FZUS52 KKEY 210818 CWFKEY Coastal Waters Forecast for the Florida Keys National Weather Service Key West FL 418 AM EDT Sun Jun 21 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. Wave Detail will include details about the period and direction of origin for the highest energy waves. Long-period swells coming from a different direction than the wind would be included in the Wave Detail. GMZ005-212030- Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas 418 AM EDT Sun Jun 21 2026 .SYNOPSIS...A broad, weak high pressure is centered over the Florida Peninsula. This will maintain a weakened pressure field across the Florida Keys and surrounding coastal waters. As a result, expect winds to be highly variable due to convection developing across South Florida during the afternoon and moving into our waters during the evening and overnight. Thereafter the high will flux in strength, resulting in breezes periodically entering peaks and lulls. The Approximate Shoreward Edge of the Gulf Stream as of June 15... 28 NM South of Dry Tortugas Light...on Loggerhead Key. 12 NM South of Cosgrove Shoal Light...off the Marquesas Keys. 11 NM South of Sand Key Light...off Key West. 14 NM South of Looe Key...off Big Pine Key. 13 NM Southeast of Sombrero Key Light...off Marathon. 8 NM Southeast of Alligator Reef Light...off Islamorada. 4 NM Southeast of Molasses Reef Light...off Key Largo. 3 NM East of Carysfort Reef Light...off Ocean Reef. Gulf Stream Information Courtesy of the National Weather Service in Key West, using data from RTOFS and NASA SPoRT SST. $$ GMZ031-212030- Florida Bay including Barnes Sound, Blackwater Sound, and Buttonwood Sound- 418 AM EDT Sun Jun 21 2026 .TODAY...Southeast to south winds 5 to 10 knots, becoming south to southwest and briefly decreasing to near 5 knots in the afternoon. Bay waters smooth to a light chop, becoming smooth. A slight chance of showers and thunderstorms. .TONIGHT...Northwest to north winds near 5 knots early, becoming north to northeast near 10 knots, then becoming east to southeast after midnight. Bay waters smooth, becoming a light chop. A slight chance of showers and thunderstorms. Winds higher and bay waters rough in and around thunderstorms. .MONDAY...Southeast winds near 10 knots, briefly decreasing to 5 to 10 knots in the afternoon. Bay waters a light chop, becoming smooth to a light chop. A slight chance of showers and thunderstorms. .MONDAY NIGHT...East to southeast winds near 10 knots. Bay waters a light chop. A slight chance of showers and thunderstorms. .TUESDAY...Southeast winds 5 to 10 knots. Bay waters smooth to a light chop. A slight chance of showers and thunderstorms. .TUESDAY NIGHT...East to southeast winds decreasing to near 5 knots. Bay waters becoming smooth. A slight chance of showers and thunderstorms. .WEDNESDAY...Southeast winds near 5 knots. Bay waters smooth. .WEDNESDAY NIGHT...East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop. A slight chance of showers and thunderstorms. .THURSDAY...Southeast winds 5 to 10 knots. Bay waters smooth to a light chop. A slight chance of showers and thunderstorms. .THURSDAY NIGHT...East to southeast winds near 10 knots. Bay waters a light chop. $$ GMZ032-035-212030- 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- 418 AM EDT Sun Jun 21 2026 .TODAY...Southeast to south winds 5 to 10 knots, briefly becoming variable near 5 knots in the afternoon. Seas 1 foot or less. Nearshore waters smooth to a light chop, becoming smooth. A slight chance of showers and thunderstorms. .TONIGHT...North to northeast winds 5 to 10 knots early, increasing to near 10 knots, then becoming east to southeast after midnight. Seas 1 foot or less, building to around 1 foot. Nearshore waters smooth to a light chop, becoming a light chop. A slight chance of showers and thunderstorms. Winds and seas higher in and around thunderstorms. .MONDAY...Southeast winds near 10 knots, decreasing to 5 to 10 knots. Seas around 1 foot. Nearshore waters a light chop, becoming smooth to a light chop. A slight chance of showers and thunderstorms. .MONDAY NIGHT...East to southeast winds 5 to 10 knots, increasing to near 10 knots. Seas around 1 foot, except building to 1 to 2 feet west of the Marquesas Keys. Nearshore waters smooth to a light chop, becoming a light chop. A slight chance of showers and thunderstorms. .TUESDAY...Southeast winds near 10 knots, decreasing to 5 to 10 knots. Seas around 1 foot, subsiding to 1 foot or less. West of the Marquesas Keys, seas 1 to 2 feet, subsiding to around 1 foot. Nearshore waters a light chop, becoming smooth to a light chop. A slight chance of showers and thunderstorms. .TUESDAY NIGHT...East to southeast winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop. A slight chance of showers and thunderstorms. .WEDNESDAY...East to southeast winds near 5 knots. Seas 1 foot or less. Nearshore waters smooth. A slight chance of showers and thunderstorms. .WEDNESDAY NIGHT...East to southeast winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop. A slight chance of showers and thunderstorms. .THURSDAY...East to southeast winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop. A slight chance of showers. .THURSDAY NIGHT...East to southeast winds near 10 knots. Seas around 1 foot, except building to 1 to 2 feet west of the Marquesas Keys. Nearshore waters a light chop. A slight chance of showers. $$ GMZ042>044-212030- 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- 418 AM EDT Sun Jun 21 2026 .TODAY...Southeast to south winds 5 to 10 knots, becoming south to southwest and briefly decreasing to near 5 knots in the afternoon. Seas around 1 foot. Nearshore waters smooth to a light chop, becoming smooth. A slight chance of showers and thunderstorms. .TONIGHT...North to northeast winds 5 to 10 knots early, increasing to near 10 knots, then becoming east to southeast after midnight. Seas around 1 foot. Nearshore waters smooth to a light chop, becoming a light chop. A slight chance of showers and thunderstorms. Winds and seas higher in and around thunderstorms. .MONDAY...East to southeast winds near 10 knots, briefly decreasing to 5 to 10 knots in the afternoon. Seas around 1 foot. Nearshore waters a light chop, becoming smooth to a light chop. A slight chance of showers and thunderstorms. .MONDAY NIGHT...East to southeast winds near 10 knots, increasing to 10 to 15 knots. Seas building to 1 to 2 feet. Nearshore waters a light chop, becoming a light to moderate chop. A slight chance of showers and thunderstorms. .TUESDAY...East to southeast winds near 10 knots, decreasing to 5 to 10 knots. Seas 1 to 2 feet. Nearshore waters a light chop, becoming smooth to a light chop. A slight chance of showers and thunderstorms. .TUESDAY NIGHT...East winds 5 to 10 knots. Seas around 1 foot. Nearshore waters smooth to a light chop. .WEDNESDAY...East winds 5 to 10 knots. Seas around 1 foot. Nearshore waters smooth. .WEDNESDAY NIGHT...East to southeast winds 5 to 10 knots. Seas around 1 foot. Nearshore waters smooth to a light chop. A slight chance of showers and thunderstorms. .THURSDAY...East to southeast winds 5 to 10 knots. Seas 1 to 2 feet. Nearshore waters smooth to a light chop. .THURSDAY NIGHT...East to southeast winds near 10 knots, increasing to 10 to 15 knots. Seas around 2 feet, building to 2 to 3 feet. Nearshore waters a light chop, becoming a light to moderate chop. $$ GMZ052>055-072>075-212030- 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- 418 AM EDT Sun Jun 21 2026 .TODAY...Southeast winds 5 to 10 knots, briefly becoming variable near 5 knots in the afternoon. Seas around 1 foot. Wave Detail: East to southeast 1 foot at 3 seconds. .TONIGHT...North to northeast winds 5 to 10 knots early, increasing to near 10 knots, then becoming east to southeast after midnight. Seas around 1 foot. Wave Detail: Northeast 1 foot at 3 seconds. A slight chance of showers and thunderstorms. .MONDAY...East to southeast winds near 10 knots. Seas 1 to 2 feet, building to around 2 feet. Wave Detail: East to southeast 2 feet at 4 seconds. A slight chance of showers and thunderstorms. .MONDAY NIGHT...East winds 10 to 15 knots. Seas 2 to 3 feet. A slight chance of showers and thunderstorms. .TUESDAY...East to southeast winds 10 to 15 knots, becoming northeast to east and briefly decreasing to near 10 knots. Seas 2 to 3 feet. .TUESDAY NIGHT...Northeast to east winds 10 to 15 knots, becoming east near 10 knots. Seas 2 to 3 feet, subsiding to around 2 feet. A slight chance of showers and thunderstorms. .WEDNESDAY...East winds 5 to 10 knots. Seas 1 to 2 feet. A slight chance of showers and thunderstorms. .WEDNESDAY NIGHT...East winds near 10 knots. Seas around 2 feet. A slight chance of showers and thunderstorms. .THURSDAY...East to southeast winds near 10 knots. Seas around 2 feet. .THURSDAY NIGHT...East to southeast winds 10 to 15 knots. Seas 2 to 3 feet. A slight chance of showers. $$ GMZ033-034-212030- Gulf of America from East Cape Sable to Chokoloskee 20 to 60 NM out and beyond 5 fathoms- Gulf of America including Dry Tortugas and Rebecca Shoal Channel- 418 AM EDT Sun Jun 21 2026 .TODAY...Southeast to south winds 5 to 10 knots, becoming northwest to north and briefly decreasing to near 5 knots. Seas around 1 foot. Wave Detail: Southeast 1 foot at 3 seconds and west 1 foot at 4 seconds. A slight chance of showers and thunderstorms. .TONIGHT...North to northeast winds 5 to 10 knots, becoming east to southeast after midnight. Seas around 1 foot. Wave Detail: East 1 foot at 3 seconds. A slight chance of showers and thunderstorms. .MONDAY...East to southeast winds 5 to 10 knots. Seas around 1 foot. Wave Detail: East to southeast 1 foot at 3 seconds. A slight chance of showers and thunderstorms. .MONDAY NIGHT...Northeast to east winds 5 to 10 knots, becoming east to southeast near 10 knots. Seas around 1 foot, building to 1 to 2 feet. A slight chance of showers and thunderstorms. .TUESDAY...Southeast winds 5 to 10 knots. Seas 1 to 2 feet, subsiding to around 1 foot. A slight chance of showers and thunderstorms. .TUESDAY NIGHT...Northeast to east winds 5 to 10 knots. Seas subsiding to 1 foot or less. A slight chance of showers and thunderstorms. .WEDNESDAY...East winds near 5 knots. Seas 1 foot or less. A slight chance of showers and thunderstorms. .WEDNESDAY NIGHT...Northeast to east winds near 5 knots, becoming east to southeast 5 to 10 knots. Seas building to around 1 foot. A slight chance of showers and thunderstorms. .THURSDAY...East to southeast winds 5 to 10 knots. Seas around 1 foot. .THURSDAY NIGHT...East to southeast winds near 10 knots. Seas 1 to 2 feet. A slight chance of showers and thunderstorms. $$