textproduct: Key West

KEY MESSAGES

- Rain chances will remain slightly above normal for tonight, but any activity should be considerably weaker.

- Light to gentle northeast to east winds may briefly surge this evening then decrease early Tuesday morning. Expect periods of variability until light to gentle east to southeasterly breezes build in by mid week.

- Rain chances become slim to none by mid week, and continue through most of the remainder of the week.

MARINE

Issued at 358 PM EDT Mon May 4 2026

The coastal waters surrounding the Florida Keys remain in a chaotic state as a weak frontal boundary lingers nearby in the Straits of Florida. This is creating gentle northerly breezes across the nearshore waters and Southeast Gulf while light and variable winds are occurring across the Straits of Florida. Additional rounds of convection are possible this evening, especially across the Straits of Florida. The stronger showers and thunderstorms will be capable of strong gusty winds, locally higher seas, at times frequent lightning strikes, and blinding downpours. The active pattern will gradually calm down over the next 24 hours. Winds will then shift north to northeast as the boundary starts washing out across the Florida Straits. Winds will remain light and varying tomorrow into tomorrow night due to the lingering remnant boundary. By mid week the western flank of a broad Atlantic Ridge will move across Florida and establish a more normal light to gentle east to southeasterly flow.

AVIATION

(18Z TAFS) Issued at 358 PM EDT Mon May 4 2026

VFR conditions are expected through the evening and will only be interrupted by brief MVFR conditions from an occasional passing shower. Otherwise, northeast to east winds will become light and variable overnight and continue into Tuesday.

PREV DISCUSSION

Issued at 430 AM EDT Mon May 4 2026

A weakening frontal boundary is slowly working its way southward into the Florida Straits this morning. In response, light breezes along the island chain have finally shifted to the long expected northwesterly direction. This shift, along with convective outflows has lowered dew points in most locations to the a degree or two above 70. Temperatures now range from the upper 70s in the Lower Keys to the lower 70s in the Middle and Upper Keys. Meanwhile, a mid latitude trough over the eastern United States and a phasing shortwave trough moving across Florida has contributed to a good amount of diffluent flow aloft. After several rounds of showers and thunderstorms across the Forecast area, the strongest activity is now focused across the Florida Straits. With that said, a large swath of light to moderate rain continues to blanket the Middle and Upper Keys.

For today, precipitable water will remain near or slightly above the 90th percentile with nearly saturated lower levels and modest CAPE. The shortwave trough aloft will lift out into the Atlantic, leaving a broad synoptic trough that reaches into the northwestern Caribbean Sea. Rain and thunder activity will ease back considerably today due to the above and as the surface boundary creeps more fully into the Florida Straits turning further north. With that said, rain chances will remain above normal due to the lingering copious low level moisture, moderately unstable atmosphere, and weakening support, both aloft and through the lower levels. Temperatures will be near normal with dew points remaining in the lower 70s.

The mid latitude trough will push east of our area tonight, and a strengthening mid to upper level ridge will drive eastward into the Gulf of America on Tuesday. In addition, a surface Atlantic ridge will become better established across Florida tonight into Tuesday and slowly wash out the lingering troughing across the Florida Straits. Until then, light surface breezes will quite often be variable, then become prevailing light east to southeasterly by mid week. As this transition occurs, precipitable water will drop to slightly below normal with increasing lower level inhibition. Expect rain chances to fall out of the forecast by mid week. Temperatures will be near normal until the east to southeasterlies start bringing in warmer and more humid air. Temperatures will climb into the upper 80s for the high and upper 70s to near 80 for the low. Dew points will return to a muggy mid 70s.

PRELIMINARY POINT TEMPS/POPS

Key West 85 76 86 77 / 30 20 10 10 Marathon 84 76 85 78 / 30 40 10 10

KEY WATCHES/WARNINGS/ADVISORIES

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