textproduct: Key West

KEY MESSAGES

-Showers close to the island chain will diminish today as drier air settles in.

-Small Craft Advisories remain in effect for fresh to strong northeast to east breezes.

-As high pressure builds in over the second half of the week, mild, mostly dry conditions will be expected with gentle to moderate breezes.

DISCUSSION

Issued at 512 AM EST Tue Dec 16 2025 The KBYX radar has been busy tracking scattered showers across the Straits of Florida during the overnight shift. Earlier this evening, a few lighter showers skirted across portions of the Middle and Upper Keys. The automated observation site at Marathon International Airport reported a trace of rain just before 10 PM, but MRMS suggests up to a tenth of an inch fell along some island communities. The periphery of this activity is only a few miles offshore of the Middle Keys, but it is slowly pulling away. Breezy conditions have continued through the night as well with land observations reporting frequent gusts near 25 mph, and marine platforms reporting gusts closer to 30 mph (or near 27 knots).

Drier air at the surface has been slow to filter in behind the front that went through yesterday, and this has played a key role in the lingering showers. However, dew points 24 hours ago were in the lower 70s whereas now they are in the upper 60s. While not substantial, it does indicate that the drier air is finally filtering in at the surface. We will go ahead and carry a slight chance (10%) of rain for the island chain to account for the light showers nearby, but the drier air finally moving in near the surface will help to bring these chances to near zero by the afternoon.

Mean layer ridging will build in over the next couple of days as the current troughing lifts away. Breezes will slacken, and temperatures will trend upward a few degrees. Global models continue to hint at another front passing through either on Friday or Saturday, but what there is a fair amount of disagreement among guidance as to what our sensible weather will look like. Global ensembles are showing some rainfall across the area courtesy of deepening moisture, but the NBM has shown some flip flopping between single digit and slight chance PoPs. What this does tell us is that we are dealing with a progressive pattern, so the calmer weather that we see over the midweek wont have the opportunity to take up residence along the Florida Keys, and change will come down the pipeline eventually. Its just a matter of when the change comes, and that should become clearer over the next day or two.

MARINE

Issued at 512 AM EST Tue Dec 16 2025 A Small Craft Advisory remains in effect for all Florida Keys local waters. From synopsis, in the wake of the recent cold front passage, fresh to strong breezes will continue for at least another day. As an area of high pressure slides into the central North Atlantic by Wednesday night, breezes will slacken for the second half of the week. A second, weaker front will push through the Florida Keys coastal waters by the end of the week, with modestly freshened breezes expected for the weekend behind the front.

AVIATION

(06Z TAFS) Issued at 512 AM EST Tue Dec 16 2025 VFR conditions will prevail at both EYW and MTH today. While a stray shower cannot be ruled out, low coverage of possible showers near the island chain will keep mention out of either TAF for now. Near surface winds will be generally out of the northeast at 10 to 15 knots with frequent gusts to 20 to 25 knots gradually decreasing throughout the day.

CLIMATE

On this day in 1968, the daily record cold high temperature of 60F was last recorded in Key West. Temperature data for Key West dates back to 1872.

PRELIMINARY POINT TEMPS/POPS

Key West 78 70 80 72 / 10 10 10 10 Marathon 76 70 79 72 / 10 0 10 10

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...Small Craft Advisory until 5 PM EST this afternoon for GMZ031>035-042>044-052>055-072>075.