Marine Forecast GMZ005

Expires:202608182100;;928302
FZUS52 KKEY 180859
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
459 AM EDT Tue Aug 18 2026

Florida Bay, Hawk Channel and Straits of Florida from Ocean Reef
to south of Dry Tortugas, and the extreme southeastern Gulf of
America, including The Florida Keys National Marine Sanctuary

Seas are given as significant wave height, which is the average
height of the highest 1/3 of the waves. Individual waves may be
more than twice the significant wave height.

The Wave Detail section highlights the period and direction of
origin for the highest-energy waves, as well as any long-period
swells moving in a different direction than the wind.


GMZ005-182100
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
459 AM EDT Tue Aug 18 2026

SYNOPSIS


An atlantic ridge axis draped across the coastal waters of the
Florida Keys will maintain a mostly variable wind pattern this
week with wind speeds mainly less than 10 knots. However, brief
increases in wind speeds may occur at times in the evening hours
with winds occasionally approaching 15 knots at times, mostly in
the Upper Keys, so exercise cautionary conditions could briefly
occur. In addition, the presence of saharan air across the Florida
Keys will keep near zero rain chances through the middle of the
week with a very small increase in rain chances by the end of the
week as moisture slowly recovers. The best rain chances late in
the week will typically occur north of the Island Chain in the Bay
and Gulf side waters, though any precipitation activity in
general is expected to be isolated to scattered in nature.

The Approximate Shoreward Edge of the Gulf Stream as of August
13, 2026

38 NM South of Dry Tortugas Lighton Loggerhead Key.
20 NM South of Cosgrove Shoal Lightoff the Marquesas Keys.
17 NM South of Sand Key Lightoff Key West.
21 NM South of Looe Keyoff Big Pine Key.
18 NM Southeast of Sombrero Key Lightoff Marathon.
7 NM Southeast of Alligator Reef Lightoff Islamorada.
7 NM Southeast of Molasses Reef Lightoff Key Largo.
2 NM Southeast of Carysfort Reef Lightoff Ocean Reef.

Gulf Stream Information Courtesy of the National Weather Service in
Key West, using data from RTOFS and NASA SPoRT SST.




All Gulf of Mexico Marine Forecast

Gulf of Mexico Marine Watches, Warnings and Advisories Check all Gulf of Mexico Marine Zones.