textproduct: Key West

KEY MESSAGES

- A swath of Saharan dry air will remain across the Keys through the first half of the week. Shower chances will remain well below normal.

- Warm and muggy conditions will continue throughout the work week, with light breezes becoming variable at times.

AVIATION

(18Z TAFS) Issued at 115 PM EDT Mon Aug 17 2026 VFR conditions will persist at both EYW and MTH through 18z Tuesday afternoon, along with nil rain chances. Near surface winds out of the east will slacken continue to slacken through the afternoon evening, with winds becoming light and at times variable after 00z this evening.

PREV DISCUSSION

Issued at 423 AM EDT Mon Aug 17 2026 Upon zooming out to the synoptic perspective, two features will define weather across the Keys for the first half of the week. The first one is the aforementioned SAL. The immediate effects of the SAL are the mostly clear skies and lack of shower coverage across the Keys waters. Unfortunately, the absence of cloud cover means nothing will prevent the islands from heating rapidly during daytime hours. The second feature is that a col region is on track to set up over the Florida Keys. Lower pressure over the eastern US means a weaker subtropical ridge axis over the Gulf and Southern Florida, and thus light to gentle breezes across the Keys waters. Recent statistical model runs suggest periods of light and variable winds may be observed through Thursday or Friday at the latest.

When will this pattern break? The Saharan Air Layer is expected to wash out during the middle of the week, but that does not mean showers will redevelop en masse. Environmental winds are still in a pattern that would direct deep layer moisture away from the Florida Keys. Model ensembles indicate lower pressure and mid level troughing will persist over the Eastern United States through the end of the week. For better or worse, there is medium to high confidence that hot and muggy conditions with light to gentle, occasionally variable, winds will persist through the week and into next weekend.

MARINE

Issued at 1033 AM EDT Mon Aug 17 2026 Residual seas will gradually subside this afternoon. From synopsis, a nebulous flow pattern will support gentle east to southeasterly breezes becoming light and variable at times for the next several days. A Saharan Air Layer will keep shower and thunderstorm chances at near-nil through Tuesday night, with only a slight chance of rain and thunder expected for the latter half of the work week.

PRELIMINARY POINT TEMPS/POPS

Key West 92 81 92 82 / 0 0 0 10 Marathon 89 82 90 84 / 0 0 10 10

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...None.