Heavy Rain in Georgia, December 1 to 2, 2023

Area Forecast Discussion
National Weather Service Jacksonville FL
743 PM EST Thu Nov 30 2023

...New UPDATE...

.UPDATE...
Issued at 732 PM EST Thu Nov 30 2023

For the latest NE FL and SE GA Daily Key Messages please visit:
https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

Forecast remains on track as mid/high clouds continue to stream
aloft out of the Gulf of Mexico and across the region with local
radars showing some weak echoes (likely mid level Virga) but
enough dry air below 500 mb to have most of any moisture aloft
evaporate before reaching the ground and measurable rainfall
chances remain at 10% or less tonight. Closer to the surface, the
boundary layer flow has shifted to the south and is advecting a
bit more moisture just overtop of the surface flow from the East
and Northeast and this has already cooled surface temps back down
into the 50s in most locations, with lows expected in the upper
40s across SE GA and lower/middle 50s across NE FL. Winds will
remain light through the night and if enough breaks in the clouds
occur towards sunrise, there might be enough cooling to support
some patchy fog (mainly 3-5 mile vsbys) and significant dense fog
is not expected at this time. On Friday, quasi warm frontal
boundary will lift north of the region and SW steering flow ahead
of the approaching system will push temps back above normal as
skies become partly sunny. Highs should reach into the upper 70s
across inland SE GA and around 80F/lower 80s across inland NE FL,
while surface flow from the SE will keep the Atlantic beaches in
the 70s for afternoon highs. A few light pre-frontal showers will
be possible, mainly across inland SE GA and the Suwannee Valley of
inland NE FL, but overall rainfall chances remain around 20% or
less, although showers will remain possible over the Atlantic
Coastal waters late tonight through Friday.

&&

.NEAR TERM...
(through Tonight)
Issued at 227 PM EST Thu Nov 30 2023

For the latest NE FL and SE GA Daily Key Messages please visit:
https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

High pressure will continue to move away to the northeast through
Tonight, with lingering inverted trough over the coastal waters. The
region is in the east side of a large and fairly flat 500 mb trough,
which will allow upper energy to move across area producing high
cloudiness. It is expected to be a mainly dry night, but a few light
showers will be possible over north central and coastal FL due to
inverted trough.

With the flow onshore, it will be a much milder night, with lows
ranging from the upper 40s well inland SE GA, to the lower 60s
coastal NE FL.

&&

.SHORT TERM...
(Friday through Sunday)
Issued at 227 PM EST Thu Nov 30 2023

This will be an active weather period.

The surface high will move away to the east northeast Friday, as a
cold front approaches from the northwest. A warm front is expected
to develop on the approaching frontal system, and extend east across
the area near the GA/FL line Friday afternoon. Lift associated with
this warm front will result in a few showers well inland in the
afternoon. The upper trough will become more amplified on Friday,
with upper clouds continuing to stream across. So, in general,
Friday will be a cloudy day. Temperatures will rise well above
normal with readings reaching the mid to upper 70s SE GA, and
upper 70s to lower 80s NE FL.

The warm front will move northeast across SE GA through the night
Friday night, with showers developing along it. While a few
showers will be possible across NE FL, the best chances will be
north of the front over SE GA. Lows in the lower to mid 60s will
be common.

The Saturday forecast is somewhat tricky, with warm front to the
north and cold front reaching western counties late in the day. Much
of NE FL could be rain free, while there will be significantly
higher rain chances expected for interior SE GA along with
thunderstorm potential. The temperature forecast will be very
dependent on rainfall coverage. Areas that are more rain free could
surge through the 80s in the afternoon given strength of warm
advection.

The cold front will remain largely to the northwest of the area
Saturday night, then sweep southeast across area Sunday. Rain will
overspread the area during this period. Temperatures will remain
well above normal through Sunday, but Sunday will be cooler than
Saturday.

The best chance for stronger storms this period will be far inland
counties Saturday evening.

&&

.LONG TERM...
(Sunday night through next Thursday)
Issued at 227 PM EST Thu Nov 30 2023

The cold front will move well to the southeast Sunday night, with
high pressure building overhead on Monday into Monday night.
Lingering showers expected for Sunday night.

Another cold front is forecast to move southeast across the area
Tuesday night into Wednesday. This boundary will pass through dry,
but will bring a reinforcement to the cooler airmass.

Temperatures this period, will be just below normal through Tuesday,
then trend even cooler.

&&

.AVIATION...
(00Z TAFS)
Issued at 619 PM EST Thu Nov 30 2023

VFR conds this evening with a mix of mid/high clouds, but the more
moisture rich boundary layer flow from the south overrunning the
cool airmass along with a few breaks in the sky cover towards
sunrise will likely support some 4-6SM fog at all TAF sites along
with the usual chances for IFR conds at VQQ in the 09-13Z time
frame. Mild southerly flow will mix out and low level BR in the
morning hours with winds increasing to 8-10G12-15 knots by the
afternoon hours along with some SCT low level Cu in the 2500-4000
ft range with SCT/BKN mid and high clouds aloft, but any rainfall
chances likely hold off until after the current TAF period on
Friday Night.

&&

.MARINE...
Issued at 227 PM EST Thu Nov 30 2023

High pressure will be northeast of the region through Friday
night, with weak troughing over the coastal waters. The high will
move further away to the northeast Saturday, allowing a cold front
to approach from the northwest. This front will move over the area
and stall Saturday night through Sunday. The front will push to
the southeast of the region Monday, with high pressure building
over area Tuesday.

Rip Currents: SE GA Low through Friday
              NE FL Moderate Today, Low Friday

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  47  78  61  76 /  10  20  60  70
SSI  56  73  62  75 /  10  10  30  50
JAX  53  80  63  79 /  10  10  30  40
SGJ  58  79  64  79 /  10  10  20  20
GNV  54  82  63  81 /  10  10  20  30
OCF  55  83  64  82 /  10  10  10  20

&&

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