422
FXUS62 KTAE 181038
AFDTAE

Area Forecast Discussion
National Weather Service Tallahassee FL
638 AM EDT Tue Aug 18 2026

...New AVIATION...

.KEY MESSAGES...
Issued at 638 AM EDT Tue Aug 18 2026

- Long-duration hazardous heat wave continues for much of this
  week.Heat products will keep being issued accordingly. Very
  warm nighttime temperatures offer little relief. Please exercise
  heat safety: www.weather.gov/safety/heat.

- Daily chances for thunderstorms remain in the forecast. Strong-
  gusty winds, frequent lightning and locally heavy rain are the
  main threats.

- The heat wave is poised to break late this week or early
  weekend, which likely opens the door for convectively active
  weather.

&&

.SHORT TERM...
(Today and Tonight) Issued at 239 AM EDT Tue Aug 18 2026

Oppressively hot conditions are on the menu once again today.
High temperatures are forecast to be in the mid to upper 90s
(isolated 100 possible). Extreme Heat Warning goes into effect
from 11AM EDT/10AM CDT to 8PM EDT/7PM CDT for all of our FL
counties and adjacent first row of SW GA counties. Heat indices
near or above 113 degrees are expected at those locations during
that time. A Heat Advisory is in place elsewhere for heat indices
up to 112 degrees. Widespread lows in the mid to upper 70s
maintain uncomfortably warm overnight weather.

Scattered thunderstorms develop this afternoon, especially in the
FL Panhandle where prevailing low-level NW winds converge with
the seabreeze zone. Additional cell formation occur from outflow
boundary collisions. High instability and Precipitable Waters of
2+ inches will make convection capable of strong-gusty winds,
frequent lightning, and locally heavy rain. An isolated severe
downburst or two would not be surprising. One potential convective
"quirk" is to monitor is a southward moving outflow boundary from
decaying thunderstorms overnight across Central GA. This feature
may serve as a separate focus for thunderstorms. Overall activity
winds down after sunset.

&&

.LONG TERM...
(Wednesday through Monday) Issued at 239 AM EDT Tue Aug 18 2026

Wednesday`s set up looks a bit interesting. Maritime convection
appears to get going in the morning from a remnant outflow
boundary and/or lobe of vorticity aloft spinning over the NE Gulf.
By the afternoon, showers and thunderstorms shift inland,
particularly focusing across the FL Big Bend in closer proximity
to the aforementioned "vort lobe". Convective debris emanating
from offshore, elevated rain chances from the Forgotten Coast to
the eastern I-10 corridor, and relatively lower dew points
spreading from the north may act to temper the heat to some degree
(no pun intended) across portions of the Tri-State area. High
temperatures are currently forecast to be in the mid to upper 90s
with a north- south gradient of max heat indices ranging from the
low 100s in most SE AL & SW GA to mid 110s along/south of the FL
state line. If trends hold, then a Heat Advisory may not be
necessary areawide, but rather be confined to our FL zones.

By Thursday, the persistent upper ridge responsible for this
long- duration heat wave retrogrades westward in response to more
pronounced troughing across the Eastern US. Upper height falls and
drier air continuing to filter in from the north should lower
heat indices to less oppressive levels outside of most FL
counties. A residual vorticity lobe spinning over the NE Gulf
confines the highest rain chances to the seabreeze front and
offshore. For Friday- Saturday, the weather is looking less hot,
but unsettled as troughing sharpens and digs southward. A frontal
boundary sags into the region and provides an additional focus for
convection while also introducing some NW flow aloft. This
pattern following a heat wave break tends to support a
convectively active setup that may involve a Mesoscale Convective
System diving SE from the Upper MS Valley. Stay tuned. Rain
chances decrease on Sunday as the trough lifts to our NE.

Highs in the 90s and lows in the 70s will continue to be common
during the long-term period. However, we may not be issuing any
heat products for the first time in many days this weekend as
widespread heat indices drop to below 110 degrees.

&&

.AVIATION...
(12Z TAFS)
Issued at 638 AM EDT Tue Aug 18 2026

VFR conditions are generally expected to prevail throughout the
TAF period. PROB30 remains in place for potential thunderstorms
impacting area terminals this afternoon.

&&

.MARINE...
Issued at 239 AM EDT Tue Aug 18 2026

Persistent high pressure maintains favorable boating conditions
the next several days outside of thunderstorms, for which chances
increase Wednesday through Saturday. Prevailing gentle to moderate
west winds are forecast with daily afternoon seabreezes across
the immediate nearshore legs.

&&

.FIRE WEATHER...
Issued at 239 AM EDT Tue Aug 18 2026

The main fire concerns continue to be areawide hazardous heat
conditions persisting through at least mid week and daily chances
for afternoon thunderstorms. In addition, high dispersions can be
expected in parts of SE AL and SW GA this afternoon.

High temperatures well into the 90s will be common with heat
indices of 108 to 115+ degrees. Thunderstorms will be capable of
frequent lightning, gusty/erratic winds, and locally wetting rains
are additional threats. Prevailing west to NW winds are forecast
outside of daily afternoon seabreezes across our Florida counties.

The heat and thunderstorm activity should be greatest across the
FL zones. Overall oppressively hot weather subsides this weekend.

&&

.HYDROLOGY...
Issued at 239 AM EDT Tue Aug 18 2026

Thunderstorms will be capable of producing localized nuisance
flooding in urban, poor-drainage, and low-lying areas. Otherwise,
there are no significant hydrological concerns the next several
days. All area rivers are currently running well below action
stage.

&&

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not requested. However, spotters are always
encouraged to safely report significant weather conditions when they
occur by calling the office or tweeting us @NWSTallahassee.

&&

.PRELIMINARY POINT TEMPS/POPS...
Tallahassee   97  77  97  75 /  40  10  50  10
Panama City   94  81  93  80 /  30  10  20  10
Dothan        97  76  97  74 /  30  10  20  10
Albany        98  76  98  74 /  10  10   0   0
Valdosta      98  76  98  74 /  20  10  20   0
Cross City    94  78  94  77 /  30  10  40  10
Apalachicola  93  81  92  80 /  20  20  40  30

&&

.TAE WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory from 10 AM this morning to 7 PM CDT this evening
     for FLZ007.

     Extreme Heat Warning from 11 AM EDT /10 AM CDT/ this morning to
     8 PM EDT /7 PM CDT/ this evening for FLZ008>019-027>029-034-
     108-112-114-115-118-127-128-134-326-426.

     High Rip Current Risk from noon EDT /11 AM CDT/ today through
     late tonight for FLZ112-114.

GA...Heat Advisory from 11 AM this morning to 8 PM EDT this evening
     for GAZ120>131-142>148-161.

     Extreme Heat Warning from 11 AM this morning to 8 PM EDT this
     evening for GAZ155>160.

AL...Heat Advisory from 10 AM this morning to 7 PM CDT this evening
     for ALZ065>069.

GM...None.
&&

$$

SHORT TERM...IG3
LONG TERM....IG3
AVIATION...Oliver
MARINE...IG3
FIRE WEATHER...IG3
HYDROLOGY...IG3