textproduct: Key West

KEY MESSAGES

- A chances of showers with a slight chance of thunderstorms will persist through Wednesday night.

- Light to gentle east to southeasterly breezes will occasionally become variable through Wednesday evening.

- Conditions will be favorable for island cloud line formation near portions of the Florida Keys on Wednesday. Cloud line development will carry the risk of waterspouts.

DISCUSSION

Issued at 947 PM EDT Tue Jun 30 2026 Convection over the South Florida Mainland triggered several rounds of outflow-driven showers and thunderstorms across the Florida Keys coastal waters this evening. The highlight of the action pushed across portions of the Middle and Upper Keys, where a few nearby marine- based stations recorded peak wind gusts near 30 knots. This should come as no surprise given the 00z evening sounding sampled at KEY, which highlighted dry air in the 850-500 mb isobaric layer, supportive of DCAPE values over 1000 J/kg. Convection has since waned across the CWA, with KBYX and KAMX local Doppler radars only detecting a few remnant isolated showers. With little forcing for additional ascent, and many locations with convective instability eliminated, local meteorological reasoning suggests the Florida Keys and the adjacent marine zones should see limited additional shower and thunderstorm activity for the remainder of the overnight period. Temperatures should drop little overnight, remaining in the lower to mid 80s at most communities. Outside of removing mention of elevated wind gusts associated with stronger thunderstorms in the marine forecast for the remainder of the overnight period, no changes proposed.

MARINE

Issued at 947 PM EDT Tue Jun 30 2026 There are no watches, warnings, or advisories in effect for the Florida Keys local waters. From synopsis, a frontal boundary will stall across central Florida through Wednesday. This will keep winds light and variable during the day with brief nocturnal surges off the mainland in the evening and early portions of the overnight. Conditions will remain favorable for a cloud line to develop over, or across the waters adjacent to the Florida Keys on Wednesday. This may support the development of waterspouts. High pressure gradually builds back across the area Thursday with peaks and lulls resuming.

AVIATION

(00Z TAFS) Issued at 947 PM EDT Tue Jun 30 2026 VFR conditions are mostly expected at both EYW and MTH terminals through the TAF period. A weak frontal boundary will stall nearby the Island Chain which will instigate a couple rounds of showers and thunderstorms over the next couple days. Due to around average confidence for showers and potential thunderstorms, VCSH was included in the TAF for late Wednesday morning into Wednesday afternoon. Any activity will be capable of producing blinding downpours reducing CIGs to MVFR conditions with VIS a little less certain, gusty winds, and potential lightning.

PRELIMINARY POINT TEMPS/POPS

Key West 92 83 92 83 / 20 30 30 30 Marathon 90 82 89 83 / 20 30 30 30

KEY WATCHES/WARNINGS/ADVISORIES

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