textproduct: Key West

KEY MESSAGES

- Well above normal rain chances (around 60-70%) will persist across the Florida Keys through the weekend and possibly into early next week.

- Heavy rainfall is expected at times. There is a marginal risk for excessive rainfall through the middle of next week.

- While breezes will be light to gentle (5 to 10 mph) throughout the weekend, gusty winds and locally hazardous seas are expected in the vicinity of thunderstorms.

SHORT TERM FORECAST

The 00z evening sounding unsurprisingly shows a very saturated and unstable profile through the atmospheric column. The PWAT value measured was 2.21 inches which is above the 90th percentile for the date. Suffice to say, it is wet out there. CAPE values remain modest between 1500-2000 J/kg, though, still plenty to support showers and thunderstorms. However, current thinking is the atmosphere is worked over for the time being. Therefore, it will take some time for the atmosphere to reload before the next round of potential convection which appears to be early morning through the early to mid afternoon on Saturday. Overall, current thinking is that much of the overnight should remain dry outside of a stray shower or potential thunderstorm.

MARINE

Issued at 1002 PM EDT Fri Sep 18 2026 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, light to gentle breezes will continue through the weekend. In addition, an increasingly wet weather pattern will develop across the Florida Keys coastal waters through early next week, as an upper-level low retrogrades westward across the Florida Peninsula and eventually slides into the Gulf this weekend. As a result, scattered to occasional numerous showers and thunderstorms will be a daily occurence, with gusty winds, lightning strikes, blinding downpours, and locally hazardous seas being the main hazards mariners could encounter in the vicinity of this activity. The upper-level low is forecast to move out of the area early next week, with winds becoming more southerly and breezes remaining light to gentle. Rain chances will also continue to remain elevated into next week, as deep moisture lingers across the Florida Keys coastal waters in the wake of the departing weather disturbance.

AVIATION

(00Z TAFS) Issued at 1002 PM EDT Fri Sep 18 2026 VFR conditions will persist at both EYW and MTH terminals through the TAF period. However, the wet pattern remains in place with rounds of showers and thunderstorms expected to continue. Residual shower activity this evening is expected to continue to wane with much of the overnight remaining dry. Then, towards daybreak, showers and thunderstorms are expected to reignite across the Florida Keys, potentially between 19/09-12z with most of this activity waning by early to mid afternoon (19/17-19z). Any showers and thunderstorms will be capable of gusty winds, cloud to ground lightning, MVFR conditions for VIS and CIGs with the potential for IFR, even the low probability for brief LIFR conditions. Another lull is anticipated Saturday afternoon and evening, though, a stray shower or storm cannot be ruled out. Since we have decent confidence in the forecast, VCSH was included in the TAFs.

PRELIMINARY POINT TEMPS/POPS

Key West 90 80 90 79 / 50 60 60 60 Marathon 89 80 88 80 / 60 60 60 60

KEY WATCHES/WARNINGS/ADVISORIES

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