GA ahead of the trough in southwest
flow aloft. Plenty of moisture exists with regional analyses
showing PWATS of 1.9 to 2.1 inches. Max temps continue as forecast
in the lower 90s, with heat indices generally near 108 or less,
just below advisory. Showers and storms should become more numerous
and possibly widespread during the peak time frame from 4 PM-8 PM
and then translate offshore into coastal waters. Main threats
will be strong wind gusts and frequent lightning. SPC continues to
highlight a marginal risk of severe storms mainly across
southeast GA through the evening, mainly for a locally damaging
wind gust. Some lingering showers and isolated to scattered
tstorms likely around from 9pm to midnight before nearly
dissipating by 1 am. Some light patchy fog possible but not
expected to be mentioned in the forecast text. Lows tonight in the
71 to 76 deg range.

&&

.SHORT TERM...
(Sunday through Monday night)
Issued at 200 PM EDT Sat Jul 20 2024

High pressure will be located east northeast of the region through
this period. The location of the high is significant, as the flow
around it will help to dictate the direction storms moves. This past
week, the high has been located to the east, with weak troughing to
the northwest. This pattern produced a southwest flow, and pushed
convection toward the east coast each afternoon, with the east coast
sea breeze largely stuck near the coast.

However, with the high to the east northeast, the prevailing flow
will be from the south southeast this period. Convection this
period, with initiate in the early afternoon hours of Sunday and
Monday once diurnal heating provides enough instability. This
convection will then be aided, and pushed inland by both the east
coast sea breeze and to a lesser extent by the Gulf sea breeze.

The sea breezes will then meet toward the center of the forecast
area Sunday, where the greatest chance for mid to late afternoon
convection will occur. On Monday afternoon, the east coast sea
breeze will push a little further inland due to the high being a
little further to the northeast, yielding a more southeast flow
overall. Therefore, the sea breeze merger should take place closer
to the I75 corridor, where the greatest potential for convection
will exist in the mid to late afternoon hours. While, a few storms
can not be ruled out near the east coast, the chance will be much
lower this period, than this past week.

The convective activity will diminish during the evening hours each
day, with dry nights forecast.

Temperatures will trend a little above normal this period.

&&

.LONG TERM...
(Tuesday through next Saturday)
Issued at 200 PM EDT Sat Jul 20 2024

The high will remain centered to the east northeast through at least
Thursday night, continuing the flow from the south southeast. This
will continue the convective routine, with storms bubbling up in the
early afternoon across the area, then being directed inland by the
sea breezes. The east coast sea breeze will again be dominant due to
help from the south southeast flow pattern. The breezes will merge
near the I75 corridor, where the convective maximum will occur each
afternoon. With loss of heating, convection will diminish during the
evening hours, with dry nights forecast.

Models are hinting at a pattern shift late in this period, as a
trough digs into the southeastern US, pushing the high back toward
the east again. If this pattern sets up, the area will be back in a
more southwest flow, with convection moving east northeast through
the day, and merger occurring closer to the east coast, with I95
corridor receiving the convective max later in the afternoon hours.

Temperatures will trend near to a little above normal this period.

&&

.AVIATION...
(00Z TAFS)
Issued at 723 PM EDT Sat Jul 20 2024

Mainly VFR conditions overnight as gusty showers and storms move
offshore by about 02z with potential for reduced visibilities for
VQQ in the early morning hours. Convection will redevelop on
Sunday by around 18-20z building from west to east, first over GNV
and then forming eastward towards the coast.

&&

.MARINE...
Issued at 200 PM EDT Sat Jul 20 2024

Southeast to south winds around 10-15 kt expected into the
evening and then shift more southwest by sunrise. A similar
situation on Sunday into Monday. Seas mainly 2-3 ft. Early next
week, the surface ridge will begin to shift a bit more northward,
allowing more south to southeast flow to prevail and result in
general sea conditions to nudge up from combo of wind waves and
an east- southeast wind sea. May also see some surges in southerly
winds up to near 15-20 kt for brief times (about 5 pm-10 pm) through
the entire period, but models are not in good agreement on this
and duration of this not likely to warrant headlines at this time.
The main concern for boaters will be offshore moving t-storms the
next couple of days, peaking in the aftn and evening hours.

Rip Currents: A low-end moderate rip current risk owing to a mix
of wind waves and swells of about 8-10 second periods from the
east. This is likely to continue on Sunday as well.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  73  91  73  93 /  50  60  40  70
SSI  77  88  78  90 /  70  40  50  50
JAX  75  93  75  94 /  50  70  30  60
SGJ  75  92  75  93 /  60  40  20  50
GNV  73  93  73  93 /  40  60  20  70
OCF  74  94  75  94 /  40  60  20  90

&&

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

$$