textproduct: Key West

KEY MESSAGES

- Saltwater to major saltwater flooding of low elevation streets and lots is likely through this week due to a potent King Tide. Don't drive through flooded roadways. Boaters can expect less clearance under fixed bridges.

- A Coastal Flood Advisory is in effect for the Lower to Middle Keys, and a Coastal Flood Warning is in effect for the Upper Keys.

- Northeasterly swell from a Nor'easter off the East Coast will continue to produce 2 to 4 foot seas through the overnight in the eastern Straits of Florida.

SHORT TERM FORECAST

The 00z evening sounding continues to remain quite dry. However, moisture is beginning to grow in the lower levels with a moist layer from approximately 900 to 800 mb. The PWAT value measured was 1.34 inches which is right at the 10th percentile for the date. The wind profile is mostly unidirectional out of the west at near 10 knots. Overall, no forecast changes are expected this update and shower activity, if any, is mainly expected to remain across the marine area, especially south of the Chain.

MARINE

Issued at 1027 PM EDT Sun Sep 27 2026 There are currently no watches, warnings, or advisories in effect across the Florida Keys coastal waters. From synopsis, a Nor'easter in the vicinity of New Jersey which will continue to support a northeasterly swell with large periods in the eastern marine zones through overnight, before subsiding tomorrow. A weak frontal boundary will begin to push back northward through the marine zones on Monday. Winds will then clock back to the southeast to south for early this week, also accompanied by increasing rain and thunder chances. In addition, strengthening high pressure is expected to move off the Southeast U.S. coastline around the middle to latter half of next week, merging with the Atlantic high. This will promote freshening east to southeast breezes, potentially become moderate to fresh.

AVIATION

(00Z TAFS) Issued at 1027 PM EDT Sun Sep 27 2026 VFR conditions will persist at both EYW and MTH terminals through the TAF period. Near surface winds will remain west to northwest overnight, shifting to the southwest to west Monday morning before further shifting to the south to southwest Monday afternoon and evening. Near nil rain chances are expected through the TAF period, though, there is a very low risk for a passing shower sometime Monday afternoon or evening that could affect either terminal.

PRELIMINARY POINT TEMPS/POPS

Key West 87 77 88 77 / 10 10 30 60 Marathon 85 78 86 78 / 10 10 20 60

KEY WATCHES/WARNINGS/ADVISORIES

FL...Coastal Flood Warning until 6 AM EDT Monday for FLZ076.

Coastal Flood Advisory until 6 AM EDT Monday for FLZ077-078.

GM...None.