375
FXUS62 KJAX 171136
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
736 AM EDT Mon Aug 17 2026

.KEY MESSAGES...

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

- Dangerously HOT Weather Continues this Week. Heat Advisory/Extreme
Heat Warning this Afternoon & Evening. Heat Advisories & Extreme Heat
Warnings Possible Tuesday through Friday

- Scattered Thunderstorms Today, Isolated Strong Storms Possible.
Main Impact Area: Northeast & North Central FL. Strong Storm Hazards:
Wind Gusts of 35 - 45 mph, Frequent Lightning Strikes,

- Scattered to Numerous Afternoon & Evening TStorms Tues  Sat. Strong
to Isolated Severe Storms are Possible Each Day, Mainly Along the
I-95

&&

.NEAR TERM /THROUGH TONIGHT/...
Main Highlights through Tonight:

- Heat Advisory Area-Wide Today, Extreme Heat Warning Coastal GA

- Isolated Strong Thunderstorms this afternoon and early evening,
Mainly Across Northeast FL

Another hot day will be in store today with the overall synoptic
setup changing overall little compared to the last few days as high
pressure ridging remains in place aloft. The main change that is
noteworthy revolves around a weakening front/trough that will drop
southward throughout the day today, settling just north of the
region tonight. This will increase the pressure gradient slightly,
while also inducing more of a continental west to northwest flow
across inland GA. These features, combined with slightly drier PWATs
moving into parts of southern GA associated with the troughing
feature, will limit convection for most areas across southeast GA
counties, while more scattered activity will be found across
northeast FL and the potential for stronger storms being towards the
nearly pinned sea breeze. Torrential rainfall and isolated strong to
marginally severe wind gusts will be the primary hazards given the
pulse type of showers and thunderstorms expected and pretty warm
temperatures aloft.

As mentioned above, certainly will be another hot day for many given
the subsidence aloft and west to southwest flow. Heat Advisories
are in effect for the entirety of the area, and Extreme Heat
Warning is in effect for Glynn and Camden. Peak heat indices
will be around 108 to 112 in heat advisory areas, and 113-115
for parts of Glynn and Camden Counties. High temperatures will
be generally in the mid to upper 90s, with a few readings around
100 possible over inland GA given the slightly drier conditions
and more time in the sun.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
Main Highlights This Period:

- Near Record Heat and Seasonably High Humidity Will Keep
Dangerously High Heat Index Values in Place Area-Wide on Tuesday

- Strong to Isolated Severe Thunderstorms Possible on Tuesday
Afternoon & Evening, Mainly for Locations South and East of Waycross

- Drier Air Mass Filters into Southeast GA on Wednesday, with
Scattered to Numerous Afternoon and Evening Thunderstorms Possible
South of Interstate 10

West-northwesterly flow aloft will prevail across the southeastern
states on Tuesday and Wednesday as "Heat Wave" ridging retrogrades
towards the Desert Southwest and broad troughing digs across the
Great Lakes and New England. This trough will continue to push a
frontal boundary slowly southward towards our area by midweek.
Deeper moisture will pool downstream of this boundary across our
region on Tuesday, with PWATs rising above 2.25 inches across
coastal southeast GA, northeast and north central FL. A drier air
mass may begin to filter into interior southeast GA by late
afternoon, keeping widespread convective activity confined to
northeast and north central FL. However, the presence of the
approaching front should still fire off scattered showers and
thunderstorms during the early to mid afternoon hours across
southeast GA. Strong to isolated severe thunderstorms will be
possible along the I-95 corridor during the late afternoon and early
evening hours as activity along the dominant eastward moving Gulf
sea breeze boundary encounters a pinned Atlantic sea breeze
boundary, likely causing storms to "pulse", with stronger storms
capable of producing downburst winds of 40-60 mph, frequent
lightning strikes, and locally heavy downpours

Breezy west-southwesterly low level flow will delay the development
of the Atlantic sea breeze at coastal locations, allowing near
record heat to extend all the way to area beaches. High temperatures
will climb to the 95-100 degree range before convection increases in
coverage and intensity, with another day of Extreme Heat conditions
possible for coastal southeast GA and possibly the I-95 corridor in
northeast FL, where Heat Index Values will peak in the 113-115
degree range. Heat indices elsewhere will peak in the Advisory range
of 108-112 degrees, except for locations north and west of Waycross,
where the incoming drier air mass may keep values closer to 105
degrees. Convection should shift eastward and offshore before
midnight on Tuesday night, with lows generally falling to the mid
and upper 70s.

PWATs will fall below 1.5 inches throughout southeast GA on
Wednesday as west-northwesterly flow advects a drier air mass
southward towards the I-10 corridor. However, the frontal boundary
will stall near or just north of the Altamaha River, and highs will
soar to around 100 for inland southeast GA, with mid to upper 90s
expected elsewhere. Dewpoints falling through the 60s in the drier
air mass across inland southeast GA should keep maximum heat index
values below Heat Advisory criteria, with values elsewhere across
coastal southeast GA, northeast and north central FL likely reaching
Heat Advisory criteria once again. Scattered to numerous afternoon
and evening thunderstorms will likely be confined to locations south
of I-10, with a few stronger storms again possible along the I-95
corridor south of Jacksonville. A few storms may linger across north
central FL on Wednesday evening, with fair skies forecast elsewhere
and lows again only falling to the mid and upper 70s.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
Main Highlights This Period:

- Near Record Heat and Dangerously High Heat Indices Continue on
Thursday and Friday.

- Scattered to Numerous Afternoon and Evening Thunderstorms Each Day
from Friday through the Upcoming Weekend

Troughing aloft will slowly dig over the eastern half of the nation
as "Heat Wave" ridging amplifies over the Rockies and the Desert
Southwest. This weather pattern will keep a wavy frontal boundary in
place over the Deep South, with deep-layered southwesterly flow
prevailing locally. The unseasonably dry air mass that will filter
into southeast GA on Wednesday will linger on Thursday, keeping
scattered afternoon and evening thunderstorms mostly confined to
areas from the Okefenokee Swamp southward. Near record heat will
otherwise continue, with highs again climbing to the 95-100 degree
range at most locations. Dewpoints will again fall through the 60s
across southeast GA, keeping heat index values below Advisory
levels, while values elsewhere across coastal southeast GA,
northeast and north central FL again reach the 108-112 degree range.
Convection may linger through the mid-evening hours on Thursday
along the I-95 corridor and north central FL, with fair skies after
midnight again yielding lows in the mid to upper 70s at most
locations.

Friday will likely be a transition to a more typical stormier
weather pattern as deepening southwesterly flow pools tropical
moisture along and downstream of a wavy stationary frontal boundary
that will remain in place across the southeastern states. Highs may
still soar to the mid and upper 90s, with heat index values rising
to at least Heat Advisory levels for much of our area. Scattered to
numerous afternoon and evening thunderstorms should develop across
our region as PWATs likely rise above 2 inches at most locations.
Scattered to numerous afternoon and evening thunderstorms are then
expected area-wide during the upcoming weekend, with convective
initiation during the early to mid afternoon hours likely keeping
temperatures in the low to mid 90s, with heat indices staying below
Heat Advisory thresholds for most of our area. Lows in the low to
mid 70s are forecast inland, while mid to upper 70s continue at
coastal locations.

&&

.AVIATION /12Z MONDAY THROUGH 12Z TUESDAY/...
VFR is expected to prevail through the morning hours. Westerly flow
will generally keep the Atlantic sea breeze near the coast, with
wind shifts only included at SSI and SGJ at this time. Convection is
expected to be found mainly across northeast FL, and have included
PROB30 groups for all sites accordingly except SSI where chances are
too low to include any TS mention at this time. Convection will
start to wane after 00Z, with VFR returning accordingly late in the
forecast period.

&&

.MARINE...


High pressure extending from the Bahamas westward across the Gulf
will gradually weaken this week as a frontal boundary sags southward
over the southeastern states. Westerly winds will prevail during the
next several days, with winds over the near shore waters shifting to
southerly during the afternoon hours as the Atlantic sea breeze
shifts slowly inland. Coverage of afternoon and evening showers and
thunderstorms will increase on Tuesday ahead of the approaching
frontal boundary, with southwesterly winds surging ahead of this
boundary on Tuesday evening possibly bringing speeds up to near
Caution levels. Coverage of afternoon and evening showers and
thunderstorms will shift to the northeast Florida waters on
Wednesday and Thursday.

Rip Currents: Prevailing offshore winds will strengthen slightly
today, though risk will remain low to moderate that will likely
continue through the end of the work week at all area beaches.

&&

.FIRE WEATHER...
- Heat Advisories And Extreme Heat Warnings In Effect Today

     MARGINALLY HIGH DAYTIME DISPERSIONS POSSIBLE ACROSS INLAND
- Southeast Georgia On Tuesday And Wednesday

Near record heat and seasonably high humidity values will result in
dangerously high heat index values nearly area-wide this week.
Extreme Heat Warnings are in effect today for coastal southeast
Georgia, with Heat Advisories posted elsewhere from 11 AM this
morning through 8 PM this evening. Otherwise, scattered afternoon
and evening thunderstorms are forecast for locations south and east
of Waycross and Brunswick in southeast Georgia and for all of
northeast and north central Florida today. West-northwesterly
transport winds will shift to west or west-southwesterly this
afternoon, with surface winds shifting to south or southeasterly at
coastal locations during the early to mid afternoon hours as the
Atlantic sea breeze moves slowly inland. Elevated mixing heights
will yield good daytime dispersion values at inland locations this
afternoon, with fair values forecast at coastal locations.

A similar weather pattern will prevail on Tuesday, with scattered
to numerous afternoon and evening thunderstorms possible. Elevated
mixing heights and slightly stronger westerly transport winds may
create marginally high daytime dispersion values across portions of
inland southeast Georgia on Tuesday and Wednesday afternoons.  A
drier air mass will filter into southeast Georgia on Wednesday and
Thursday, limiting chances for afternoon and evening showers and
thunderstorms. Scattered to numerous afternoon and evening
thunderstorm coverage will shift southward to northeast and north
central Florida by Wednesday and Thursday.

Fog Potential: Significant fog formation is not expected. Gusty and
erratic winds are possible within stronger thunderstorms.

&&

.CLIMATE...
Near record high temperatures are possible at some of our designated
climate sites during the next several days:

Monday, August 17:
KJAX: 99/1954
KGNV: 97/1954
KAMG: 104/1995
KCRG: 97/2005

Tuesday, August 18:
KJAX: 98/1954
KGNV: 98/1954
KAMG: 105/1995
KCRG: 96/2023

Wednesday, August 19th:
KJAX: 99/1900
KGNV: 100/1954
KAMG: 103/1995
KCRG: 97/2010

Thursday, August 20th:
KJAX: 101/1900
KGNV: 99/1900
KAMG: 104/1995
KCRG: 98/2016

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  97  77  98  76 /  10   0  40  20
SSI  96  80  98  79 /  20  10  40  40
JAX  96  77  96  77 /  40  20  60  40
SGJ  95  78  95  78 /  50  20  60  50
GNV  96  77  94  77 /  50  10  60  30
OCF  95  77  95  78 /  40  10  70  30

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory from 11 AM this morning to 8 PM EDT this evening
     for FLZ021-023-024-030-031-035-038-120-124-125-132-
     136>138-140-220-225-232-233-236-237-240-322-325-333-340-
     422-425-433-522-533-633.
GA...Heat Advisory from 11 AM this morning to 8 PM EDT this evening
     for GAZ132>136-149-151-152-162-163-250-264-350-364.
     Extreme Heat Warning from 11 AM this morning to 8 PM EDT this
     evening for GAZ153-154-165-166.
MARINE...None.

&&

$$