Coastal Waters Forecast
Issued by NWS Key West, FL
Issued by NWS Key West, FL
540 FZUS52 KKEY 040832 CWFKEY Coastal Waters Forecast for the Florida Keys National Weather Service Key West FL 432 AM EDT Fri Sep 4 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. GMZ005-042045- Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas 432 AM EDT Fri Sep 4 2026 .SYNOPSIS... The western periphery of a weak North Atlantic high will remain in loose control of the Keys coastal waters for the next few days. Light to gentle, occasionally moderate, east to southeast breezes overnight through morning will become light and variable at times during the afternoon and evenings. In addition, the overall flow will keep low-level moisture in place across the region, with seasonally normal rain and thunder chances. The Approximate Shoreward Edge of the Gulf Stream as of September 2, 2026... 34 NM south-southwest of Dry Tortugas Light, on Loggerhead Key 34 NM south-southeast of Cosgrove Shoal Light, off the Marquesas Keys 26 NM south-southeast of Sand Key Light, off Key West 21 NM south-southeast of Looe Key, off Big Pine Key 17 NM southeast of Sombrero Key Light, off Marathon 10 NM southeast of Alligator Reef Light, off Islamorada 6 NM east-southeast of Molasses Reef Light, off Key Largo 1 NM east-southeast of Carysfort Reef Light, off Ocean Reef This data courtesy of the Naval Oceanographic Office. $$ GMZ031-042045- Florida Bay including Barnes Sound, Blackwater Sound, and Buttonwood Sound- 432 AM EDT Fri Sep 4 2026 .TODAY...Southeast to south winds 5 to 10 knots. Bay waters smooth to a light chop. A chance of showers and thunderstorms. .TONIGHT...East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop. A chance of showers and thunderstorms. .SATURDAY...Southeast winds 5 to 10 knots. Bay waters smooth to a light chop. A chance of showers and thunderstorms. .SATURDAY NIGHT...East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop. A chance of showers and thunderstorms. .SUNDAY...South winds near 5 knots. Bay waters smooth. A chance of showers and thunderstorms. .SUNDAY NIGHT...South winds near 5 knots. Bay waters smooth. A chance of showers and thunderstorms. .MONDAY...South to southwest winds near 5 knots. Bay waters smooth. Showers and thunderstorms likely. .MONDAY NIGHT...Southeast to south winds near 5 knots. Bay waters smooth. A chance of showers and thunderstorms. .TUESDAY...Southeast winds near 5 knots. Bay waters smooth. A chance of showers and thunderstorms. .TUESDAY NIGHT...East winds 5 to 10 knots. Bay waters smooth to a light chop. A chance of showers and thunderstorms. $$ GMZ032-035-042045- Bayside and Gulfside from Craig Key to west end of Seven Mile Bridge- Gulf of America from west end of Seven Mile Bridge to Halfmoon Shoal out to 5 Fathoms- 432 AM EDT Fri Sep 4 2026 .TODAY...Southeast winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop. A chance of showers and thunderstorms. .TONIGHT...East to southeast winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop. A chance of showers and thunderstorms. .SATURDAY...Southeast winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop. A chance of showers and thunderstorms. .SATURDAY NIGHT...East to southeast winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop. A chance of showers and thunderstorms. .SUNDAY...South winds near 5 knots. Seas 1 foot or less. Nearshore waters smooth. A chance of showers and thunderstorms. .SUNDAY NIGHT...Southeast to south winds near 5 knots. Seas 1 foot or less. Nearshore waters smooth. A chance of showers and thunderstorms. .MONDAY...South to southwest winds near 5 knots. Seas 1 foot or less. Nearshore waters smooth. A chance of showers and thunderstorms. .MONDAY NIGHT...Southeast to south winds near 5 knots. Seas 1 foot or less. Nearshore waters smooth. A chance of showers and thunderstorms. .TUESDAY...Southeast winds near 5 knots. Seas 1 foot or less. Nearshore waters smooth. A chance of showers and thunderstorms. .TUESDAY NIGHT...East winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop. A chance of showers and thunderstorms. $$ GMZ042>044-042045- Hawk Channel from Ocean Reef to Craig Key out to the reef- Hawk Channel from Craig Key to west end of Seven Mile Bridge out to the reef- Hawk Channel from west end of Seven Mile Bridge to Halfmoon Shoal out to the reef- 432 AM EDT Fri Sep 4 2026 .TODAY...Southeast winds 5 to 10 knots. Seas around 1 foot. Nearshore waters smooth to a light chop. A chance of showers and thunderstorms. .TONIGHT...East to southeast winds 5 to 10 knots. Seas around 1 foot. Nearshore waters smooth to a light chop. A chance of showers and thunderstorms. .SATURDAY...East to southeast winds 5 to 10 knots. Seas around 1 foot. Nearshore waters smooth to a light chop. A chance of showers and thunderstorms. .SATURDAY NIGHT...East to southeast winds 5 to 10 knots. Seas around 1 foot. Nearshore waters smooth to a light chop. A chance of showers and thunderstorms. .SUNDAY...Southeast to south winds near 5 knots. Seas around 1 foot. Nearshore waters smooth. A chance of showers and thunderstorms. .SUNDAY NIGHT...Southeast to south winds near 5 knots. Seas 1 foot or less. Nearshore waters smooth. A chance of showers and thunderstorms. .MONDAY...South to southwest winds near 5 knots. Seas 1 foot or less. Nearshore waters smooth. A chance of showers and thunderstorms. .MONDAY NIGHT...Southeast winds near 5 knots. Seas 1 foot or less. Nearshore waters smooth. A chance of showers and thunderstorms. .TUESDAY...Southeast winds near 5 knots. Seas 1 foot or less. Nearshore waters smooth. A slight chance of showers and thunderstorms. .TUESDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet. Nearshore waters smooth to a light chop. A chance of showers and thunderstorms. $$ GMZ052>055-072>075-042045- Straits of Florida from Ocean Reef to Craig Key out 20 NM- Straits of Florida from Craig Key to west end of Seven Mile Bridge out 20 NM- Straits of Florida from west end of Seven Mile Bridge to south of Halfmoon Shoal out 20 NM- Straits of Florida from Halfmoon Shoal to 20 NM west of Dry Tortugas out 20 NM- Straits of Florida from Ocean Reef to Craig Key 20 to 60 NM out- Straits of Florida from Craig Key to west end of Seven Mile Bridge 20 to 60 NM out- Straits of Florida from west end of Seven Mile Bridge to south of Halfmoon Shoal 20 to 60 NM out- Straits of Florida from Halfmoon Shoal to 20 NM west of Dry Tortugas 20 to 60 NM out- 432 AM EDT Fri Sep 4 2026 .TODAY...Southeast winds 5 to 10 knots. Seas around 1 foot. Wave Detail: East to southeast 1 foot at 3 seconds. A chance of showers and thunderstorms. .TONIGHT...East to southeast winds near 10 knots. Seas 1 to 2 feet. Wave Detail: East 2 feet at 3 seconds. A chance of showers and thunderstorms. .SATURDAY...East to southeast winds 5 to 10 knots. Seas 1 to 2 feet. Wave Detail: East to southeast 2 feet at 4 seconds. A chance of showers and thunderstorms. .SATURDAY NIGHT...East to southeast winds 5 to 10 knots. Seas 1 to 2 feet. A chance of showers and thunderstorms. .SUNDAY...East to southeast winds near 5 knots. Seas around 1 foot. A chance of showers and thunderstorms. .SUNDAY NIGHT...Southeast to south winds 5 to 10 knots. Seas around 1 foot. A chance of showers and thunderstorms. .MONDAY...South winds near 5 knots. Seas around 1 foot. A chance of showers and thunderstorms. .MONDAY NIGHT...Southeast winds near 5 knots. Seas around 1 foot. A chance of showers and thunderstorms. .TUESDAY...East to southeast winds near 5 knots. Seas around 1 foot. A slight chance of showers and thunderstorms. .TUESDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet. A chance of showers and thunderstorms. $$ GMZ033-034-042045- Gulf of America from East Cape Sable to Chokoloskee 20 to 60 NM out and beyond 5 fathoms- Gulf of America including Dry Tortugas and Rebecca Shoal Channel- 432 AM EDT Fri Sep 4 2026 .TODAY...Southeast winds near 5 knots. Seas 1 foot or less. Wave Detail: Southeast 1 foot at 2 seconds. A chance of showers and thunderstorms. .TONIGHT...East winds 5 to 10 knots. Seas around 1 foot. Wave Detail: East to southeast 1 foot at 2 seconds. A chance of showers and thunderstorms. .SATURDAY...Southeast winds 5 to 10 knots, becoming east. Seas 1 foot or less. Wave Detail: East to southeast 1 foot at 3 seconds. A chance of showers and thunderstorms. .SATURDAY NIGHT...East to southeast winds 5 to 10 knots. Seas 1 foot or less. A chance of showers and thunderstorms. .SUNDAY...Southeast winds near 5 knots. Seas 1 foot or less. Showers likely with a chance of thunderstorms. .SUNDAY NIGHT...Southeast to south winds near 5 knots. Seas 1 foot or less. A chance of showers and thunderstorms. .MONDAY...South to southwest winds near 5 knots. Seas 1 foot or less. A chance of showers and thunderstorms. .MONDAY NIGHT...Southeast winds near 5 knots. Seas 1 foot or less. A chance of showers and thunderstorms. .TUESDAY...East to southeast winds near 5 knots. Seas 1 foot or less. A chance of showers and thunderstorms. .TUESDAY NIGHT...East winds near 5 knots. Seas 1 foot or less. A chance of showers and thunderstorms. $$