textproduct: Key West

KEY MESSAGES

-Northeast to easterly breezes expected to peak at light to moderate tonight

-Near nil rain chances through the first half of the weekend.

-Breezes veering southeasterly and then southwesterly on Sunday

-Moisture increasing Sunday and Monday ahead of a possible frontal system early next week.

DISCUSSION

Issued at 416 AM EST Thu Dec 4 2025 Conditions are relatively uneventful this morning across the Florida Keys. Winds shifted northerly yesterday, and buoys along the reef and in the bay measured an increase to gentle to moderate breezes. GOES East satellite observations are able to highlight low cloud cover over the Florida Straits with nearly cloud free skies over the island chain. Temperatures and dew points along the island chain are in the lower 70s, so expect another muggy morning. Overall, the environment is primed to be muggy with north to northeasterly breezes across the CWA. Temperatures will remain slightly above normal for this time of year, and the lack of any sources of lift near the Keys resulted in near nil PoPs through tonight.

A high pressure system over the southeastern United States is modeled to begin breaking down this weekend as a Gulf frontal system develops into a low. Winds are forecast to clock from easterlies tomorrow to southwesterlies on Sunday night. The forecast challenge is what exactly will happen thanks to a potential cold front early next week. Statistical models and model ensembles indicate a copious amount of moisture will be directed over the Keys, primed for a cold frontal boundary or wind boundary to exploit. However, this low pressure system would not be attached to a pronounced longwave trough, which means the cold air behind the front is not as potent. This also means statistical models are going back and forth on how strong the front would be, when it would reach the Keys, and if it will pass over the Keys at all.

The forecast going out assumes a couple of features. Breezes are expected to circle the compass over the next seven days with northwesterlies by Monday. The pressure gradient is not expected to become sharp enough to cause breezy or windy conditions at this time. Current PoPs are set at 30 percent across the CWA Sunday night through Monday. A brief drop to normal temperatures was included in the forecast. Time will be the judge for this forecast, and changes are expected as we move closer to this event. Check back later for more details.

MARINE

Issued at 416 AM EST Thu Dec 4 2025 No watches, warnings, or advisories are in effect for the Florida Keys coastal waters. From synopsis, gentle to moderate northeasterly breezes will begin to veer southeasterly tonight. A messy high pressure system over the eastern CONUS will allow breezes to slacken to light to gentle over the weekend. Shower coverage will start to increase by the start of next week as breezes become southerly, and a cold frontal passage is possible early next week.

AVIATION

(06Z TAFS) Issued at 416 AM EST Thu Dec 4 2025 Light to gentle northeast to east winds will gradually veer and become east to southeast through the TAF period. Otherwise, VFR conditions will prevail.

CLIMATE

On this day in 1880, the daily record high temperature of 86F was recorded. Temperature data for Key West dates back to 1872.

PRELIMINARY POINT TEMPS/POPS

Key West 81 73 83 73 / 0 0 0 10 Marathon 80 74 81 74 / 0 10 0 10

KEY WATCHES/WARNINGS/ADVISORIES

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