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.

SHORT TERM FORECAST.

Tonight's forecast is interesting. The 00z evening sounding is very unstable. CAPE value was measured to be around 2200 J/kg, plenty of moisture in the low levels from the surface up to around 750 mb before drying out above 750 mb. Another moist layer can be seen between 450 mb to 350 mb. The wind profile is chaotic with southeast winds at 1000 ft to northeast at 3000 ft. The PWAT value measured remains quite juicy at 1.76 inches which is right near the 90th percentile for the date. Most of ingredients are available for the radar to remain decently active overnight. There is moisture, instability, and we have a source of lift being this boundary. The activity has struggled to become a thunderstorm all evening which could be attributed to the stout dry layer on the sounding between 700-500 mb. Therefore, showers remain likely with the outside chance that perhaps one of these cells is able to punch through to become a thunderstorm. No changes expected to the forecast this update.

MARINE

Issued at 1012 PM EDT Mon May 4 2026 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, the winds across the coastal waters surrounding the Florida Keys remain in a chaotic state as a weak frontal boundary lingers nearby in the Straits of Florida. Additional rounds of convection will continue overnight, especially across the nearshore waters north of the Island Chain. Winds are expected to shift north to northeast as the boundary starts washing out across the Florida Straits. Winds will return to 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

(00Z TAFS) Issued at 1012 PM EDT Mon May 4 2026 VFR conditions are mostly expected to prevail at both EYW and MTH terminals through the TAF period. Currently, a boundary remains to the northeast of both terminals which is spawning waxing and waning showers to the northeast of the Middle and Lower Keys. There are some indications that as this boundary continues to ever so slowly drift south southwestward that an isolated shower or thunderstorm could impact either terminal. The best chance time for this appears to be between 05/02z-05/10z. Any showers or storms will be capable of reducing CIGs and VIS to MVFR, with a low probability for IFR. The most likely cause of IFR would be VIS. Also, any activity will be capable of gusty winds in and around convection. Drier air moves in on Tuesday leading to decreasing rain chances.

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.