199
FXUS62 KJAX 182316
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
716 PM EDT Fri Jul 18 2025

...New UPDATE, AVIATION...

.UPDATE...
Issued at 716 PM EDT Fri Jul 18 2025

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

No major updates on the forecast this evening. Strong
thunderstorms currently north of I-10 will begin to dwindle down
after sunset, with a mild night ahead. Saturday will be drier than
normal for summer, as a mid-level ridge treks across the area
lowering precipitation chances to about 20-30% over northeast
Florida. Main story tomorrow will be hot temperatures, with heat
indices approaching 105-110 degrees, Heat Advisories are likely
to be issued overnight for portions of the region.

&&

.SYNOPSIS...
Issued at 213 PM EDT Fri Jul 18 2025

Noon surface analysis depicts high pressure (1024 millibars)
positioned to the east of the Gulf Stream waters off the
southeastern seaboard. Meanwhile, the remnant circulation of
Invest 93L was meandering through the lower Mississippi Valley.
Aloft...ridging centered from the southeastern seaboard southward
through the Bahamas continues to gradually retrograde westward,
with this feature steering a weak trough slowly northward across
eastern portions of the Gulf and FL peninsula. Latest GOES-East
derived Total Precipitable Water imagery indicates that deep
tropical moisture remains in place across our area, with PWATs
generally around or just above 2 inches, while lower values in the
1.6 - 1.8 inch range were advecting northward from the Interstate
4 corridor in central FL. Temperatures have soared to the 90-95
degree range at most inland locations as of 18Z, with dewpoints
in the 70s yielding heat index values in the 100-108 degree
range thus far this afternoon. While a healthy cumulus field was
building across our region, convection thus far as remained to the
west of the Suwannee and Alapaha Rivers, where initiation was
being triggered by the inland moving Gulf coast sea breeze
boundary.

&&

.NEAR TERM...
(through Tonight)
Issued at 213 PM EDT Fri Jul 18 2025

Although subsidence will be strengthening with the retrograding
ridge approaching our region, some cooling aloft associated with
weak troughing aloft approaching from the south and plenty of low
level moisture should result in scattered late afternoon and
evening convection developing along inland moving sea and river
breeze boundaries, with a slightly higher coverage possible
towards sunset along the U.S. Highway 301 corridor, where
mesoscale boundaries are likely to collide. Southwesterly steering
flow could bring some of this activity back towards the I-95
corridor after sunset before activity diminishes later this
evening, or before midnight. A few storms will pulse as
convective boundaries collide and may briefly become strong early
this evening, with stronger storms being capable of producing
downburst winds of 40-50 mph, frequent lightning strikes, and
locally heavy downpours. Debris cloudiness from this evening`s
scattered convection will then gradually thin out overnight, with
lows only falling to the mid 70s inland, ranging to around 80 at
area beaches.

&&

.SHORT TERM...
(Saturday through Sunday)
Issued at 213 PM EDT Fri Jul 18 2025

This weekend, low/mid level ridging will shift from the Atlantic
over southern portions of the area centered over central to north
central FL and then shift westward into the NE Gulf waters. This
will limit chances for T`storms to mainly under 30 percent over
north central FL and under 20 percent over NE FL with silent pops
under 10 percent over most of SE GA. Sky cover will be mostly sunny
under the high and along with rising heights under the ridge will
allow high temperatures to rise into the mid to upper 90s on
Saturday and upper 90s to around 100 degrees inland. West to SW
flow will will pin the Atlantic seabreeze to the immediate coast
Saturday and offshore on Sunday allowing highs to reach the low to
mid 90s even at the beachfront.

The main story will be the heat index values this weekend as the
high temperatures also combine with dewpoints in the mid 70s to
create heat index values 108-112 degrees across much of the area,
except generally north and west of Waycross. Therefore, heat
advisories are likely for a majority of NE FL and along the SE GA
coast. &&

.LONG TERM...
(Monday through Thursday)
Issued at 213 PM EDT Fri Jul 18 2025

Next week, the low/mid level ridge will slide westward into the
north central Gulf as a trough/weak frontal boundary settles
southward along the Southeast U.S. coast towards the area.

For Monday, scattered to numerous showers and T`storms will
develop as moisture pools ahead of the trough/front with PWATS
climbing to 2.0 - 2.25 inches (90th percentile this time of
year). Winds will shift more easterly as the front approaches from
the north with highest T`storm chances west of highway 301.

By Tuesday and Wednesday, the front will slide into the area with
PWATs reaching near daily max values (above 2.3-2.4 inches). The
combination of high moisture, lift from the front and shortwave
energy aloft with a mid/upper trough moving SE off the eastern
seaboard will promote widespread showers and T`storms over our
area each day. While mid level temps will stay near to slightly
warmer than climatology (about -5 to -7 Celsius), steep low level
lapse rates and high moisture will allow for strong downburst
winds to occur between seabreeze and storm outflow collisions
along with locally heavy rainfall from heavy downpours and
frequent lightning.

On Thursday, the front will begin to weaken with some drier air
working in from the north into SE GA as weak high pressure extends
from near coastal New England into the Carolinas. This will limit
chances to scattered T`storms over SE GA and scattered to numerous
T`storms across NE FL.

Temperatures will begin the period above normal as highs remain in
the mid to upper 90s away from the coast with high heat index values
potentially into heat advisory levels Monday before highs trend back

&&

.LONG TERM...
(Monday through Thursday)
Issued at 213 PM EDT Fri Jul 18 2025

Next week, the low/mid level ridge will slide westward into the
north central Gulf as a trough/weak frontal boundary settles
southward along the Southeast U.S. coast towards the area.

For Monday, scattered to numerous showers and T`storms will
develop as moisture pools ahead of the trough/front with PWATS
climbing to 2.0 - 2.25 inches (90th percentile this time of
year). Winds will shift more easterly as the front approaches from
the north with highest T`storm chances west of highway 301.

By Tuesday and Wednesday, the front will slide into the area with
PWATs reaching near daily max values (above 2.3-2.4 inches). The
combination of high moisture, lift from the front and shortwave
energy aloft with a mid/upper trough moving SE off the eastern
seaboard will promote widespread showers and T`storms over our
area each day. While mid level temps will stay near to slightly
warmer than climatology (about -5 to -7 Celsius), steep low level
lapse rates and high moisture will allow for strong downburst
winds to occur between seabreeze and storm outflow collisions
along with locally heavy rainfall from heavy downpours and
frequent lightning.

On Thursday, the front will begin to weaken with some drier air
working in from the north into SE GA as weak high pressure extends
from near coastal New England into the Carolinas. This will limit
chances to scattered T`storms over SE GA and scattered to numerous
T`storms across NE FL.

Temperatures will begin the period above normal as highs remain in
the mid to upper 90s away from the coast with high heat index values
potentially into heat advisory levels Monday before highs trend back

&&

.AVIATION...
(00Z TAFS)
Issued at 716 PM EDT Fri Jul 18 2025

Lingering storms near the Duval sites prompted another hour of
VCTS, after that it will be a clear night with some fog expected
at VQQ pre-dawn. Saturday, storm chances are low, with the TAF
sites only at about 10-20% chance in the afternoon, so opted to
leave that out of the TAFs.

&&

.MARINE...
Issued at 1229 PM Fri Jul 18 2025

High pressure centered off the southeastern seaboard will shift
slowly westward towards our local waters tonight and Saturday.
Only isolated late afternoon and evening thunderstorms are
possible across the near shore waters through Saturday. Troughing
will then develop on Sunday over the southeastern states, with
this feature potentially sharpening near our local waters early
next week. Chances for showers and thunderstorms will increase
beginning late Sunday afternoon, with strong to isolated severe
afternoon and evening thunderstorms potentially impacting our
local waters each day next week. Seas of 2 to 3 feet will prevail
both near shore and offshore during the next several days.

Rip Currents: A persistent east-southeasterly ocean swell will
combine with developing onshore winds this afternoon to create a
lower end moderate risk at all area beaches. Similar conditions
are expected on Saturday, with a low risk possible by Sunday and
Monday due to low surf heights.

&&

.FIRE WEATHER...
Issued at 1229 PM Fri Jul 18 2025

Southwesterly transport speeds around 10 mph this afternoon will
combine with elevated mixing heights to create generally fair
daytime dispersion values, except good values for locations north
of Waycross in southeast GA and poor values at coastal locations,
where onshore surface winds will develop by mid-afternoon. Surface
and transport winds will become west-southwesterly on Saturday,
with breezy transport speeds developing north of the I-10 corridor
during the afternoon hours. These breezy conditions will combine
with elevated mixing heights to create high daytime dispersion
values across most of inland southeast GA, while good values
prevail elsewhere for inland locations, except fair values for
locations south of the I-10 corridor, where speeds will remain
light. Surface and transport winds will then shift to westerly on
Sunday, with breezy transport speeds combining with elevated
mixing heights to create high daytime dispersion values for inland
locations along and north of I-10, with good values forecast
elsewhere. Afternoon and evening thunderstorm coverage will
increase next week.

&&

.CLIMATE...
Issued at 1229 PM Fri Jul 18 2025

Daily record high temperatures at our designated climate sites
through Tuesday, July 22

                Today     Saturday  Sunday    Monday    Tuesday
                ---------------------------------------------------
Jacksonville    100/1887  101/2000  103/2000  102/1942  101/1942
Gainesville     100/1889  101/1899  100/1942  102/1942  99/1907
Alma, GA        102/2000  102/2002  104/2000  102/1942  100/1942
Craig Airport   98/1981   99/1993   100/2000  98/2015   99/1977

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  74  98  75  98 /  10  10   0  10
SSI  79  95  79  96 /  10  10   0  10
JAX  76  99  77 100 /  10  20   0  10
SGJ  76  95  77  96 /  10  20   0  10
GNV  74  97  74  98 /  10  20   0  10
OCF  75  95  75  96 /  10  30   0  20

&&

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

$$