Area Forecast Discussion
Issued by NWS Jacksonville, FL
FXUS62 KJAX 300725
Area Forecast Discussion
National Weather Service Jacksonville FL
325 AM EDT Thu Mar 30 2017
...MARGINAL RISK OF SEVERE STORMS FRI MORNING...
.NEAR TERM...Today through Friday...
Increasing rain chances over the next couple of days as
persistent ridging breaks down over the southeast as a long wave
trough currently across the great plains edges eastward. Today a
few early morning showers will continue to impact parts of SE GA
along and north of a lifting warm front. Morning fog signals are
not very strong with a progressive increase in high clouds ahead
of the approaching frontal system and lingering debris clouds from
some convection across SE GA. At this time advertised patchy fog
By midday a few showers will begin to pop along the sea breezes
with a better chance of airmass showers popping across inland SE
GA. Continued to focus the highest chances of showers and isolated
tstorms generally along and east of the Highway 301 corridor
across SE GA decreasing southward over NE FL where moisture will
be more limited. Increasing SW steering flow will push afternoon
convection offshore of the coast this evening. Given cooling 500
mb temps of -13 to -14 deg C across SE GA later this afternoon and
early this evening a rogue stronger storm could produce some hail
and/or gusty winds.
Tonight evening precipitation will push offshore of the Atlantic
coast...while pre-frontal precip edges toward our western GA zones
after midnight. Models diverge with the timing and coverage of
pre-frontal rainfall across the area late tonight through
Friday...with the MET and ECMWF generally drier compared to the
GFS for most sites across the forecast area. Despite the
discrepancy of precip intensity and coverage...guidance does
concur with the greatest chances of rainfall across SE GA Fri
morning...then a decrease in rainfall across the area into the
afternoon as the precip pushes across the forecast area as a
strong mid/upper level dry slot wraps across the area. This dry
air intrusion is expected to tapper off rainfall as it moves
across the region through midday Fri with just a few sparse
showers possible by Friday afternoon across our southern Florida
zones. Still looks to be a chance of a few strong thunderstorms
early Friday morning across SE GA and the Suwannee River Valley
where cold 500 mb of -15 to -16 deg C will traverse the area with
a modest low level jet of 30-35 kts from the SW. Severe storm
potential decreases from the WNW into the afternoon as drier air
overrides the area and dynamics lift NNE of the region.
Above normal temperatures will continue this period with near
record high temperatures again today across portions of SE
.SHORT TERM...Friday night through Saturday night...A dry cold front
will move across the area Friday night. Ridging at surface and aloft
will produce a fair and dry weather pattern with light winds through
Saturday night. Temperatures will be above normal with lows mostly
in the 50s and highs in the 80s.
.LONG TERM...Sunday through Wednesday...Upper ridge axis will be
situated across the se on Sunday providing warm and dry conditions.
High temperatures will range from the lower 80s coast to the mid to
upper 80s inland. An upper low will move from the southern Plains to
the se coast Monday and Monday night. At the surface a low pressure
center will move by to the north which will bring a pre-frontal
trough across se Ga/ne Fl on Monday. This boundary may produce
strong to severe storms Monday into Monday night as instability and
vertical wind shear increase. Some model differences in timing exist
with the GFS a little faster than the ECMWF. A cold front with drier
air will move through on Tuesday. Temperatures will remain above
average through the period.
.AVIATION...Prevailing VFR conditions advertised for all terminals
less VQQ where some patchy ground fog is possible based on climo.
Scattered mid level clouds and increasing cirrus expected to
prevent significant fog formation this morning. Best chances of
showers today will be near SSI where VCSH was advertised as well
as at JAX/CRG after 21Z as precip drifts toward the Atlantic coast
through the evening. SSE flow will veer SSW overnight tonight
ahead of approaching cold front.
.MARINE...SE winds today with seas 4 ft or less. Winds will
increase late this afternoon into the evening from the SSW ahead
of an approaching cold front to 15-20 kts and seas building to 5-6
ft over the outer waters. Winds expected to remain just shy of
advisory criteria Fri with the frontal passage...then offshore
flow Friday night trailing the front. High pressure settles over
the region this weekend with lighter sea breeze dominated flow
expected. A much stronger frontal system approaches Mon with
southerly winds increasing to advisory levels ahead of the system.
Elevated offshore flow continues into Tue trailing the
front...then a decrease in magnitudes into Tue night as high
pressure tries to rebuild northward over south Florida.
Rip Currents: Moderate risk today due to persistent ESE swells
near 2 ft and periods of 10-11 seconds. Low risk of rips Fri under
.Climate...Record max temperature for Alma was reached yesterday.
The new record is 87 which broke the old record of 86 set in
1998. Another day of near record highs for SE GA is expected
.PRELIMINARY POINT TEMPS/POPS...
AMG 84 64 83 56 / 40 40 40 10
SSI 78 65 84 62 / 40 50 20 10
JAX 86 63 86 58 / 40 40 20 0
SGJ 84 65 84 60 / 30 30 30 0
GNV 87 62 84 55 / 20 10 30 0
OCF 85 63 83 57 / 20 10 30 10