FZUS52 KKEY 170818 CWFKEY Coastal Waters Forecast for the Florida Keys National Weather Service Key West FL 418 AM EDT Fri Apr 17 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. GMZ005-172030- Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas 418 AM EDT Fri Apr 17 2026 .SYNOPSIS...High pressure over the central North Atlantic will allow breezes to lull during the mornings and early afternoons, then peak during the evenings through Saturday. An approaching frontal boundary will push the high further east on Sunday, allowing for a brief period of slackening breezes. The front will slide through sometime Sunday with a strong high pressure quickly filling in the wake on Monday. This will result in breezes freshening to fresh to strong breezes through at least Tuesday. The Approximate Shoreward Edge of the Gulf Stream as of April 16... 16 NM South of Dry Tortugas Light...on Loggerhead Key. 12 NM South of Cosgrove Shoal Light...off the Marquesas Keys. 22 NM South of Sand Key Light...off Key West. 30 NM South of Looe Key...off Big Pine Key. 26 NM Southeast of Sombrero Key Light...off Marathon. 20 NM Southeast of Alligator Reef Light...off Islamorada. 15 NM Southeast of Molasses Reef Light...off Key Largo. 9 NM Southeast of Carysfort Reef Light...off Ocean Reef. Gulf Stream Information Courtesy of the National Weather Service in Key West based on products from NASA SPoRT and RTOFS. $$ GMZ031-172030- Florida Bay including Barnes Sound, Blackwater Sound, and Buttonwood Sound- 418 AM EDT Fri Apr 17 2026 .TODAY...Northeast to east winds near 10 knots. Bay waters a light chop. A slight chance of showers. .TONIGHT...Northeast to east winds 10 to 15 knots. Bay waters a light to moderate chop. A slight chance of showers. .SATURDAY...East winds near 10 knots. Bay waters a light chop. .SATURDAY NIGHT...East winds near 10 knots. Bay waters a light chop. A slight chance of showers. .SUNDAY...East to southeast winds 5 to 10 knots, briefly decreasing to near 5 knots. Bay waters smooth to a light chop, becoming smooth. A slight chance of showers. .SUNDAY NIGHT...Northwest to north winds 5 to 10 knots, increasing to near 10 knots. Bay waters smooth to a light chop, becoming a light chop. A slight chance of showers. .MONDAY...North to northeast winds near 10 knots, becoming northeast to east 10 to 15 knots. Bay waters a light chop, becoming a light to moderate chop. A slight chance of showers. .MONDAY NIGHT...Northeast winds 15 to 20 knots, increasing to 20 to 25 knots. Bay waters choppy, becoming very rough. A slight chance of showers. .TUESDAY...Northeast to east winds near 25 knots. Bay waters extremely rough. .TUESDAY NIGHT...Northeast to east winds near 25 knots, decreasing to 20 to 25 knots. Bay waters extremely rough, becoming very rough. $$ GMZ032-035-172030- 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 Fri Apr 17 2026 .TODAY...Northeast winds near 10 knots, briefly decreasing to 5 to 10 knots in the afternoon. 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. .TONIGHT...Northeast to east 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. .SATURDAY...East winds near 10 knots. Seas 1 to 2 feet. Nearshore waters a light chop. .SATURDAY NIGHT...East winds near 10 knots. Seas 1 to 2 feet. Nearshore waters a light chop. A slight chance of showers. .SUNDAY...Northeast to east winds 5 to 10 knots, becoming northwest to north. Seas around 1 foot, subsiding to 1 foot or less. Nearshore waters smooth to a light chop. .SUNDAY NIGHT...Northwest to north winds 5 to 10 knots, increasing to near 10 knots. Seas 1 foot or less, building to 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. .MONDAY...North to northeast winds 10 to 15 knots. Seas 1 to 2 feet, except building to 2 to 3 feet west of the Marquesas Keys. Nearshore waters a light to moderate chop. A slight chance of showers. .MONDAY NIGHT...Northeast winds 15 to 20 knots, increasing to 20 to 25 knots. Seas building to 2 to 4 feet, occasionally to 5 feet. West of the Marquesas Keys, seas 3 to 4 feet, occasionally to 5 feet, building to 5 to 6 feet, occasionally to 8 feet. Nearshore waters choppy, becoming very rough. A slight chance of showers. .TUESDAY...Northeast to east winds near 25 knots. Seas 3 to 5 feet, occasionally to 6 feet, except 6 to 7 feet, occasionally to 9 feet west of the Marquesas Keys. Nearshore waters extremely rough. .TUESDAY NIGHT...Northeast to east winds near 25 knots, decreasing to 20 to 25 knots. Seas 3 to 5 feet, occasionally to 6 feet, except 6 to 7 feet, occasionally to 9 feet west of the Marquesas Keys. Nearshore waters extremely rough, becoming very rough. $$ GMZ042>044-172030- 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 Fri Apr 17 2026 .TODAY...Northeast winds near 10 knots. Seas around 2 feet. Nearshore waters a light chop. A slight chance of showers. .TONIGHT...Northeast to east winds 10 to 15 knots. Seas 2 to 3 feet. Nearshore waters a light to moderate chop. A slight chance of showers. .SATURDAY...East winds 10 to 15 knots, decreasing to near 10 knots. Seas 2 to 3 feet. Nearshore waters a light to moderate chop, becoming a light chop. .SATURDAY NIGHT...East winds 10 to 15 knots. Seas around 2 feet. Nearshore waters a light chop. A slight chance of showers. .SUNDAY...East winds near 10 knots, becoming north to northeast 5 to 10 knots. 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. .SUNDAY NIGHT...North to northeast winds 5 to 10 knots, increasing to near 10 knots. Seas around 1 foot, except building to 1 to 2 feet west of Cosgrove Shoal Light. Nearshore waters smooth to a light chop, becoming a light chop. A slight chance of showers. .MONDAY...North to northeast winds 10 to 15 knots. Seas around 1 foot, building to 1 to 2 feet. West of Cosgrove Shoal Light, seas 1 to 2 feet, building to 2 to 3 feet. Nearshore waters a light to moderate chop. A slight chance of showers. .MONDAY NIGHT...Northeast winds 15 to 20 knots, increasing to 20 to 25 knots. Seas 2 to 3 feet, building to 3 to 5 feet, occasionally to 6 feet. West of Cosgrove Shoal Light, seas 3 to 4 feet, occasionally to 5 feet, building to 5 to 6 feet, occasionally to 8 feet. Nearshore waters choppy, becoming very rough. A slight chance of showers. .TUESDAY...Northeast to east winds near 25 knots. Seas 4 to 6 feet, occasionally to 8 feet, except 6 to 8 feet, occasionally to 10 feet west of Cosgrove Shoal Light. Nearshore waters extremely rough. .TUESDAY NIGHT...Northeast to east winds near 25 knots, decreasing to 20 to 25 knots. Seas 5 to 8 feet, occasionally to 10 feet. Nearshore waters extremely rough, becoming very rough. $$ GMZ052>055-072>075-172030- 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 Fri Apr 17 2026 .TODAY...Northeast to east winds 10 to 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: Northeast to east 4 feet at 5 seconds. A slight chance of showers. .TONIGHT...Northeast to east winds 10 to 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: Northeast to east 4 feet at 5 seconds. A slight chance of showers. .SATURDAY...East winds 10 to 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 6 seconds. A slight chance of showers. .SATURDAY NIGHT...East winds 10 to 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. A slight chance of showers. .SUNDAY...East to southeast winds near 10 knots, becoming northeast to east 5 to 10 knots. Seas 2 to 3 feet, subsiding to 1 to 2 feet. A slight chance of showers. .SUNDAY NIGHT...Northeast winds 5 to 10 knots, increasing to 10 to 15 knots. Seas 1 to 2 feet. A slight chance of showers. .MONDAY...North to northeast winds 10 to 15 knots, increasing to near 15 knots. Seas 2 to 3 feet, building to 3 to 4 feet, occasionally to 5 feet. A slight chance of showers. .MONDAY NIGHT...Northeast winds 15 to 20 knots, increasing to 20 to 25 knots. Seas 4 to 6 feet, occasionally to 8 feet, building to 7 to 10 feet, occasionally to 13 feet. A slight chance of showers and thunderstorms. .TUESDAY...Northeast to east winds near 25 knots. Seas 9 to 12 feet, occasionally to 15 feet. A slight chance of showers. .TUESDAY NIGHT...Northeast to east winds near 25 knots. Seas 11 to 14 feet, occasionally to 18 feet, subsiding to 9 to 12 feet, occasionally to 15 feet. A slight chance of showers. $$ GMZ033-034-172030- Gulf of America from East Cape Sable to Chokoloskee 20 to 60 NM out and beyond 5 fathoms- Gulf of America including Dry Tortugas and Rebecca Shoal Channel- 418 AM EDT Fri Apr 17 2026 .TODAY...North to northeast winds near 10 knots, decreasing to 5 to 10 knots. Seas 1 to 2 feet. Wave Detail: North to northeast 2 feet at 3 seconds. .TONIGHT...Northeast to east winds 5 to 10 knots, increasing to near 10 knots. Seas 1 to 2 feet. Wave Detail: East 2 feet at 3 seconds and northwest to north 1 foot at 3 seconds. .SATURDAY...East winds near 10 knots, decreasing to 5 to 10 knots. Seas 1 to 2 feet. Wave Detail: East 2 feet at 4 seconds. .SATURDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet. A slight chance of showers. .SUNDAY...Northeast to east winds 5 to 10 knots, becoming northwest to north. Seas 1 to 2 feet, subsiding to around 1 foot. .SUNDAY NIGHT...Northwest to north winds near 10 knots, becoming north to northeast 10 to 15 knots. Seas around 1 foot, building to 2 to 3 feet. .MONDAY...North to northeast winds 10 to 15 knots, increasing to near 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. A slight chance of showers. .MONDAY NIGHT...Northeast winds 15 to 20 knots, increasing to near 25 knots. Seas 3 to 5 feet, occasionally to 6 feet, building to 5 to 7 feet, occasionally to 9 feet. .TUESDAY...Northeast to east winds 20 to 25 knots, decreasing to near 20 knots. Seas 6 to 9 feet, occasionally to 11 feet, subsiding to 5 to 8 feet, occasionally to 10 feet. .TUESDAY NIGHT...Northeast to east winds 20 to 25 knots. Seas 5 to 8 feet, occasionally to 10 feet. $$