Damaging Wind and Lightning Strike in Florida, August 31, 2022

Area Forecast Discussion
National Weather Service Jacksonville FL
1015 AM EDT Wed Aug 31 2022

...New UPDATE...

.UPDATE...
Issued at 951 AM EDT Wed Aug 31 2022

It looks like there will be two sources of convergence today. One
near the I-95 corridor where the east coast sea breeze remains
pinned over the near shore waters this morning then meets up with
southwesterly flow and advecting convection this afternoon, where
best rainfall and areal coverage of thunderstorms is anticipated.

Another area of convergence this afternoon is somewhere near the
I-10 corridor to just north of FL/GA where some high resolution
models show WNW meeting associated with upstream surface trough
and outflow zipping up with with WSW sfc flow with developing west
to east convective line.

Storms that pulse will be capable of producing downburst winds of
40-50 mph, frequent lightning strikes, and locally heavy
downpours. Localized flooding will be possible, especially at
urban locations along the I-10 and I-95 corridors. Later
development of convection should allow highs to climb to the lower
90s at most locations, except upper 80s in the Suwannee Valley
and north central FL. Overnight lows will be in the low to mid
70s.

Current forecast trends looks good.

&&

.NEAR TERM...
(Today and tonight)
Issued at 340 AM EDT Wed Aug 31 2022

Patchy fog will be possible during the pre-dawn hours across
inland SE GA. Troughing digging from the Great Lakes into the mid-
Atlantic region will shift east-northeastward into New England as
a shortwave trough moves through the SE US and then cuts off near
the FL/GA border by tonight. This weather pattern will result in
decreasing support for the frontal boundary shifting southward
before stalling near central GA by tonight. West-southwesterly
flow will deepen locally ahead of this shortwave and approaching
frontal boundary, resulting in a more active afternoon and evening
of convection than yesterday. Convection should fire across SE GA
and also along a dominant Gulf coast sea breeze, with activity
expected to move east-northeastward. A few strong thunderstorms
will be possible along the I-10 and I-95 corridors as mesoscale
boundaries collide by late afternoon and early evening, especially
as activity merges with a pinned Atlantic sea breeze boundary
along the I-95 corridor. Storms that pulse will be capable of
producing downburst winds of 40-50 mph, frequent lightning
strikes, and locally heavy downpours. Localized flooding will be
possible, especially at urban locations along the I-10 and I-95
corridors. Later development of convection should allow highs to
climb to the lower 90s at most locations, except upper 80s in the
Suwannee Valley and north central FL. Overnight lows will be in
the low to mid 70s.

&&

.SHORT TERM...
(Thursday and Friday)
Issued at 340 AM EDT Wed Aug 31 2022

Thu & Thu night...A return to a stormier, wetter pattern as the
surface front stalls and lingers over the local area under a mid
level low and upper level trough that deepens across the FL peninsula
Thursday. Scattered showers and isolated storms are expected Thu
morning across portions of SE GA and the Suwannee River Valley
where a broad surface low is expected to form along the surface
trough axis under the deepening mid/upper level trough. High deep
layer moisture with PWAT 2.2-2.3" will coincide near the broad low
under weak 1000-700 mb steering flow < 5 kts and enhanced upper
level diffluence. These convective ingredients are quite favorable
for areas of training, heavy rainfall, especially across SE GA
and portions of the Suwannee River Valley. SE of the broad surface
low and surface trough axis, expect more of a diurnally enhanced
convective pattern into the afternoon and evening near the St.
Johns River basin where sea breezes and outflows converge. The
broad low begins to retrograde as mean layer high pressure
strengthens ENE of the region and the upper trough lifts out the
NE. Rainfall chances will tapper off for inland areas, but with
the lingering trough axis and developing ESE low level flow, a
chance of mainly coastal showers and isolated storms will continue
through Friday morning especially across coastal SE GA near the
linger trough axis.

Fri & Fri night...SSE steering flow develops into Friday afternoon
with the higher rain chances shifting inland with a continuation
of a localized flood threat generally near and north of the I-10
corridor where deeper moisture will linger. Friday night, precip
fades inland and shifts westward as ridging strengthens over the
area from the ENE. Onshore flow will maintain a low chance of
coastal showers or an isolated thunderstorm into Saturday morning.

High temperatures will trend near to below normal across SE GA and
near the I-10 corridor where more convective cloud cover, with a
range from the mid 80s to near 90. Southward across our north-
central FL zones, highs will near the low 90s before convection.
Low temperatures will range near to above normal in the 70s with
patchy inland fog potential.

&&

.LONG TERM...
(Saturday through Tuesday)
Issued at 340 AM EDT Wed Aug 31 2022

Prevailing easterly flow sets-up with surface high pressure NNE of
the region and coastal troughs forming over the adjacent coastal
waters shifting inland into the afternoon with diurnal heating.
Aloft, an upper ridge will build directly over the local area this
weekend through Tuesday. This regime will bring an earlier start
to convection to coastal areas with the higher afternoon/early
evening t'storm potential inland, generally west of Highway 301
toward I-75, but overall a tick-downward in rainfall coverage
compared to the past week as subsidence builds overhead. The main
hazard this period will be increasing rip current risk into the
holiday weekend given persistent easterly flow and building swells
with the tropical Atlantic becoming more active.

Temperatures will trend near normal from the mid/upper 80s coast
to low 90s well inland toward I-75 with lows in the 70s.

&&

.AVIATION...
(12Z TAFS)
Issued at 745 AM EDT Wed Aug 31 2022

Fog and low stratus will start to erode over KVQQ early this
morning with IFR VSBYs and CIGs dissipating. Scattered to
numerous showers and storms develop this afternoon with
PROB30/TEMPO groups for all sites. Southwesterly flow will keep
the Atlantic sea breeze pinned to the I-95 corridor with the sea
breeze merger near the I-95 occurring this late afternoon into
evening. Thunderstorm chances will linger through at least 01Z
for all TAF sites except GNV. Stratiform rainfall post convection
may linger until 04z. Cigs rise between 04z and 09z, with patchy
fog developing interior between 09z and 12z.

&&

.MARINE...
Issued at 340 AM EDT Wed Aug 31 2022

A frontal boundary over northern Georgia will slowly shift
southward into the southeast Georgia waters today into Thursday.
The front will then stall near the Florida and Georgia border by
Thursday night and Friday as high pressure builds over the Mid-
Atlantic states and New England. Scattered showers and thunderstorms
will develop over our local waters on Wednesday and Thursday,
mainly during the late afternoon and evening hours. High pressure
will then be located to the north northeast over the weekend into
early next week resulting in onshore flow.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  91  73  90  72 /  50  30  60  20
SSI  89  77  88  76 /  50  30  60  40
JAX  90  74  88  73 /  60  40  70  50
SGJ  89  75  88  74 /  60  30  60  50
GNV  89  73  88  71 /  60  30  70  40
OCF  89  73  90  73 /  60  20  60  30

&&

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