textproduct: Key West

KEY MESSAGES

- Measurable rain chances will remain low through today through early next week, at generally 10% or less.

- Conditions will remain seasonably warm and muggy, but we may see heat index values above 105F, particularly along the Upper Keys, through Monday.

- A pocket of Saharan Air currently centered northeast of eastern Cuba will slowly move west across our area starting today and could linger through Wednesday.

DISCUSSION

Issued at 431 AM EDT Mon Jun 22 2026

Multiple remnant mesoscale boundaries have been periodically coming to life with showers and thunderstorms over night. Most of these boundaries have stayed out across the waters north and west of the island chain. As such, no precipitation has reached the island chain, unfortunately. A weak and broad high pressure lies from the Gulf Basin, over the Sunshine State, and out into the North Atlantic, which has kept us in a very nebulous pressure pattern. As a result, our winds have been highly mesoscale driven and started from the northeast to east early in the overnight but come back around from the east to southeast this morning. The stagnant flow and lack of precipitation means that Key West International Airport is on track to tie yet another warm low temperature.

Expanding our field of vision, there is a pocket of Saharan Air Layer (SAL) centered across the Southeastern Bahamas and slowly trekking west- northwest towards the Keys. This will gradually invade from east to west through the day today. Along the leading edge there may be enough lift to support a few isolated showers and thunderstorms as it pushes through. Otherwise, once it's passed through it will essentially shutdown convection chances for the Keys through Wednesday. Thereafter, the aforementioned weak high, will attempt to strengthen slightly, allowing for winds to increase. At the same time, pockets of relatively more moist air will pivot along the periphery. These pockets of moisture do not look to be terribly impressive and will struggle to move in on the back side of the SAL. To that point, rain chances will hold generally at 10 percent or less through the forecast period.

MARINE

Issued at 431 AM EDT Mon Jun 22 2026

Widely scattered showers and possible isolated thunderstorms will wax and wane across mainly the waters north of the island chain this morning. As a plume of Saharan Air Layer slowly filters in from the east, could see a narrow line of showers and thunderstorms develop and move across the eastern Straits of Florida. Otherwise, weak high in place will flux in strengthen over the next several days, leading to breezes peaking at night and then lull during the day. Expecting generally light to gentle breezes with the exception of gentle to occasionally moderate breezes across the Straits of Florida. High pressure will begin to strengthen starting Wednesday, leading to a more general freshening of breezes.

AVIATION

(06Z TAFS) Issued at 431 AM EDT Mon Jun 22 2026

Generally expecting VFR conditions today. Convection north and north of the EYW terminal will push to the west and gradually diminish through sunrise. A Saharan Air Layer moving in from the east could produce a pop-up shower or thunderstorm along the leading edge as it moves through during the late morning and afternoon. Confidence at this time is too low to include mentions in the current TAF cycle.

PRELIMINARY POINT TEMPS/POPS

Key West 90 84 90 84 / 10 10 10 10 Marathon 89 84 89 83 / 10 10 10 10

KEY WATCHES/WARNINGS/ADVISORIES

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