640
FXUS62 KJAX 191142
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
742 AM EDT Wed Aug 19 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 through Thursday. Heat Advisories
from 11 AM  8 PM Today for Locations South & East of Waycross. Heat
Advisories Likely Again on Thursday & Possible on Friday

- Scattered to Numerous Afternoon & Evening Thunderstorms Each
  Day. Main Impact Areas through Thursday: Locations South &
  East of Waycross. Afternoon & Evening TStorm Coverage
  Increases Friday through Sunday. Strong to Isolated Severe
  Storms are Possible Each Afternoon & Evening. Primary Hazards:
 Wind Gusts of 40-60 mph, Frequent Lightning Strikes, and Torrential,
 Slow Moving Downpours that Could Create Localized Flooding

&&

.UPDATE...

No major updates needed on the forecast this morning.

Highest probabilities for locations reaching 100 degrees will
be near the Altamaha river basin this afternoon. With the drier
air present over inland southeast Georgia (PWATs currently
around 1.5- 1.75"), apparent temperatures will be closer to
actual temperatures in the upper 90s to low 100s, below Heat
Advisory criteria. For the rest of the area, south of Waycross
and including the GA coast, hazardous heat index values
continue, ranging from 108-113 degrees.

Drier air in place over southeast Georgia will limit thunderstorm
potential today, whereas northeast Florida will again see scattered
to numerous showers and storms later today. Best shot for isolated
strong storms will be inland and south of I-10 after 2pm, with
plenty of heating/instability expected the primary concerns are
going to be wet downbursts and locally heavy downpours.

&&

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

- Near Record High Temperatures with Dangerous Heat Indices for
Portions of Our Area - Heat Advisories from 11 AM through 8 PM today
for Locations South and East of Waycross, GA.

- Strong to Isolated Severe Thunderstorms Possible this Afternoon
and Evening Across Northeast and North Central FL.

- Wet Microburst Potential within Stronger Storms, Possibly Creating
Wind Gusts of 40-60 mph, along with Frequent Lightning Strikes and
Localized Flooding.

Early morning surface analysis depicts weak high pressure (1019
millibars) situated over the northern Gulf. Meanwhile, a wavy
frontal boundary extends from the coastal Carolinas southwestward
across the Deep South and then westward across the lower Mississippi
Valley and the Southern Plains. Aloft..."Heat Wave" ridging extends
from the Desert Southwest eastward across the Southern Plains and
lower Mississippi Valley, while deep troughing over Hudson Bay,
Canada continues to gradually dig across the Upper Midwest and Great
Lakes states. Latest GOES-East derived Total Precipitable Water
imagery indicates that tropical moisture prevails for locations
south and east of Waycross in southeast GA, where PWATs were
generally in the 2 - 2.2 inch range, while a slightly drier air mass
prevails north of Waycross, where PWATs were around 1.75 inches.
Debris clouds that were leftover from evening convection on Tuesday
were persisting across portions of our area. Temperatures at 08Z
were mostly in the 70s, except around 80 at coastal locations, with
dewpoints generally in the low to mid 70s.

Northwesterly low and mid level flow will continue today as weak
surface ridging remains positioned over the northern Gulf. This flow
will gradually advect a drier air mass into interior portions of
southeast GA, with PWATs likely falling below 1.5 inches from around
Waycross northward. Dry weather is expected today north of Waycross,
where plenty of sunshine and dewpoints falling through the 60s this
afternoon will result in highs approaching 100. Heat index values
should remain just below Heat Advisory criteria (108 degrees) from
Waycross northward this afternoon.

Meanwhile, broad troughing developing along the eastern periphery of
the "Heat Wave" ridge over the FL peninsula will keep a tropical air
mass in place from the Okefenokee Swamp and coastal southeast GA
southward, where PWATs will remain near or just above 2 inches. This
will foster scattered convective development by mid-afternoon along
mesoscale boundaries such as the inland moving Atlantic and Gulf sea
breezes, in addition to the Lake George and St. Johns River breezes.
Lingering debris cloud cover early this morning will dissipate as
the day progresses, with highs soaring to near daily record values
this afternoon, or in the 95-100 degree range. Dewpoints in the low
or mid 70s will create another day of Heat Advisory conditions for
locations south and east of Waycross, where values will peak in the
108-112 degree range before late afternoon convection expands and
increases cloud cover across our area.

Convection should expand in coverage and pulse late this afternoon
and early this evening from the Okefenokee Swamp southward as
mesoscale boundaries and convective outflows collide. Plenty of
available instability could create a strong to isolated severe
thunderstorms, with wet microburst potential in pulsing storms that
could create wind gusts of 40-60 mph, along with frequent lightning
strikes and torrential downpours. Stronger storms may consolidate
along the I-10 and U.S. Highway 301 corridors in northeast and north
central FL towards sunset, and weak steering flow aloft could result
in heavy rainfall amounts and the potential for localized flooding,
especially at urban and normally flood prone locations. Convection
may migrate west of the U.S.-301 corridor towards I-75 during the
early to mid evening hours before activity diminishes towards
midnight. Thinning debris cloudiness is expected during the
overnight and predawn hours on Thursday, with lows in the 70s
forecast area-wide.

&&

.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
Main Highlights This Period (Thursday and Friday):

- Potential for strong to severe thunderstorms each afternoon

- Heat Advisories may be needed each day

A frontal boundary extending from low pressure over the Carolinas
will remain over southern GA this period. An upper trough will be in
place over the area this period. The low level flow will be from the
southwest, with the east coast sea breeze moving past I95 each
afternoon. The combination of diurnal heating, sea breeze
convergence and enhanced instability under upper trough will yield
above average chances for showers and storms in the afternoon and
evening hours this period.

Temperatures will remain above average this period. Heat advisories
may be needed each day.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
Main Highlights This Period (Saturday through Tuesday):

- Strong to severe thunderstorm chances each afternoon and evening

Area of low pressure will remain over the Carolinas throughout this
period, with a frontal boundary extending from it across GA. Upper
troughing will strengthen early this period, with waves passes
through the trough, before moving of to the east Monday. The
greatest chance for showers and storms this period will be Saturday.

Temperatures will trend a little above average this period.

&&

.AVIATION /12Z WEDNESDAY THROUGH 12Z THURSDAY/...
VFR conditions will prevail at the regional terminals through at
least 18Z Wednesday. Showers and thunderstorms will begin developing
near the northeast FL terminals towards 19Z, with dry weather and
VFR conditions expected to prevail at SSI throughout the forecast
period. PROB30 groups were maintained from around 20Z through around
01Z at the northeast FL terminals, with higher confidence for IFR
visibilities during heavier downpours at GNV and VQQ where TEMPOs
are now in place. Brief surface wind gusts around 30 knots are
expected during convection at the northeast FL terminals on
Wednesday afternoon and evening. Convection near the northeast FL
terminals should dissipate by 03Z Thursday, with VFR conditions
expected to prevail thereafter other than typical morning visibility
restrictions at VQQ.

&&

.MARINE...

Weak high pressure situated over the northern Gulf will maintain a
northwest to westerly wind flow across our local waters today. The
Atlantic sea breeze will push slowly inland this afternoon, shifting
surface winds to southeasterly this afternoon and then southerly
this evening, with speeds briefly surging around sunset before
diminishing overnight. Meanwhile, a stalled frontal boundary
positioned just north of the Georgia waters will remain in place
during the next several days. Scattered showers and thunderstorms
may impact the near shore waters adjacent to northeast Florida this
afternoon and evening and again on Thursday afternoon and evening.
Coverage of mainly afternoon and evening showers and thunderstorms
will then increase from Friday through the upcoming weekend
throughout our local waters as southwesterly winds prevail, with
afternoon sea breezes developing each day.

Rip Currents: Offshore winds and low surf heights will prevail
during the morning hours at area beaches during the next several
days. However, the afternoon sea breeze will coincide with the
outgoing tide during the next few afternoons, with breezy onshore
winds likely creating a lower end moderate risk at all area beaches
through Friday. Low surf heights and later outgoing tide times this
weekend could lower the risk at area beaches.

&&

.FIRE WEATHER...
- Patchy high dispersions Today

A frontal zone will remain stalled over southern GA this
period. Daily rounds of showers and thunderstorms are expected,
mainly in the afternoon and evening hours.

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

&&

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

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

Friday, August 21st:
KJAX: 101/1900
KGNV: 99/1983
KAMG: 100/1980
KCRG: 99/2016

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  99  74 100  75 /  10  10  10   0
SSI  98  79  95  79 /  20  10  10   0
JAX  98  75  96  76 /  60  20  40  10
SGJ  95  77  95  76 /  40  40  40  10
GNV  94  76  95  75 /  60  40  60  10
OCF  92  76  95  75 /  40  30  70  20

&&

.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 GAZ153-154-162-163-165-166-264-350-364.
MARINE...None.

&&

$$