textproduct: Key West

KEY MESSAGES

-Fresh northeast to east breezes and well-developed seas will continue to support Small Craft Advisories for the Straits of Florida overnight.

-A mild and mainly dry pattern is expected to continue through Christmas Day with slightly above normal temperatures and seasonable humidity levels.

-The next, potentially strong cold front is progged to push through the Florida Keys early next week.

DISCUSSION

Issued at 1015 PM EST Wed Dec 24 2025 The main story across the CONUS is the high amplitude ridge extending from Central America to the Canadian Prairies. A rich plume of moisture on its western flank continues to hammer California with flooding rains and feet of snow in the higher elevations. Closer to home, surface observations place a high pressure system in the northeastern Gulf of America. Northeast to east winds average 15 to 18 knots at the Reef, with magnitudes a few knots less in Florida Bay and the Gulf side waters. The 00Z KKEY RAOB sampled a dry and stable profile. The lack of showers on the KBYX radar are not surprising. The forecast calls for overnight lows near 70 and a little less breeze than last night. No changes are needed for the inherited forecast.

DISCUSSION

Issued at 953 AM EST Wed Dec 24 2025 Composite tropospheric geopotential height and surface pressure field analysis depicts a very amplified, relatively stagnant pattern across the CONUS. The pattern is consistent with an omega blocking pattern, with a longwave trough over the Pacific Coast and a second trough in the west-central North Atlantic. This places most of the United States (including the Florida Keys) under the influence of an anomalously strong ridge sandwiched between the troughs. At the surface, a developing area of low pressure continues to progress along the aforementioned North Atlantic trough aloft, with anticyclonic flow associated surface high pressure system centered east of Bermuda providing moderate to fresh northeast to east breezes for the Keys. GOES-19 visible satellite imagery is depicting mostly clear to partly cloudy skies across the marine zones adjacent to the Island Chain, with land- based surface observations sampling temperatures generally in the mid 70s at this late morning hour of Christmas Eve.

For the balance of today, as the high continues to slide eastward and weaken, gradient winds will slowly respond and gradually decrease. The 12z morning sounding at KEY sampled decaying boundary layer moisture relative to the past 24-48 hours. Coupled with a more unidirectional boundary layer wind vector with height, rain chances will be near-nil for the rest of today. Highs today will reach the upper 70s to near 80F, depending on how easterly the winds veer later this afternoon. Outside of modest uptick in winds early in the forecast period based on the latest available marine observations, no changes proposed for this update cycle.

MARINE

Issued at 1015 PM EST Wed Dec 24 2025 Small Craft Advisory remains in effect for the Straits of Florida due to satellite derived wind estimates near 20 knots. From synopsis, high pressure centered over the northeastern Gulf of Mexico supports moderate to fresh northeast to east breezes across the Florida Keys this evening. The high will weaken as it continues to drift slowly southeastward through the weekend, leading to slackening breezes. A potentially strong cold front is progged to push through the Florida Keys coastal waters early next week, with freshening northerly breezes and building seas expected in its wake.

AVIATION

(00Z TAFS) Issued at 1015 PM EST Wed Dec 24 2025 VFR and gentle northeast breezes will prevail at the EYW and MTH terminals overnight.

PRELIMINARY POINT TEMPS/POPS

Key West 69 78 69 78 / 0 0 0 0 Marathon 69 76 69 77 / 0 0 0 0

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...Small Craft Advisory until 5 AM EST Thursday for GMZ052>055- 072>075.