textproduct: Key West

KEY MESSAGES

- Moisture will linger across the region through midweek, supporting rain and thunderstorm chances.

- The primary threat for any stronger thunderstorms will be dangerous lightning strikes. When thunder roars, go indoors. If on a boat, stay low, or go below.

- Heat index values will range from 100-105 degrees daily, with little relief in the muggy conditions overnight. Know the signs of heat stress, take frequent breaks, and stay hydrated.

DISCUSSION

Issued at 940 PM EDT Mon Sep 7 2026

Latest surface analysis reveals an east to west oriented surface front draped across Central Florida and into the eastern Gulf. This is associated with a mid to upper-level longwave trough which is shifting east from Canada into the North Atlantic waters. CIMSS mean layer wind products show the far southern periphery of this trough remains extended across Florida and into the eastern Gulf, flanked on both sides by persistent deep-layer ridging. GOES-E vorticity products show a column of positive vorticity advecting south across Florida and the surrounding Gulf and Atlantic waters. This will combine with abundant atmospheric moisture (2.28" PWATs measured on the 00Z KKEY RAOB) to support chances for scattered showers and thunderstorms across the area tonight through tomorrow. Although we're in a bit of a lull currently, hi-res guidance indicates a resurgence in activity by the early morning hours. As the parent trough pulls further away during the day tomorrow, weak height rises are forecast to occur as deep-layer ridging begins to recover its grasp over the region. We'll have another hot day with light and variable winds, highs near 90s degrees, and dewpoints in the upper 70s all contributing to feels like temperatures ranging from 100-105 degrees.

MARINE

Issued at 940 PM EDT Mon Sep 7 2026

No watches, warnings, or advisories are currently in effect for the Florida Keys waters. From synopsis, the Florida Keys and surrounding coastal waters will be in a broad nebulous pressure pattern. This will lead to light and at times variable breezes through early Wednesday. During the day on Wednesday, the western extent of the Atlantic Ridge will build in, allowing breezes to become more easterly and freshen to gentle to moderate. Waves of low-level moisture pushing across the Keys will support elevated rain and thunder chances through Tuesday, possibly returning to near normal by mid week.

AVIATION

(00Z TAFS) Issued at 735 PM EDT Mon Sep 7 2026

VFR conditions are expected to prevail at both TAF sites through much of this cycle. VCSH will continue to dwindle near KEYW over the next couple of hours. Winds will be light and VRB through the overnight hours. Moist atmospheric conditions combined with weak troughing across the region will promote renewed showers and storms across the area tomorrow. Persistence has shown that KEYW and areas near the Lower Keys has experienced most of the activity, so a PROB30 for TSRA was included for 11-15Z.

KEY WATCHES/WARNINGS/ADVISORIES

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