687
FXUS62 KJAX 070821
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
421 AM EDT Fri Jun 7 2024

...NEAR RECORD HEAT CONTINUES THROUGH MONDAY...
...SCATTERED THUNDERSTORMS POSSIBLE ALONG THE I-95 CORRIDOR LATE
THIS AFTERNOON...
...INCREASINGLY DANGEROUS FIRE WEATHER CONDITIONS AS TEMPERATURES
SOAR...

For the latest NE FL and SE GA Daily Key Messages please visit:
https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

.SYNOPSIS...
Issued at 421 AM EDT Fri Jun 7 2024

Early morning surface analysis depicts a weak cold front pushing
southward into the southeastern states. Aloft...troughing was
digging southeastward from the Great Lakes region towards the
southeastern seaboard, while ridging was centered over west Texas
and the Desert Southwest. Latest GOES-East Total Precipitable
Water Imagery indicates that a much drier air mass was filtering
into the Deep South along and behind the approaching frontal
boundary, with PWAT values falling below 1.25 inches for locations
from Macon northward in central GA. Meanwhile, a ribbon of
slightly deeper moisture located ahead of the upper
trough/frontal boundary was advecting into our region, with PWATs
mostly in the 1.5 - 1.75 inch range. Mostly mid and high altitude
cloudiness was progressing eastward across our region, with
isolated convection developing ahead of the approaching frontal
boundary and digging trough for locations in coastal GA just to
the north of the Altamaha River. Otherwise, a light west-
southwesterly breeze around 5 mph prevails inland, with speeds
around 10 mph at coastal locations as of 08Z. Temperatures ranged
from the lower 70s for most of inland southeast GA to the lower
80s for coastal communities in northeast FL. Dewpoints were
generally in the upper 60s to lower 70s.

&&

.NEAR TERM...
(Today and Tonight)
Issued at 421 AM EDT Fri Jun 7 2024

Upper troughing will continue to dig into the southeastern states,
pushing the aforementioned frontal boundary across southeast GA
this evening, with this boundary then stalling and dissipating
near the FL/GA border later tonight and Saturday. A few showers
may develop this morning across inland southeast GA ahead of this
front, but the drier air mass along and behind the frontal
boundary will filter into inland southeast GA this afternoon,
likely keeping convective activity confined to northeast and
north central FL, with lower chances extending northward along the
southeast GA coast this afternoon. The narrow ribbon of deeper
moisture should trigger isolated to widely scattered convection
along the inland moving Gulf coast sea breeze during the early to
mid-afternoon hours, with activity potentially increasing in
coverage and possibly intensity as the Gulf and Atlantic sea
breezes collide between the U.S. Highway 301 and I-95 corridors
during the late afternoon hours, with mesoscale boundary
interactions potentially keeping convection going for an hour or
so past sunset for locations south of I-10.

Model soundings indicate weak lapse rates and slightly warmer
temperatures aloft this afternoon, but an isolated stronger storm
could pulse where mesoscale boundaries collide, with the primary
threats being lightning strikes, briefly gusty winds up to 40 mph,
and briefly heavy downpours. Breezy westerly winds in the
boundary layer will again bring hot temperatures all the way to
coastal locations, with near daily record highs possible at a few
locations today (see Climate section below for details). High
temperatures will soar to the mid and upper 90s nearly area-wide,
with maximum heat index values of 101-107 across coastal southeast
GA, northeast and north central FL, while the drier air mass
advecting into inland southeast GA this afternoon keeps values
around or just below 100 this afternoon.

Evening convection will then decrease in coverage and intensity as
the drier air mass gradually pushes across the I-10 corridor.
Westerly low level flow may advect low stratus or even some fog
from Apalachee Bay into the Suwannee Valley and north central FL
by the predawn hours on Saturday. Radiational cooling in the wake
of the frontal boundary should allow lows to fall to the mid and
upper 60s for inland southeast GA, while lows elsewhere generally
remain in the low to mid 70s.

&&

.SHORT TERM...
(Saturday through Sunday night)
Issued at 421 AM EDT Fri Jun 7 2024

Upper level ridging moves in from the west Saturday morning, with
weak high pressure at the surface creating drier conditions for
the weekend. Any chance for precipitation will be focused on NE FL
in the afternoon, mainly south of SR-20 (15-20%) and east of
US-17 (10-20%). Expect Sunny to mostly sunny skies with Daytime
temperatures well into the 90s possibly reaching 100 degrees in
some areas Sunday.

&&

.LONG TERM...
(Monday through Thursday)
Issued at 421 AM EDT Fri Jun 7 2024

Monday starts the beginning of what looks to be a rainy week,
with another cold front making its way in by Monday morning from
the Northwest. The front looks to hang around the FL/GA border
into the end of the week. Highest chances for precipitation will
be in the afternoon each day, though starting Tuesday chances of
precipitation each morning will be around 30-40% for SE GA and
40-70% for NE FL. Temperatures at the beginning of the week will
be in the mid to upper 90s, cooling into the upper 80s by mid
week.

&&

.AVIATION...
(06Z TAFS)
Issued at 230 AM EDT Fri Jun 7 2024

VFR conditions will prevail at the regional terminals. A brief
period of MVFR visibilities will be possible during the predawn
hours at VQQ, but confidence was too low to include in the
overnight TAFs. Scattered showers and thunderstorms are expected
to develop near the northeast FL terminals after 18Z Friday, with
activity mainly being triggered by a pinned Atlantic sea breeze
boundary and the inland moving Gulf coast sea breeze boundary. A
drier air mass will begin to filter into southeast GA during the
afternoon hours, and confidence for thunderstorms was too low to
include in the SSI TAF, where vicinity showers were included
after 19Z as the sea breeze gradually pushes onshore. Confidence
in coverage and intensity was too low to include anything other
than vicinity thunderstorms at the Duval County terminals and GNV.
A PROB30 group for briefly gusty winds and MVFR visibilities
during heavier downpours was included at SGJ after 22Z, with
activity at SGJ and GNV potentially lingering into the early
evening hours. Southwesterly surface winds sustained at 5-10 knots
overnight will shift to westerly towards sunrise, with speeds
increasing to around 10 knots before 15Z. The Atlantic sea breeze
boundary pushing onshore during the early afternoon hours will
shift winds to southeasterly at SGJ and southerly at SSI after
18Z. The Gulf coast sea breeze, which may also trigger at least
isolated convection around GNV, will shift surface winds back to
southwesterly after 20Z.

&&

.MARINE...
Issued at 421 AM EDT Fri Jun 7 2024

Offshore winds will prevail this morning ahead of a frontal
boundary that will approach our local waters from the northwest
this afternoon and evening. Scattered showers and thunderstorms
are expected to develop ahead of this boundary during the late
afternoon and evening hours, mainly across the northeast Florida
waters. This boundary will then weaken and dissipate over our
local waters on Saturday, with a weak pressure pattern prevailing
throughout the weekend. Seas of 2-4 feet will prevail both near
shore and offshore through the middle portion of next week.

Another frontal boundary will enter the southeastern states on
Monday, with this boundary then stalling over our local waters
during the the rest of next week. Scattered to numerous showers
and thunderstorms will develop along and ahead of this boundary on
Monday and Monday night, followed by waves of widespread showers
and thunderstorms impacting our local waters from Tuesday through
at least Thursday.

Rip Currents: Onshore winds developing this afternoon will combine
with a lingering southeasterly ocean swell to create a lower-end
moderate rip current risk at all area beaches. This lower end risk
may continue into Saturday at the northeast FL beaches, with a low
risk likely at the southeast GA beaches as wave heights fall to
around 1 foot or less. A low risk appears to be likely at all area
beaches on Sunday and Monday.

&&

.FIRE WEATHER...
Issued at 421 AM EDT Fri Jun 7 2024

Strengthening westerly transport winds will combine with elevated
mixing heights to create high to very high daytime dispersion
values nearly area-wide today. Westerly transport winds will
weaken on Saturday, but a drier air mass filtering into our region
may drop minimum relative humidity values to near critical
thresholds during the afternoon hours, especially for inland
locations along and north of Interstate 10. This dry air mass will
expand on Sunday, and westerly transport winds will become breezy
during the afternoon hours, creating high daytime dispersion
values.

&&

.CLIMATE...
Issued at 421 AM EDT Fri Jun 7 2024

Record high temperatures at our designated climate sites from
Today through Monday:


   June 7      June 8      June 9       June 10
              --------------------------------------------------
Jacksonville   100/1993    99/1993     101/1872     100/1954
Gainesville    99/1985     98/1907     99/1907      99/1899
Alma, GA       98/1993     100/1993    99/1993      103/1954
Craig Airport  96/1985     97/1985     97/2006      99/2006


&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  95  67  95  69 /  20  10  10   0
SSI  95  75  90  75 /  30  20  10   0
JAX  96  72  96  72 /  50  20  10   0
SGJ  95  74  94  75 /  50  20  10  10
GNV  95  73  97  70 /  30  10  10   0
OCF  95  73  97  72 /  30  10  20  10

&&

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

$$