FXUS62 KKEY 231449
AFDKEY

Area Forecast Discussion
National Weather Service Key West FL
1049 AM EDT Sun Aug 23 2026

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

.KEY MESSAGES...

- Conditions remain somewhat favorable for an island cloud line
  and associated waterspouts today.

- Rain and thunder chances will gradually return to near normal by
  the early to middle part of the week.

- Highs near 90 and dewpoints in the mid to upper 70s suggest 
  afternoon heat indices will peak at 105 to 108 degrees.

&&

.DISCUSSION...
Issued at 1016 AM EDT Sun Aug 23 2026
Surface analysis continues to depict a split ridge pattern, with
a climatological high pressure system centered between Bermuda and
the Azores in the North Atlantic, separated from a weak area of 
high pressure over the Gulf by a weak trough north of the Leeward
and Windward Islands. The 12z morning sounding at KEY sampled 
quasi-steady geopotential heights, with an uncapped environment, 
along with an unstable and moist environment below the 850 mb 
isobaric surface. The sounding also sampled mean southerly flow up
to around 5 kft, with GOES-19 visible satellite imagery 
indicating a discernible Cuban shadow progressing across the 
Straits of Florida.

A bit of a challenging forecast for the balance of today.
Convective allowing model (CAM) guidance suggests possible cloud
line formation later this afternoon, as heating of the South
Florida Mainland causes winds to variable for a bit this afternoon.
We are a bit skeptical of this, as ridging in the North Atlantic 
continues to become better established. The forecast calls for 
slight rain and thunder chances from any developing cloud line, 
temperatures peaking near 90, and dew points in the normal August 
mid to upper 70s. No changes proposed to the inherited forecast.

&&

.MARINE...
Issued at 1016 AM EDT Sun Aug 23 2026
Conditions will be somewhat favorable for island cloud line 
formation, mainly in the vicinity of the Lower and Middle Keys. 
Any cloud line may produce a few waterspouts. Mariners are 
reminded that a waterspout would most likely appear beneath a 
dark, flat bottom of a building cumulus line, just at the hint of 
rain.

From synopsis, a split ridge pattern remains in place across the 
Florida Keys coastal waters. This will promote generally light to 
gentle southeast to east breezes through tonight, becoming 
variable at times during the afternoon hours. While North Atlantic
ridging builds westward, east to southeast breezes will become 
more established from tonight through Thursday, becoming gentle 
and at times moderate during the overnight hours.
&&

.AVIATION...
(15Z TAFS)
Issued at 1016 AM EDT Sun Aug 23 2026
VFR conditions will prevail at both EYW and MTH island terminals 
through 12z Monday morning. Near surface winds will remain mostly 
southeasterly, though there is the potential for a period of light
and variable winds this afternoon continuing into the early 
evening hours. In addition, an island cloud line may develop late 
this afternoon or this evening, supporting the risk for vicinity 
showers and thunderstorms. Mention of VCSH is not explicitly in 
the TAF for now, with low confidence in cloud line development, 
although this will be monitored over the next several hours.

&&

.PRELIMINARY POINT TEMPS/POPS...
Key West  90  84  91  84 /  10  10  10  10 
Marathon  91  83  91  82 /  10  10  10  20 

&&

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

$$

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

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