textproduct: Key West

KEY MESSAGES

-A front remains over the Keys bringing isolated thunderstorms and high rain chances. Peak rain chances are expected from now through the 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.

SHORT TERM FORECAST

An interesting setup for the Keys continuing through the overnight hours. One upper level shortwave continues to traverse through the Keys this evening which is responsible for the rain that is still ongoing across the area. A second upper level shortwave is approaching from the west this evening. This one is responsible for the secondary area of showers and thunderstorms moving into the Keys coverage area from the Gulf. At the surface, high pressure remains the more dominant feature with a weak surface reflection to the northwest of the western tip of Cuba. For the overnight, we expect light to moderate rain to continue for the Island Chain with any thunderstorm activity waning across the Straits over the next few hours. However, any lull is expected to be fairly brief as we expect this secondary area to move through during the overnight and clearing the Keys mostly before daybreak Sunday. The 00z evening sounding also came in quite saturated with the exception of two dry layers. One dry layer was measured between 900-850 mb with the second from 775 to 650 mb. The PWAT value measured was 1.93 inches which is not too far from the MAX value for the date of 2.03 inches. All in all, we have the upper level support, moisture, and instability. Therefore, an active night is expected to continue, though, it is not expected to be to the extent it was late this afternoon and evening. Finally, no changes anticipated with this update.

MARINE

Issued at 1036 PM EST Sat Dec 13 2025 Small Craft Should Exercise Caution (SCEC) until winds decrease is headlined for the Straits of Florida and Hawk Channel. From synopsis, moderate to fresh breezes south of the Chain and gentle to moderate breezes north of the Chain will gradually slacken overnight ahead of the next frontal passage. The next front is progged to push through the Florida Keys marine zones Sunday evening. Ahead of the front, elevated chances for showers and thunderstorms will be possible tonight through early Sunday. In the wake of the frontal passage, fresh to strong northeasterly breezes are expected Sunday night through at least Tuesday. Breezes slacken starting Wednesday but will remain gentle to moderate at times.

AVIATION

(00Z TAFS) Issued at 1036 PM EST Sat Dec 13 2025 VFR conditions are largely expected to prevail at both terminals through the TAF period. However, periodic episodes of MVFR CIGs and potentially VIS are possible through the overnight hours. Current radar trends show the rain starting to lull for EYW with MTH over the next few hours. There are more showers across the Gulf just outside the Keys that may encroach on the terminals during the overnight. Latest guidance shows the rain mostly ending around 14/09z, though, we cannot still rule out a passing shower afterwards. Near surface winds should remain east to southeast between 6 to 12 knots with occasional gusts to near 20 knots for the next few to several hours before shifting to the northwest to north by late Sunday as a front approaches.

PRELIMINARY POINT TEMPS/POPS

Key West 81 71 80 67 / 60 80 40 20 Marathon 79 71 78 67 / 50 80 50 20

KEY WATCHES/WARNINGS/ADVISORIES

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