452
FXUS62 KJAX 160745
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
345 AM EDT Fri May 16 2025

...NEAR RECORD HEAT CONTINUES THROUGH MIDWEEK NEXT WEEK...
...AREAS OF LOCALLY DENSE FOG POSSIBLE INLAND DURING THE EARLY
MORNING HOURS THROUGH THE WEEKEND...
...NEXT COLD FRONTAL PASSAGE ON LATE WEDNESDAY OR THURSDAY...

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 344 AM EDT Fri May 16 2025

Overnight surface analysis depicts Atlantic ridging extending its
axis westward across the FL peninsula through the eastern Gulf.
Meanwhile, a cold front extends from the Great Lakes southwestward
through the Arklatex region. Aloft...ridging over the Gulf
continues to expand northeastward towards our region. Otherwise,
deep troughing over the Dakotas and Upper Midwest was progressing
slowly eastward. Latest GOES East derived Total Precipitable Water
imagery indicates that PWATs remain mostly in the 1 - 1.25 inch
range, with slightly higher amounts around 1.4 inches located near
the Altamaha River in southeast GA. Mostly thin cirrus cloudiness
continues to spill over the top of the Gulf ridge that was
building towards our area, with latest nighttime infrared
satellite imagery showing low stratus cloud cover developing along
and north of the Interstate 10 corridor in the Suwannee Valley.
West-southwesterly winds remain sustained at 5-10 mph at most
locations as of 07Z, which was keeping temperatures mainly in the
upper 60s and lower 70s, with dewpoints generally in the mid to
upper 60s.

&&

.NEAR TERM...
(Today and Tonight)
Issued at 344 AM EDT Fri May 16 2025

Low stratus clouds and some potential for patchy to areas of fog
will expand across the Suwannee Valley and portions of inland
southeast GA through the predawn and early morning hours, with
this low cloud cover likely reaching the U.S. Highway 301 corridor
towards sunrise. Lower clouds should remain west of the I-95
corridor this morning, with mixing after sunrise likely allowing
these lower ceilings to lift by mid-morning at inland locations.
Periods of mostly thin cirrus will continue to spill overtop of
the ridge and across our area through tonight. Otherwise, west-
southwesterly low level flow will delay the development of the
Atlantic sea breeze boundary to the early to mid afternoon hours
at coastal locations. A dry and increasingly subsident atmosphere
will allow for dewpoints to potentially fall to around 60 at
inland locations this afternoon as filtered sunshine allows
temperatures to soar to the mid and upper 90s at inland locations.
These values will challenge daily record high temperatures at our
designated climate sites (see "Climate" section below for
details). This dry air mass will keep maximum heat index values
in the upper 90s to around 100, with coastal locations more likely
to experience "feels-like" temperatures near the century mark as
the afternoon sea breeze moves slowly inland, bumping coastal
dewpoints back to the upper 60s to around 70 by the mid to late
afternoon. This sea breeze will struggle to reach the I-95
corridor during the late afternoon, and its delayed development
will yield highs in the lower 90s all the way to area beaches
during the early to mid afternoon hours before an onshore breeze
drops temperatures back to the upper 80s before sunset.

Another round of low stratus and potentially some fog development
is expected across the Suwannee Valley and portions of inland
southeast GA after midnight, with some potential for eastward
expansion of these low stratus ceilings and fog towards sunrise.
Light westerly low level winds will otherwise prevail overnight,
with lows only falling to the upper 60s inland and around 70 at
coastal locations.

&&

.SHORT TERM...
(Saturday through Sunday night)
Issued at 344 AM EDT Fri May 16 2025

High pressure will be centered to the southeast Saturday, with
ridging extending west across southern FL. A cold front will drop
into central GA Saturday afternoon. This pattern will then linger
through Sunday night. The real question this period will be whether
the front sinks far enough to be a focus for convection into SE GA.
A few weak upper waves pass along the frontal zone during the
period, which could cause the boundary to waiver a bit from north to
south, otherwise there is not much support to push boundary into
forecast area. So, at this point precipitation chances will be kept
on the low side this period over SE GA, and NE FL will be kept dry.

Temperatures will remain above seasonal averages throughout this
period. With dewpoints largely in the 60s throughout this time
frame, heat will not make it to advisory levels.

With the prevailing flow from the west southwest between the ridge
and the front, the heat will make it all the way to the beaches,
with little, if any afternoon push inland of the east coast sea
breeze.

&&

.LONG TERM...
(Monday through Thursday)
Issued at 344 AM EDT Fri May 16 2025

The high pressure ridge will lift to the north into central FL
Monday into Tuesday, with frontal boundary also moving further
to the north. A ridge will be in place at 500mb. Subsidence under
these two ridges and moisture still on the low side will provide
dry weather for the start of the week.

The ridge will move away to the southeast Tuesday night, as an upper
trough digs into the southeastern US, and a cold front moves into
southeastern US.

Long term models have timing differences in the cold frontal
passage, but in general looking at the Wednesday afternoon to
Thursday afternoon time frame. Too early to determine potential
strength of storms on the frontal passage, but indications are that
there will be a fairly significant thermal boundary with it,
suggesting it could be a strong passage.

Temperatures will continue above average throughout this period.
Thursday would start a trend toward lower readings.

&&

.AVIATION...
(06Z TAFS)
Issued at 153 AM EDT Fri May 16 2025

VFR conditions will prevail at the regional terminals through at
least 08Z. Low stratus ceilings and fog are expected to advect
across the Suwannee Valley towards the GNV and VQQ terminals after
08Z, with enough confidence in this scenario to indicate
prevailing MVFR visibilities at VQQ towards 09Z and at GNV towards
11Z. We left TEMPO groups for LIFR conditions at VQQ through
around 12Z and for IFR conditions at GNV through around 13Z. Fog
and low stratus could approach JAX after sunrise, but confidence
was too low to indicate sub-VFR conditions at this time.
Otherwise, VFR conditions will then prevail at the regional
terminals by 14Z. West-southwesterly surface winds will remain
sustained around 5 knots at the inland terminals overnight and
5-10 knots at the SSI and SGJ coastal terminals. The Atlantic sea
breeze boundary will develop near the coastal terminals towards
18Z, with surface winds shifting to southeasterly at SGJ and
south-southeasterly at SSI, where sustained speeds will increase
to around 10 knots. The sea breeze may push inland to CRG towards
22Z, where winds will become south-southeasterly briefly before
sunset. West-southwesterly surface winds will otherwise increase
to around 10 knots by 19Z at the rest of the inland terminals,
followed by speeds diminishing to around 5 knots by 06Z Saturday.

&&

.MARINE...
Issued at 344 AM EDT Fri May 16 2025

Atlantic high pressure will continue to extend its axis across the
Florida peninsula through the weekend and early next week, keeping
a prevailing offshore wind flow in place across our local waters.
The afternoon sea breeze will shift winds to south and
southeasterly for the near shore waters through around sunset,
with winds shifting to southerly during the evening hours. Seas of
2 to 4 feet will prevail both near shore and offshore during the
next several days. A weakening frontal boundary will enter the
southeastern states late this weekend, but this front will stall
to the north of the Georgia waters. An isolated late afternoon or
evening thunderstorm is possible over the Georgia waters on
Sunday. The next significant frontal boundary will move across
our local waters by late Wednesday or Thursday, possibly
accompanied by widely scattered showers and thunderstorms.

Rip Currents: Prevailing offshore winds and low surf heights
should keep the risk low through at least midweek next week.
Afternoon sea breezes will increase surf heights somewhat, but a
weak easterly ocean swell will not raise the risk appreciably.

&&

.FIRE WEATHER...
Issued at 344 AM EDT Fri May 16 2025

A dry and increasingly hot air mass will result in minimum
relative humidity values falling to the 30-35 percent range at
most locations today and again on Saturday. Breezy westerly
transport winds will create good daytime dispersion values this
afternoon. Westerly transport winds will strengthen even further
on Saturday and will combine with elevated mixing heights to
create high to very high daytime dispersion values on Saturday and
Sunday. The Atlantic sea breeze should remain pinned to the east
of I-95 through the mid to late afternoon hours today and again
on Saturday, with this boundary expected to push further inland
on Sunday afternoon.

&&

.CLIMATE...
Issued at 344 AM EDT Fri May 16 2025

Daily Record High Temperatures through Tuesday at our designated
climate sites:


                  Fri 5/16  Sat 5/17  Sun 5/18  Mon 5/19  Tues 5/20
                 --------------------------------------------------
Jacksonville      96/1995   96/1995   96/1899   97/1960   99/1962
Gainesville       98/1896   96/1915   97/1930   99/1899   97/1938
Alma, GA          95/1990   94/2001   95/2001   97/1960   99/1962
Craig Airport     94/1994   93/2001   93/2001   92/2006   97/2006

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  93  69  92  70 /   0   0   0   0
SSI  92  71  92  74 /   0   0   0   0
JAX  97  68  96  69 /   0   0   0   0
SGJ  93  70  96  69 /   0   0   0   0
GNV  94  67  94  67 /   0   0   0   0
OCF  92  68  93  67 /   0   0   0   0

&&

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

$$