textproduct: Key West

KEY MESSAGES

-A front will push through the Keys tonight bringing isolated thunderstorms and high rain chances peaking overnight before tapering off Sunday morning.

-Drying and freshening breezy conditions expected Sunday night into Monday, with post-frontal winds reaching Small Craft Advisory levels Monday and persisting through early Tuesday.

-As high pressure builds over the region mid-week, mild, mostly dry conditions will be expected with gentle to moderate breezes.

MARINE

Issued at 107 PM EST Sat Dec 13 2025

Showers and thunderstorms remain prolific across the western half of the Straits of Florida, especially near and southwest of Wood's Wall Crack. As the afternoon progresses and we go into the overnight, expected coverage to expand towards the north and east. Showers are expected to become more numerous with additional scattered thunderstorms. Main hazards will be the potential for gusty winds, locally rough and confused seas, occasional lightning strikes, and potentially blinding downpours. Outside of any convection, expect moderate to fresh breezes across the waters south of the island chain to briefly slacken on Sunday ahead of the next front. Expecting a frontal passage from the northwest starting in the afternoon across the outer Gulf waters and overtaking the remaining coastal waters towards sunset Sunday. In the wake of the frontal passage, breezes will sharply freshen with a period of fresh to occasionally strong breezes possibly lingering into Tuesday. Breezes, thereafter, will slacken but will remain generally gentle to moderate.

AVIATION

(18Z TAFS) Issued at 107 PM EST Sat Dec 13 2025

Precipitation continues to slowly drift northward this afternoon but has thus far stayed just outside of 10 nm of the EYW terminal. Chances for showers and thunderstorms will be increasing this afternoon for both island terminals, peaking this evening. Have introduced VCSH to both EYW and MTH with a tempo for TS at EYW around sunset. This may need to be adjusted sooner and will be handled with amendments if needed. Outside of any convection, winds will generally be east through the forecast period, but expect a backing to the northwest Sunday afternoon as the next cold front approaches.

PREV DISCUSSION

Issued at 427 AM EST Sat Dec 13 2025 This morning, temperatures across the Florida Keys are near 70F, with dew points in the mid 60s. Winds along the Reef are generally from the northeast to east at 15 to 20 knots, driven by high pressure in the western Atlantic and lower pressure to the west. This gradient is strongest over the water currently accounting for these slightly elevated winds along the Reef and offshore. Skies are mostly cloudy with upper-level clouds being observed on Nighttime Microphysics imagery, while lower-level clouds remain limited. KBYX radar shows a few light showers in the distant Straits, though the island chain has remained generally rain-free overnight.

Moderate to fresh breezes are expected to start to slacken this morning, therefore the headline "Small Craft Exercise Caution Until Winds Decrease" is in place for the Hawk Channel and Straits of Florida until those winds come down early afternoon. Later in the day, a shortwave trough advancing across the western Gulf waters will drive a front through the Keys. Pre-frontal moisture advection will result in numerous showers and isolated to scattered thunderstorms with rain chances peaking tonight at 80%. As the front moves through, shower activity will diminish starting late Sunday morning rapidly drying out by Sunday night and Monday. Post- frontal winds will increase to Small Craft Advisory levels Monday through possibly Tuesday morning while the pressure gradient behind the front tightens. Mid-week, another area of high pressure will build across the region, resulting in generally uneventful weather. Shower chances will be minimal (~10%) with gentle to moderate breezes.

KEY WATCHES/WARNINGS/ADVISORIES

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