519 
FXUS62 KJAX 021202
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
802 AM EDT Thu Sep 2 2021

.AVIATION...
[Through 12Z Friday]

Brief, local areas of MVFR ceilings expected around VQQ and 
potentially JAX, and CRG based on IR imagery and observations. 
Otherwise VFR for remainder terminals through 17Z. The air mass 
will remain moist over our FL counties for an afternoon round of 
seabreeze driven convection. Southwest to west winds 5-10 kt will
prevail as a weak cool front moves into southeast Georgia. With 
moist airmass in place, scattered to numerous thunderstorms are 
expected across northeast FL from 18Z to 00Z and mainly south of 
a line from Waycross to SSI from 18Z to 00Z. Heavy rain can 
briefly reduce visibilities and clouds to at least MVFR this 
afternoon. Showers and thunderstorms should decrease in areal 
coverage after 00Z with the loss of daytime heating but with the 
weak front in the area some lingering isolated convection is still
likely to happen and can be addressed in subsequent TAF forecasts.
The front is expected to push south of the TAFs near or after 06Z
Friday, with potential for low ceiling/vsby around VQQ and GNV 
toward 12Z Friday.

&&

.PREV DISCUSSION [307 AM EDT]...

.NEAR TERM [Through Tonight]...

A strong shortwave trough was diving southeastward across northern 
Georgia this morning, and this shortwave will move into the area 
this afternoon. At the surface, a frontal boundary was north of 
the area early this morning, and scattered showers and storms were
developing along it and pushing into interior southeast GA. A few
showers also moved across Coffee and Ware County in southeast 
Georgia. The frontal boundary will drift into southeast Georgia 
around daybreak this morning and stall around Waycross this 
afternoon. Another surface boundary was located across Marion 
County, and low stratus and patchy fog was located near this 
boundary. Scattered showers and embedded storms are forecast to 
develop along and south of this boundary before daybreak this 
morning. Both of these boundaries, and the east coast sea breeze 
will be focus areas for convection today. 

Showers and embedded storms will develop across north central FL 
this morning along a surface boundary. This boundary will drift
southward by the afternoon, and showers across this area are 
forecast to fade. The east coast sea breeze is forecast to develop 
early this afternoon, and numerous to widespread showers and 
storms will develop along the frontal boundary and the east coast
sea breeze. These showers and storms will be enhanced by the 
incoming upper level shortwave trough. Widespread rainfall amounts
across northeast Florida are expected to be in the 0.5-1 inch 
range. Locally heavy rainfall is possible for the Jacksonville 
metro area, including all of Duval, eastern Clay, and St. Johns
Counties, where widespread rainfall amounts of 1 inch are 
forecast, and locally heavier amounts of 2-4 inches are possible. 

The upper level trough axis and shortwave trough will shift into 
north central Florida in the early morning and then south of the
area by daybreak. Drier air will filter into southeast Georgia in
the evening, with precipitable water values falling to 1-1.5 
inches. Showers and storms will wind down across northeast Florida 
in the late evening hours, with mostly dry conditions after 
midnight as the cold front slides just south of I-10 by daybreak.

Highs today will be in the upper 80s to lower 90s. Overnight lows
will be 70-75F.


.SHORT TERM [Friday Through Saturday]...

The upper level trough axis will push south of the area Friday 
morning, but a cutoff upper low is forecast to develop over the 
regional Atlantic waters. Surface high pressure will build to the
north of the area, and northeasterly low level flow will develop.
Isolated showers are possible along coastal southeast Georgia, 
with scattered showers and storms mainly south of I-10 as drier 
air continues to push southward into the area. Precipitable water 
values are forecast to fall to 0.75-1 inch across southeast 
Georgia and the I-10 corridor by Saturday morning. This drier air 
is forecast to shift westward through the day as a coastal trough 
develops, and moisture slowly increases. 

Highs are forecast to be in the mid 80s to around 90 degrees.
Cooler overnight lows are expected Saturday and Sunday morning, 
with temperatures in the mid to upper 60s across interior 
southeast Georgia and the I-10 corridor, and the lower 70s 
elsewhere.


.LONG TERM [Sunday Through Thursday]...

Guidance differs on the placement of cutoff upper low and thus 
how much and how fast moisture will return to the region. For now,
kept the area mostly dry on Sunday, with scattered showers and
storms returning to the area each day next week. 

An upper trough will gradually dig south from the Great Lakes 
region during the first half of next week. In the return to 
northwest flow, a cold front will likely cross the Mid South 
region next Tuesday and make its way towards the area by the 
middle of the week. Southwest flow early next week will also mean 
a return of low-level moisture, with rain chances gradually 
increasing through the middle of the week.

Highs will be in the upper 80s to lower 90s each day, with lows in
the 70s.


.MARINE...

A frontal boundary will push into southeast Georgia this morning
and then to around the FL/GA border tonight, then stall across the
northeast Florida waters tonight. This trough will linger just to
the southeast Friday into Friday night, as high pressure builds 
to the north. The trough will sink further south over the weekend 
as high pressure builds across from the northeast. Another cold 
front will approach from the northwest early next week.

Rip Currents: Low risk of rip currents at the area beaches today
and Moderate Risk of rip currents at the northeast Florida and
southeast Georgia beaches on Friday.


.FIRE WEATHER...

A cold front will push into southeast Georgia today and then stall
across northeast Florida tonight. Drier air will move into
southeast Georgia this afternoon through the end of the week.
Locally heavy rainfall is possible across northeast Florida today,
with isolated 2-4 inch rainfall amounts possible.

&&

.PRELIMINARY POINT TEMPS/POPS...

AMG  89  69  89  65  89 /  50  10  10   0  10 
SSI  89  75  86  73  86 /  60  30  20  10  10 
JAX  91  72  88  69  88 /  80  50  30  10  20 
SGJ  90  74  87  74  86 /  80  50  40  20  30 
GNV  89  71  88  70  89 /  80  30  50  10  30 
OCF  89  72  89  72  91 /  80  50  60  10  40 

&&

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