textproduct: Key West

KEY MESSAGES

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

- Light to gentle east to southeast winds are expected to back to the north to northeast towards daybreak, though, variability to the winds remains.

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

DISCUSSION

Issued at 400 AM EDT Tue May 5 2026

A poorly defined surface trough that runs from off South Florida's Atlantic coast and through the Florida Straits is keeping light and variable breezes across the area. Broad troughing remains aloft with the synoptic trough extending down into the northwestern Caribbean Sea. The troughs axis is now located over the Bahamas and continuing to swing out to sea. Enhanced lower level convergence associated with this trough and preexisting boundaries, are supporting a broken band of showers and an isolated embedded thunderstorm, aligned roughly parallel to the island chain. This is despite dry layers showing up through the mid levels. Despite the weak and disorganized surface flow, the lower level flow is has a surprisingly healthy veering profile and has contributed to occasionally rotating cells. Surface temperatures are slightly above normal with dew points stubbornly holding in the lower to mid 70s.

Robust mid to upper level ridging will amplify over the next couple of days as it drives eastward through the Gulf. This will result in rising mid level heights and considerable drying through the column. As a result, a few showers this morning should give way to rain free weather by tonight. Winds will remain light and often variable today into tonight as the weak trough slowly dissipates and ridging begins building southwestward across Florida. With nothing to kick out the in-situ airmass, expect temperatures to largely remain slightly above normal with highs in the upper 80s and lows in the upper 70s.

The mid to upper level ridge will continue to push eastward and be aligned across Cuba on Thursday and flatten as it transitions into the Atlantic. Precipitable water will fall to slightly below normal with a nose of low level inhibition strengthening. As a result, rain chances will remain out of the forecast through the remainder of the work week. At the same time, Atlantic surface ridging will broaden as it becomes better established across South Florida. In response, winds will become light to gentle southeasterlies. This flow will bring in warmer and more humid air. Expect highs in the upper 80s, overnight lows struggling to fall below 80, and dew points climbing into the muggy mid 70s range.

Uncertainty is fairly high heading into the weekend. A new shortwave trough will begin swinging eastward through eastern United States, flattening the upper level ridge. The lower level ridge will be pinched southeastward across Cuba and the Bahamas and setup a moistening and increasingly confluent flow. Meanwhile the surface ridge will expand northward and help to bring in freshening southeasterlies. Altogether, this will open the door to isolated to possibly scattered showers. Day time highs may slip a degree or two while overnight lows will be near or slightly above 80.

MARINE

Issued at 400 AM EDT Tue May 5 2026

Weak surface troughing stretching southwestward from the Atlantic waters off of South Florida to the Florida Straits. This will result in considerable uncertainty in wind direction. In general, light to gentle northeasterly breezes will shift northwest through the day. Isolated showers will remain possible, but gradually, drying through the lower levels associated with increasing ridging will help to end shower chances. Winds will tend light and variable tonight into Wednesday, but light to gentle east to southeasterlies should take and remain through the work week. While uncertainty is high, there are hints that an Atlantic ridge across our area will shift slightly northward and bring in gentle to moderate southeasterly breezes. This is not yet fully incorporated into the forecast.

AVIATION

(00Z TAFS) Issued at 400 AM EDT Tue May 5 2026

VFR conditions will prevail at the island terminals today. However, this morning there will be a slight chance for showers, accompanied by sub VFR ceilings and visibility. Surface winds may be quite varying, but tend light northeasterly this morning, shifting northwest through the day.

KEY WATCHES/WARNINGS/ADVISORIES

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