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000
FXUS62 KJAX 210133
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
933 PM EDT Tue Apr 20 2021

.UPDATE...

Low level convergence along a pre-frontal trough axis spawned a
broken cluster of showers across interior SE GA this evening
enhanced by a mid level impulse aloft. Expect for this convection
to shift eastward toward the SE GA coast through midnight with
convection gradually fading in coverage and intensity as the
upper level support presses farther downstream.

There is also a low chance of showers across NE FL as a broad
surface low offshore of the central FL Atlantic coast tracks
farther offshore, with a wake trough meandering near our southern
FL zones under the passing, weak upper level impulse 03z through
09z.

Low stratus could edge inland from the GOMEX tonight near this
wake trough as well, affecting areas generally along and south of
a Gainesville to Palatka line. With the slow moving boundaries
across & near the local area this evening and saturated soils
especially across parts of NE FL, intermittent patchy fog is
likely at times until a drier offshore flow develops trailing the
pre-frontal trough axis through sunrise.

Temperatures were on track to cool to near seasonal lows in the
mid to upper 50s inland to low 60s toward the Atlantic coast.


&&

.MARINE...

SSE winds near 10 kts will veer SSW through midnight then to the
WNW through sunrise trailing the pre-frontal trough axis, with a
low chance of showers over mainly the SE GA coastal waters
tonight. Winds will increase over the outer waters trailing the
trough passage to 10-15 kts. Combined seas will continue in the 3
ft range or less. A dry cold front (no rainfall expected) will
push across the waters Wednesday afternoon/evening, trailed by
Small Craft Advisory conditions Wed night into Thu over the outer
waters.

Rip Currents: Moderate Rip Current Risk for NE FL beaches
Wednesday.

&&

.HYDROLOGY...

Portions of the Santa Fe basin including near Oleno State Park and
Worthington Springs were in Action Stage and are expected to crest
just below Minor Flood Stage Wednesday night or early Thursday.

&&

.PREV DISCUSSION [743 PM EDT]...

.NEAR TERM [Tonight through Wednesday]...
Weak wave along the front to the south has moved into the
Atlantic with rain shifting southeast of our area. A brief shower
may occur this evening over se Ga due to convergence near a
surface trough. Clouds will decrease overnight as the flow aloft
becomes wnw. This may result in patchy areas of fog by morning
mainly over ne Fl. Wednesday will be mostly sunny...breezy and
warmer as a dry cold front moves across the area. Temperatures
should reach the lower 80s area wide including the beaches due to
gusty offshore winds.


.SHORT TERM [Wednesday night through Friday Night]...
Cold front will push se of the area by Wednesday evening as high
pressure builds into the area from the northwest. Clear and cooler
conditions expected as temperatures drop into the 40s over inland
area with low/mid 50s near the coast. Thursday will be mostly
sunny with less wind and low humidity. Winds will veer to the NE
which will keep the beaches cooler. Highs will reach the upper 60s
coast to low/mid 70s inland. Thursday night will be another cool
night with a warming trend starting Friday as highs reach the
upper 70s and low 80s under increasing cloudiness. A chance of
rain is possible over se Ga Friday night as a warm front lifts
north from the Gulf ahead of the next upper trough.


.LONG TERM [Saturday Through Tuesday]...Vigorous upper shortwave
trough will move quickly east across the southern U.S. states
through the weekend. A warm front will lift north into central
Georgia on Saturday with ne Fl/se Ga in the warm sector as a
surface low tracks ne across the Tn Valley region. Best chance for
strong to possibly severe storms for our area appear to be
Saturday afternoon and evening as the approach of trough and max
instability combine with strong shear. Cold front will push
through the region Saturday night with rain ending by early Sunday
morning with clearing conditions. Surface high pressure will
build into the area with a dry nw flow aloft over the area
providing quiet weather with seasonal temperatures early next
week.


.AVIATION...
[Through 00Z Thursday]

VFR conditions expected early this evening across the terminals
under passing low & mid clouds (bases 4-6 kft and 8-12 kft) ahead
of an approaching pre-frontal trough edging south across GA. A
few light showers/sprinkles and ceiling restrictions are possible
as this trough axis settles across the terminals tonight, with
the highest probabilities of MVFR to IFR restrictions at GNV and
SGJ as westerly flow advects low stratus from the GOMEX inland
after 03z. ESE winds this evening less than 10 kts transition to
SSW to W through through 12z Wed with progressive ceiling improvement
from NW to SE as drier air funnels across the area with VFR for
all terminals by 12z. Breezy W-NW winds will increase midday with
gusts 15-20 kts as the actual surface cold front approaches.


.FIRE WEATHER...Breezy westerly winds with increased temperatures
and mixing heights will result in high dispersions across the
area on Wednesday. Drier air advecting into the area will lower
RH values into the 30 to 35 percent range during the afternoon.
Minimum RH values will be critical Thursday afternoon but with
lighter winds. Fuel moisture values continue to be high due to
recent rainfall especially over NE Fl.

&&

.PRELIMINARY POINT TEMPS/POPS...

AMG  56  79  40  71  43 /  30   0   0   0   0
SSI  61  82  49  68  53 /  20   0   0   0   0
JAX  59  83  48  70  51 /  20   0   0   0   0
SGJ  62  82  53  68  55 /  20   0   0   0   0
GNV  58  81  46  74  48 /  20   0   0   0   0
OCF  60  83  49  77  52 /  20   0   0   0   0

&&

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