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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS62 KJAX 131910
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
310 PM EDT Thu May 13 2021

.NEAR TERM [Through Tonight]...

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An upper level trough over extends from the Great lakes to the
Big Bend with a surface cold front extending from the Gulf of
Mexico, across central Florida and into the Atlantic. The front is
proving to be the focusing mechanism for today`s rain with the
upper trough driving the rain shield eastward. Now with the
trough axis approaching the region the cloud shield is beginning
to be driven southward toward the central Florida peninsula. This
trend should continue overnight with the rain moving south and
offshore. Some light fog is possible in inland areas that saw
more significant rainfall today, but overall a drying trend
tonight.

.SHORT TERM [Friday Through Saturday Night]...

Eastern CONUS trough will shift off of the seaboard late Friday as
high pressure and drier air spill southward into the region this
weekend. As a result, west-northwesterly flow aloft will prevail
over the southeastern states. A gradual warming trend will occur
as heights rise aloft and low-level thicknesses increase. High
temps will be in the mid 70s coast to lower 80s well inland
Saturday, then upper 70s coast to mid 80s well inland on Sunday.
Sprawled surface ridge centered over the Ohio and Tennessee
Valleys will continue to wedge down the southeastern seaboard
through Saturday, keeping a tight pressure gradient in place.
Windy conditions will continue at coastal locations through
Saturday period, with prevailing wind speeds remaining in the
20-25 mph range with frequent gusts of 30-35 mph. Fair skies will
prevail inland. Winds will decouple after sunset at inland
locations on Friday and Saturday nights, allowing lows to fall to
the lower 50s throughout inland southeast GA and the northern
Suwannee Valley. Windy conditions at the coast will keep lows in
the low to mid 60s. The center of the expansive surface ridge will
shift off the Mid-Atlantic coast on Sunday, allowing low level
flow to veer easterly.

.LONG TERM [Sunday Through Thursday]...

Flow aloft will be zonal across the southeastern states through
Tuesday, with ridging aloft beginning to build over our area
towards midweek as closed troughing over the Desert Southwest
emerges over the Southern Plains. Breezy easterly winds will
continue at coastal locations throughout the period as surface
ridging strengthens near Bermuda, keeping a rather tight local
pressure gradient in place. Low level moisture may increase enough
for a priming of the lower atmosphere Tuesday with recovering
moisture levels with model blends indicating isolated to widely
scattered POPs Wednesday and Thursday. An isolated afternoon
thunderstorm cannot be ruled out along the inland-moving Atlantic
sea breeze by Wednesday afternoon.

Highs will climb to the mid to upper 80s along the I-75 corridor
on Monday and will continue to climb by a degree or two each day,
reaching the lower 90s by midweek. A fairly dry air mass will
remain in place through at least Monday, with lows moderating to
the low and mid 60s by midweek with some coastal areas having
minimums warming to near 70 towards midweek time-frame.
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&&

.AVIATION...
[Through 18Z Friday]

As rainfall continues to taper off across the region all CIGS have
lifted to IFR across the NE FL TAF sites and to MVFR at SSI. This
improving trend will slowly continue late this afternoon and
evening with VFR conds expected at SSI by 22Z, then around 00Z at
the JAX metro TAF sites, by 02Z at GNV, then the N-NE flow is
expected to hold onto some lower MVFR CIGS at SGJ until 04Z then
becoming VFR during the overnight hours. For now have continued to
leave any significant fog out of the inland TAF sites as there
should be drier airmass and just enough wind push south through
the region during the overnight hours. Mainly VFR conds are
expected for Friday in the 12-18Z period with increasing NE winds
at 12-16 knots gusts to 20-24 knots in the 14-18z time frame with
highest winds at the Atlc Coast.

&&

.MARINE...

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The pressure gradient between high pressure over the Great Lakes
States and Mid-Atlantic and lower pressure over The Bahamas will
maintain Small Craft Advisory conditions across our coastal
waters through Saturday morning. Winds will begin to relax on
Friday but seas will take some time to subside. As we move into
Saturday the ridge will be positioned a bit further south with
the strongest northeast flow more oriented toward south and
central Florida. Conditions will be significantly better on Sunday
and Monday with the high centered near Cape Hatteras-Virginia
Beach. The next cold front will move through on Wednesday with
Small Craft Advisory conditions returning to the waters.


Rip Currents: High rip current risk today through Friday as strong
northeast winds continue producing rough surf with breakers up to
6 feet.
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&&

.FIRE WEATHER...

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A drier air mass is beginning to filter into the northern areas and
will continue to drop south through Friday. On Friday and into
Saturday inland areas will see gusty northeasterly transport
winds which will generate significant dispersion values at inland
locations on both afternoons. Minimum relative humidity values
are still expected to drop to critical/near critical values on
Saturday afternoon across inland areas.
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&&

.PRELIMINARY POINT TEMPS/POPS...

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AMG  50  77  50  79  53 /   0   0   0   0   0
SSI  60  73  62  77  65 /   0  10   0   0   0
JAX  55  76  59  78  61 /   0  20   0   0   0
SGJ  61  76  64  77  65 /  10  20  10   0   0
GNV  54  81  55  81  57 /   0  10   0   0   0
OCF  57  83  59  84  60 /   0  10   0   0   0
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&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Friday evening for Coastal Duval-
     Coastal Flagler-Coastal Nassau-Coastal St. Johns.

GA...High Rip Current Risk through Friday evening for Coastal Camden-
     Coastal Glynn.

AM...Small Craft Advisory until 8 AM EDT Saturday for Coastal waters
     from Altamaha Sound to Fernandina Beach FL out 20 NM-
     Coastal waters from Fernandina Beach to St. Augustine FL
     out 20 NM-Coastal waters from St. Augustine to Flagler
     Beach FL out 20 NM-Waters from Altamaha Sound GA to
     Fernandina Beach FL from 20 to 60 NM-Waters from Fernandina
     Beach to St. Augustine FL from 20 to 60 NM-Waters from St.
     Augustine to Flagler Beach FL from 20 to 60 NM.

&&