textproduct: Key West

KEY MESSAGES

-Drier conditions will persist through tonight, thereafter, moisture will begin to return and elevated rain changes will prevail through the weekend.

-Light to gentle breezes will briefly slacken further early this weekend as high pressure sits over the SE CONUS.

-Small Craft Advisory headlines are becoming increasingly likely for Monday and Monday night after a strong front pushing through the Keys results in freshening breezes.

DISCUSSION

Issued at 510 AM EST Fri Dec 12 2025 A "chilly" night for those in the Florida Keys, as temperatures dropped into the mid 60s overnight with dew points in the lower 60s. Dry air dominating the region on MIMIC precipitable water, and confirmed on last night's 00z sounding, has kept any shower development from happening, therefore, KBYX has remained quiet. Along the Reef, winds are currently being observed at near 10 knots. A broad area of high pressure over the southeastern US and drifting into western Atlantic will dominate the present weather through the next few periods, leading to generally stable, mostly dry weather with light to gentle breezes and seasonal temperatures for the Keys.

As the weekend unfolds, a frontal boundary will move towards South Florida, increasing cloudiness and moisture and elevating the chance for showers and thunderstorms Saturday into Sunday. While no severe weather is expected at this time, SPC does have South Florida and the Keys highlighted for thunderstorms on their Day 2 and 3 Outlook (Saturday 12z-Monday 12z). Once this feature moves through, northerly to northeasterly breezes will strengthen behind it, bringing likely Small Craft Advisory conditions. We will also see slightly cooler air and diminishing shower chances as high pressure rebuilds later in the week.

MARINE

Issued at 510 AM EST Fri Dec 12 2025 No watches, warnings, or advisories are currently in effect for the Florida Keys waters. From synopsis, as high pressure drifts eastward into the western North Atlantic, winds as a result will be northeast to east. The next frontal boundary is progged to push through the Florida Keys marine zones on Sunday night. Ahead of the front, elevated chances for showers and thunderstorms will be possible late Saturday through early Sunday. In the wake of the frontal passage, fresh to strong northeasterly breezes are expected Sunday night through at least Tuesday.

AVIATION

(06Z TAFS) Issued at 510 AM EST Fri Dec 12 2025 VFR and dry conditions are expected to prevail at the terminals through the TAF period. Northeast winds of 5 to 10 knots are expected to persist through the period.

CLIMATE

On this day in 1957, the daily record low temperature of 42F was recorded at Marathon. Temperature records for Marathon date back to 1950.

KEY WATCHES/WARNINGS/ADVISORIES

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