textproduct: Key West

KEY MESSAGES

- Rain and thunder chances will peak this afternoon and evening.

- Much lower rain chances will begin overnight, continuing for the next several days.

- Conditions will remain seasonably warm and muggy, with heat indices approaching near 100F each afternoon through early next week.

DISCUSSION

Issued at 1015 AM EDT Wed Jun 10 2026 The Florida Keys island communities are likely in the window for their greatest rain and thunder chances for the next several days. GOES-19 water vapor imagery is depicting a clear Central American Gyre (CAG) in the vicinity of the Yucatan Peninsula at this late morning hour. CIMSS satellite- derived total precipitable water product highlights a ribbon of anomalously high water vapor content extending from the eastern Straits of Florida northwestward to portions of the Middle and Upper Keys. Much drier air is penetrating from the east, as a continental area of high pressure builds near the island of Bermuda. Often times, the dry air impinging on a plume of deep moisture can be a source of large- scale ascent, and that is certainly the case today. KBYX radar is highlighting scattered showers and isolated thunderstorms to the northwest of the Lower Keys, with stronger convection progressing northeastward in the eastern Straits of Florida associated with this moist-dry air mass interaction. Perhaps what is most interesting is the limited amount of lightning, which we hypothesize is attributed to very limited moisture in the 700-600 mb isobaric layer.

For the rest of today, the convective plume in the eastern waters should slowly pivot westward, first to the Middle Keys, then eventually to portions of the Lower Keys. It is tempting to raise PoPs to likely levels, but ample cirrus across the Island Chain may limited instability. Did nudge to high-end chance levels (around 50%). The cloud cover should also limit high temperatures a bit today, likely peaking in the mid 80s at most communities. No other changes proposed at this time.

MARINE

Issued at 1015 AM EDT Wed Jun 10 2026 No watches, warnings, or advisories are in effect for the Florida Keys coastal waters. However, isolated thunderstorms across the eastern Florida Keys marine zones will progress westward throughout the day. Any thunderstorm will be capable of producing locally higher and confused seas, as well as wind gusts well over the mean forecast sustained wind speeds would suggest.

From synopsis, a high pressure system over the North Atlantic will support gentle east to southeast breezes across the Florida Keys coastal waters through this evening. Shower and thunderstorm coverage will peak this afternoon, owed to the peripheral moisture surge from a Central American Gyre near the Yucatan Peninsula. The high pressure system will move further east into the North Atlantic overnight, allowing breezes to slacken to light to gentle. As the Gyre shifts slightly westward, the moisture plume will also shift west of the Florida Keys marine zones, supporting a drier pattern through the weekend.

AVIATION

(15Z TAFS) Issued at 1015 AM EDT Wed Jun 10 2026 Scattered showers with isolated thunderstorms will push across portions of the terminals through 00z this evening, first near MTH, then later near EYW. Have only included a window for VCSH for now through 00z due to the lack of significant coverage and localized impacts to visibilities and ceilings. After 00z, much drier air should support a significant reduction in convective activity in the vicinity of the terminals, continuing through the end of the TAF period.

PRELIMINARY POINT TEMPS/POPS

Key West 89 81 89 81 / 50 20 30 10 Marathon 88 81 89 81 / 50 20 20 10

KEY WATCHES/WARNINGS/ADVISORIES

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