textproduct: Key West

KEY MESSAGES

- Expect rain and thunder chances to decrease this afternoon and this evening.

- Breezes are on track to slacken by the end of the weekend and periods of light and variable winds are expected next week.

- A swath of Saharan dry air will push across the Keys for the second half of the weekend, lasting through early next week.

DISCUSSION

Issued at 421 AM EDT Sat Aug 15 2026 A busy night across the Florida Keys waters quieted down before sunrise. An outflow boundary racing north from Cuba, elevated moisture throughout the atmosphere, and boundaries moving west from the Florida Peninsula were able to sustain long lived thunderstorms. By midnight, most of these showers had exhausted the ambient instability. That led to convective collapse south of the island chain, and gusts in excess of 34 knots were measured at Long Key, American Shoal Light, and the Florida Keys Marathon International Airport. While thunderstorms were able to pulse up over the Gulf waters, the gust front signaled the last hurrah for overnight convection. Overnight temperatures were slightly cooler in the wake of these showers, but expect higher temperatures to return this afternoon.

Drier conditions are returning to the Florida Keys later tonight. GOES East satellite imagery highlights a broad region of drier air over the Bahamas moving towards the Florida Peninsula. CIMSS MIMIC Layer TPW estimates a change from over 2 inches of PWAT to below 1.5 from the Upper Keys to Andros Island. There is high confidence that this is part of a Saharan Air Layer that is making its way towards North America. While a line of showers cannot be ruled out along the leading edge of the SAL, expect the upcoming week to be significantly drier than normal. In addition, numerical models suggest lower pressure will develop over the North Atlantic and eastern United States. Winds across the Keys are primed to slacken to light breezes, occasionally variable, all while the environment heats up across the island chain. Overall, expect the upcoming week to be warmer than normal light winds. Heat will be the primary risk, so try to do what you can to mitigate warmer temperatures.

The National Hurricane Center is tracking two possible areas for development over the central Tropical Atlantic. Currently, both systems are considered to have a low chance of development. Even in the event one of the systems develops into a tropical depression, neither system poses a threat to the Florida Keys at this time.

MARINE

Issued at 421 AM EDT Sat Aug 15 2026 No watches, warnings, or advisories are in effect for the Florida Keys coastal waters. From synopsis, gentle to moderate east to southeast breezes across the Florida Keys will start to slacken before the start of the work week. The subtropical ridge is expected to weaken as a mid latitude trough descends into the Atlantic from the eastern United States. Periods of light and variable breezes are possible early next week as a result. Meanwhile, a Saharan Air Layer is forecast to move across the Keys waters early next week. There is high confidence shower coverage will be low for most of the forecast period.

AVIATION

(06Z TAFS) Issued at 421 AM EDT Sat Aug 15 2026 VFR conditions will prevail at EYW and MTH for the upcoming TAF period. A plume of moisture will linger over the island chain in the morning hours, and showers may be able to develop before sunset. Near surface winds are expected to remain near ten knots throughout the TAF period. A Saharan Air Layer is primed to move over the Florida Keys late in the period, and shower chances are primed to decrease significantly by the end of the period.

PRELIMINARY POINT TEMPS/POPS

Key West 92 82 92 82 / 20 10 10 0 Marathon 90 84 90 83 / 20 10 10 0

KEY WATCHES/WARNINGS/ADVISORIES

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