textproduct: Key West

DISCUSSION

Issued at 139 PM EDT Fri Oct 16 2026 Current water vapor imagery and CIMSS steering products depict a broad anticyclone centered to the northeast of the Bahamas and a mid to upper-level trough deepening over the Upper Midwest and Great Lakes region. Ahead of the trough, current surface analysis depicts a cold front extending southwest from a surface low over Quebec through the Ohio Valley and into the northwestern Gulf. This front will continue to surge southeastward through tomorrow as the trough reaches the Eastern Seaboard. We currently have isolated showers and an occasional thunderstorm in the Straits being generated by weak speed convergence in the southeasterly low-level flow. As the mid- level trough axis nudges into the Gulf tonight, synoptic scale lift will begin to arrive across our forecast area while the Atlantic ridge becomes dampened to the east. This will promote an increased coverage of showers and storms through the overnight hours into Saturday morning, particularly as energy associated with an inverted trough near the Yucatan is lifted northward. The cold front will move southeast through the Gulf tomorrow morning and should be knocking on our doorstep by tomorrow evening. All in all, the weekend looks like a mess of numerous to widespread showers and thunderstorms and rapidly freshening breezes by Saturday night as a strong pressure gradient builds in. It now appears likely that we will have moderate to fresh, occasionally strong, northeasterly breezes across the Florida Keys and surrounding waters from Saturday night through at least Monday. A Small Craft Advisory will likely be needed for all of the Florida Keys coastal waters.

By Monday, although the winds will stay elevated, latest model solutions suggest the front should stall in the Straits of Florida as mid to upper-level dry air advects south across the area. In addition, potential is increasing for the development of a strong nor'easter off the Carolina coast. It's uncertain exactly how long this feature will loiter next week, but combined with a building ridge axis centered near the Mississippi River, persistent mid-level northerly flow across the eastern Gulf and along the Florida Peninsula should help to force the frontal boundary and drier post- frontal airmass further south which will support decreased shower/storm activity across the forecast area by mid-week, at least for locations along and north of the Island Chain. If we're lucky, there could be a noticeable decrease in humidity as well.

MARINE

Issued at 139 PM EDT Fri Oct 16 2026 No watches, warnings, or advisories are in effect for the waters surrounding the Florida Keys. Gentle to moderate east- southeasterly breezes will continue this afternoon as the Atlantic high weakens. A strong cold front will begin to track southeast through the Gulf tonight through tomorrow morning. It will approach the Florida Keys waters Saturday evening promoting higher chances for showers and storms as well as rapidly freshening northeast breezes to moderate to fresh, occasionally strong, by Saturday night into Sunday. A Small Craft Advisory will likely be required for all of the Florida Keys waters by Sunday at the latest as hazardous seas develop. Rain chances are forecast to decrease by early next week as the front moves south of the area. However, winds will likely remain elevated behind the front due to a strong pressure gradient.

AVIATION

(18Z TAFS) Issued at 139 PM EDT Fri Oct 16 2026 VFR conditions will continue at both terminals through the afternoon. There are scattered showers and a thunderstorm or two south of the TAF sites which will begin to lift northward overnight. Introduced a PROB30 for TSRA at both sites from ~06-11Z as hi-res guidance suggests a strong signal for convection lifting northward from Cuba during that time. Increasing moisture and an approaching cold front will support further activity tomorrow, but confidence on impacts at the TAF sites for the end of this cycle is low.

PRELIMINARY POINT TEMPS/POPS

Key West 79 87 77 86 / 60 60 90 90 Marathon 80 86 78 85 / 50 50 80 90

KEY WATCHES/WARNINGS/ADVISORIES

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