textproduct: Key West

KEY MESSAGES

- Breezy conditions will return Monday, with an extended period of windy conditions for much of the remainder of the work week.

- Small Craft Advisories will likely be required for portions or all of the Keys coastal waters as early as Monday night.

- Rain chances will be well above normal for Tuesday night through Wednesday night.

DISCUSSION

Issued at 1215 PM EST Sun Nov 15 2026 Upper-level geopotential height analysis continues to depict an amplified synoptic pattern across the CONUS. A pronounced ridge bridges across the west coast, with a well-defined subtropical jet extending across the Gulf Coast eastward into the western North Atlantic. At the surface, a strong high pressure system is currently centered over the upper Mississippi Valley, with associated anticyclonic flow supporting north to northeast breezes across the Florida Keys at this early afternoon hour. The resulting cool advection has limited meaningful temperature rebounds thus far on this Sunday, with land-based surface observations sampling temperatures in the lower 70s, well below what most available numerical weather prediction guidance suggested for today. KBYX radar is void of any meteorological echo returns.

Over the next twenty-four hours, the surface high will slowly migrate eastward and amplify, supporting freshening breezes that will clock around to the northeast to east. The subtle directional change will help to modify temperatures closer to near normal, with dew points also rebounding. A weak shortwave trough currently over the southern Great Plains will slide eastward over the next several days. Global ensemble guidance supports falling heights in the vicinity of the Florida Keys, with the Island Chain in a region of upper level divergence Tuesday night through at least Wednesday night. Coupled with a decent veering profile along with ample moisture below 800 mb in forecast soundings support well above normal rain chances for these periods. While thunderstorms cannot be ruled out, the environment will be limited in terms of potential instability, so maintaining just slight thunder probs for now.

There is quite a bit of uncertainty regarding the forecast beyond Wednesday night. Much of this uncertainty stems from the ultimate evolution of the shortwave trough. If the trough festers in the vicinity of the Gulf, weak surface cyclogenesis may occur, supporting continued wet conditions for much of the remainder of the work week. Conversely, if the trough can pivot eastward into the western Atlantic, this would push drier air towards the Keys. With both solutions seeming viable, will maintain slightly above normal rain chances beyond Wednesday night, meanwhile emphasizing the low confidence forecast. Regardless of this ultimate evolution, breezy to windy conditions appear to continue through at least the end of the work week, and possibly into the weekend.

MARINE

Issued at 1215 PM EST Sun Nov 15 2026 A high pressure system centered in the Upper Mississippi River Valley will slide to the southeast over the next several days and strengthen. This will tighten the pressure gradient across the Florida Keys coastal waters, with breezes freshening beginning tonight. Fresh to strong breezes will prevail for much of the work week, with elevated rain chances Tuesday night through at least Wednesday night.

AVIATION

(18Z TAFS) Issued at 1215 PM EST Sun Nov 15 2026 VFR conditions will prevail at both island terminals through 18z Monday afternoon. While speed convergence driven isolated showers cannot be ruled out lack of coverage and impacts to visibilities keeps mention of them out of the TAFs at this time. Surface north to northeast winds will veer to the northeast to east overnight, with gusts 17 to 20 knots becoming more frequent.

PRELIMINARY POINT TEMPS/POPS

Key West 76 74 80 74 / 0 10 10 10 Marathon 76 74 80 74 / 0 10 10 20

KEY WATCHES/WARNINGS/ADVISORIES

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