textproduct: Key West

KEY MESSAGES

- Moisture will linger across the region through the start of the weekend, supporting slightly above normal rain and thunderstorm chances.

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

- Heat index values will range from 100-108 degrees daily with little relief from the muggy conditions overnight. Know the signs of heat stress, take frequent breaks, and stay hydrated.

AVIATION

(18Z TAFS) Issued at 125 PM EDT Fri Sep 11 2026 VFR conditions will prevail at both EYW and MTH through the TAF period. Scattered showers will continue to pop up throughout the coastal waters occasionally crossing over the island chain, therefore VCSH is included at both terminals. If direct impacts are expected TEMPOs will be included at that time. Near surface winds will be east to southeasterly at 5 to 10 knots.

PREVIOUS DISCUSSION

Issued at 400 AM EDT Fri Sep 11 2026 Surface through mid level Atlantic ridging stretches westward across Florida. The surface ridge is supporting gentle to moderate east to southeasterly breezes along the island chain this morning. Last evenings sounding indicated precipitable water above the 90th percentile at 2.33 inches. This has been the case recently due to a stubborn swath of elevated lower level moisture pervading the area. The lower levels were very moist, with minimal inhibition and ample CAPE. After clusters of shower and thunderstorms through the day and evening, activity has since all but dissipated. Some short lived low level drying and stabilizing was expected for this time period and may have contributed to the unusual lack of convection in recent hours.

Through the weekend and into next week the surface through mid level ridge will remain in control of our area. Surface winds will remain east southeasterly with moderate peaks overnight and light lulls during the day. The previously mentioned short lived drying and stabilizing is expected to be just that. Lower level moisture will recover today into tonight as another swath of elevated lower level moisture sweeps westward into our area. This will help to keep shower and thunder chances slightly above normal through the weekend. Expect near to slightly above normal conditions with highs near 90 and lows in the lower to mid 80s. Things will remain sticky with dew points in the upper 70s.

Through the first half of the week, deep layered ridging will amplify over the southeast and eastern United States while a sharp trough digs off the Atlantic Coast. At the surface the ridge will be reinforced by a robust ridge coming off the Atlantic coast and may pull freshening breezes northeast to easterly. While this may eventually lead to dew points dipping into the mid 70s, continued moisture rich lower levels, along with an accelerating confluent flow may result in a period or two of elevated rain chances. This would be around Tuesday. There is a lot of moving parts here and uncertainty is high.

MARINE

Issued at 1055 AM EDT Fri Sep 11 2026 No watches, warnings, or advisories are currently in effect in the Florida Keys waters. From synopsis, ridging across the southeastern United States and Florida will maintain mostly gentle east to southeasterly breezes over the next few days. Expect breezes to peak in the evening and overnight while lulling during the day. Low level moisture will remain abundant and keep convective potential slightly above normal. The ridge will be reinforced late in the forecast and may drive freshening northeast to easterly breezes.

KEY WATCHES/WARNINGS/ADVISORIES

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