textproduct: Key West

KEY MESSAGES

- Rain and thunder chances will remain elevated (30-40%) through today.

- Lower rain chances will ensue tonight, lasting through early next week.

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

DISCUSSION

Issued at 430 AM EDT Thu Jun 11 2026 Weather continues to be a bit more active than expected across the Florida Keys. KBYX radar returns continue to highlight pulses of individual showers across the bayside waters. Seasonably muggy weather continues with dew points in the lower to mid 70s across the Florida Keys waters. Breezes have slackened to light to gentle, which means the air is about to feel a bit more stagnant. CIMSS MIMIC returns continues to estimate over 2 inches of PWAT within the air streaming across the Keys. Even though GOES East satellite observations hint at a break in cloud cover, the environment remains primed for showers today and tonight. The decrease in wind speed also suggests a higher possibility of sea and land breeze interactions. Thus, opting to keep a chance of showers in the forecast for today.

The weather pattern is in a state of transition across Florida today. A Central American Gyre over the Yucatan continues to direct moisture-rich air from the Caribbean into the eastern Gulf. The problem is that the gyre is trending west while high pressure in the Atlantic shifts eastward. The pressure gradient across the Keys is on track to collapse while the CAG pulls moisture towards Mexico. That implies light breezes later this week, all while the CAG meanders over the Bay of Campeche. Moisture totals are not on track to change dramatically. Model ensembles show very little change in the dew points across the Keys. Meanwhile, a very deep trough is primed to form over the eastern United States. That suggests the absence of a strong surface high north of Florida, and thus light breezes continue into the weekend. Models suggest a lack of showers and thunderstorms late into the forecast, but in a light wind regime mesoscale effects become important. Local sources of lift would allow drier air to generate rain, and tropical clouds produce rainfall very efficiently. The only certainty is that muggy conditions are on track to continue next week, and we may begin to see 100 degree heat indices across the Keys. While the official start of summer is not for another eleven days, summertime weather has arrived across the island chain.

MARINE

Issued at 430 AM EDT Thu Jun 11 2026 No watches, warnings, or advisories are in effect for the Florida Keys Coastal Waters. From synopsis, breezes are beginning to subside to light to gentle across the Florida Keys coastal waters. High pressure over the Atlantic continues to move east while a tropical wave over the Yucatan moves west, and both features are reducing the pressure gradient across the Keys. The moisture associated with the moisture plume is primed to shift westward, which would decrease shower and thunderstorm coverage over the maritime zones.

AVIATION

(06Z TAFS) Issued at 430 AM EDT Thu Jun 11 2026 VFR conditions will prevail for the upcoming TAF period. Near surface winds will remain southeasterly while decreasing towards 5 knots. Occasional bouts of CIGs may develop over the waters, but there is not sufficient confidence in the timing of nearby VCSH. Thus, leaving VCSH out of the TAFs for now.

PRELIMINARY POINT TEMPS/POPS

Key West 89 81 89 81 / 40 10 20 10 Marathon 89 81 89 80 / 40 10 20 10

KEY WATCHES/WARNINGS/ADVISORIES

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