textproduct: Key West

KEY MESSAGES

-Windy to breezy conditions will persist until tonight

-Warmer temperatures and increasing rain chances expected to return on Thursday. While the atmosphere will become drier on Friday, expect temperatures to remain above normal through the weekend. -The next frontal boundary could move across the Florida Keys early next week.

FORECAST

A series of clipper systems across the Great Lakes over the past few days weakened the high over the Carolinas, and the high will make its way out into the Atlantic by Thursday. The pressure gradient will weaken over the Keys, and breezy conditions are not expected for the end of the work week. Broad confluence in the low levels prompted a 30% chance of showers tonight and a slight chance on Thursday. Temperatures will remain above normal through the weekend. Highs in the lower 80s are possible on Saturday and Sunday. Dew points, sadly, may rebound to the lower 70s. Aloft, skies will dry out and shower chances are 10% at most through Monday.

Elsewhere in the country, the forecast will be much more complicated. While the clipper lows weakened the Carolina high, they paved the way for a very sharp longwave trough to dig into the central United States. This low will phase together with a slow moving shortwave located over New Mexico tomorrow to Friday. Thus, the environment sets up for a very broad, very amplified winter storm stretching from Texas to the Carolinas. How exactly does this relate to Florida Keys weather? This winter storm will be able to form coastal lows, and statistical models suggest a coastal low could develop off the North Carolina outer bank. In this event, arctic air could be directed south towards the Keys. A cold front associated with this system is progged to move across the island chain sometime early next week. The most recent model guidance suggests frontal passage next Monday to Tuesday, but the timing and magnitude will change given newer data. Keep an eye on the forecast and to the north, because the upcoming winter system is going to be dramatic.

MARINE

Issued at 415 AM EST Wed Jan 21 2026 A Small Craft Advisory remains in effect for all Florida Keys marine zones. From synopsis, a broad high pressure system located over the Carolinas will slowly weaken as it slides into the western Atlantic during the work week. Breezes will slacken as the pressure gradient diminishes, and gentle to moderate breezes are expected across the nearshore and offshore waters by Thursday. Weekend conditions are more uncertain because a sequence of strong low pressure systems over the southeastern United States. A col region could form over the Keys on Sunday and support light to gentle breezes, or the Keys could be stuck under gentle to moderate northwesterlies.

AVIATION

(06Z TAFS) Issued at 415 AM EST Wed Jan 21 2026 There is increasing potential for MVFR ceilings at both island terminals this morning. Bases are expected to be between 2000 and 3000 ft. There will be a slight chance for showers, bringing with them spells of sub VFR visibility. Gentle to moderate northeasterly breezes early this morning are expected to become moderate to fresh after sunrise.

PRELIMINARY POINT TEMPS/POPS

Key West 75 69 78 70 / 10 20 20 20 Marathon 75 69 78 68 / 10 30 30 20

KEY WATCHES/WARNINGS/ADVISORIES

FL...None. GM...Small Craft Advisory until 11 AM EST this morning for GMZ031>035- 042>044-052>055-072>075.