054
FXUS62 KKEY 081949
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
349 PM EDT Tue Sep 8 2026

...New MARINE, AVIATION, PREV DISCUSSION...

.KEY MESSAGES...

- Moisture will linger across the region through midweek,
  supporting rain and thunderstorm chances.

- The primary threat for any stronger thunderstorms will be
  dangerous lightning strikes. When thunder roars, go indoors. If
  on a boat, stay low, or go below.

- Heat index values will range from 100-108 degrees daily, with
  little relief in the muggy conditions overnight. Know the signs
  of heat stress, take frequent breaks, and stay hydrated.

&&

.MARINE...
Issued at 349 PM EDT Tue Sep 8 2026

From synopsis: The Florida Keys coastal waters will initially
remain in a broad nebulous pressure pattern this evening, leading
to light and variable winds. By early Wednesday, western extent of
the Atlantic Ridge will begin building in, allowing breezes to
become more easterly and freshen to gentle to moderate. Waves of
low- level moisture pushing across the Keys will support elevated
rain and thunder chances through Tuesday, possibly returning to
near normal by mid week.

&&

.AVIATION...
(18Z TAFS)
Issued at 349 PM EDT Tue Sep 8 2026

Convection is generally on the downward trend and expecting VFR
conditions for the rest of the afternoon and into the evening.
There is a chance of showers and possibly thunderstorms developing
after midnight but confidence on exact timing remains low. Will
leave mentions of VCSH or VCTS for future amendments.

&&

.PREV DISCUSSION...
Issued at 400 AM EDT Tue Sep 8 2026

Weak lower level troughing remains across the Florida peninsula
this morning. This has contributed to the atmosphere remaining
very moist. Last evenings sounding had a precipitable water of
2.25 inches which was above the 90th percentile for the date.
There was a sliver of lower level inhibition, but CAPE was more
than ample and lower level moisture was quite high. Surface winds
and steering flow remain quite weak and often variable.

Over the next few days, the troughing across Florida will wash out
as a pressure ridge builds east southeastward off the Atlantic
Coast and down along the Gulf coast. As this takes place, variable
surface breezes will gradually firm up out of the east. Moisture
and instability will remain high, while inhibition limited. This
along with the increasing flow should keep shower and thunderstorm
chances near to slightly above normal. Seasonable temperatures
will continue with highs near 90 and lows in the lower to mid 80s.

The surface ridge will retreat into the Atlantic late in the week
and this evening as it shifts down the Florida peninsula. This
will tip breezes a bit more southeasterly whilst continuing the
usual peaks and lulls. Some drier air may arrive Friday, but will
be followed by increased moisture during the weekend.

&&

.KEY WATCHES/WARNINGS/ADVISORIES...
FL...None.
GM...None.
&&

$$

Public/Marine/Fire...LIW
Aviation/Nowcasts....LIW
Data Acquisition.....LIW

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