Coastal Waters Forecast
Issued by NWS Key West, FL
Issued by NWS Key West, FL
563 FZUS52 KKEY 100227 CWFKEY Coastal Waters Forecast for the Florida Keys National Weather Service Key West FL 1027 PM EDT Sun Aug 9 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. GMZ005-101430- Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas 1027 PM EDT Sun Aug 9 2026 .SYNOPSIS...Ridging will gradually build in across the region, and will maintain gentle to moderate easterly to southeasterly breezes on our waters. Marine caution headlines will be in place for Hawk Channel and the Florida Straits due to a brief period of freshening breezes overnight. However, winds will trend slightly downwards heading towards mid week as the ridge settles southward across Central Florida. Expect swings in wind speeds, generally lulling during the day and peaking overnight. Shower and thunder chances will be near to below normal through the forecast. The Approximate Shoreward Edge of the Gulf Stream as of August 7, 2026... 25 NM South of Dry Tortugas Light...on Loggerhead Key. 15 NM South of Cosgrove Shoal Light...off the Marquesas Keys. 19 NM South of Sand Key Light...off Key West. 29 NM South of Looe Key...off Big Pine Key. 16 NM Southeast of Sombrero Key Light...off Marathon. 4 NM Southeast of Alligator Reef Light...off Islamorada. 2 NM Southeast of Molasses Reef Light...off Key Largo. 1 NM Southeast 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. $$ GMZ031-101430- Florida Bay including Barnes Sound, Blackwater Sound, and Buttonwood Sound- 1027 PM EDT Sun Aug 9 2026 .OVERNIGHT...East winds near 15 knots, becoming east to southeast. Bay waters a moderate chop. A chance of showers with a slight chance of thunderstorms. .MONDAY...East to southeast winds 10 to 15 knots. Bay waters a light to moderate chop. A slight chance of showers and thunderstorms. .MONDAY NIGHT...East winds 10 to 15 knots. Bay waters a light to moderate chop. A slight chance of showers and thunderstorms. .TUESDAY...East winds decreasing to near 10 knots. Bay waters becoming a light chop. A slight chance of showers and thunderstorms. .TUESDAY NIGHT...East winds near 10 knots, decreasing to 5 to 10 knots. Bay waters a light chop, becoming smooth to a light chop. A slight chance of showers and thunderstorms. .WEDNESDAY...East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop. A slight chance of showers and thunderstorms. .WEDNESDAY NIGHT...East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop. .THURSDAY...East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop. A slight chance of showers. .THURSDAY NIGHT...East winds near 10 knots. Bay waters a light chop. .FRIDAY...East winds 10 to 15 knots. Bay waters a light to moderate chop. A chance of showers and thunderstorms. .FRIDAY NIGHT...East winds 10 to 15 knots. Bay waters a light to moderate chop. A slight chance of showers and thunderstorms. $$ GMZ032-035-101430- 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- 1027 PM EDT Sun Aug 9 2026 .OVERNIGHT...East to southeast winds near 15 knots. Seas 1 to 2 feet, except 2 to 3 feet west of the Marquesas Keys. Nearshore waters a moderate chop. A chance of showers with a slight chance of thunderstorms. .MONDAY...East to southeast winds near 15 knots, decreasing to 10 to 15 knots. Seas 1 to 2 feet. West of the Marquesas Keys, seas 2 to 3 feet, subsiding to around 2 feet. Nearshore waters a moderate chop, becoming a light to moderate chop. A slight chance of showers and thunderstorms. .MONDAY NIGHT...East winds 10 to 15 knots. Seas 1 to 2 feet. Nearshore waters a light to moderate chop. A slight chance of showers and thunderstorms. .TUESDAY...East winds decreasing to near 10 knots. Seas subsiding to around 1 foot. Nearshore waters becoming a light chop. A slight chance of showers and thunderstorms. .TUESDAY NIGHT...East winds near 10 knots. Seas around 1 foot. Nearshore waters a light chop. A slight chance of showers and thunderstorms. .WEDNESDAY...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 NIGHT AND THURSDAY...East to southeast winds 5 to 10 knots. Seas 1 foot or less. Nearshore waters smooth to a light chop. .THURSDAY NIGHT...East winds near 10 knots. Seas 1 foot or less. Nearshore waters a light chop. .FRIDAY...East winds near 10 knots, increasing to 10 to 15 knots. Seas 1 foot or less, building to around 1 foot. Nearshore waters a light chop, becoming a light to moderate chop. A chance of showers and thunderstorms. .FRIDAY NIGHT...East winds increasing to near 15 knots. Seas building to 1 to 2 feet. Nearshore waters becoming a moderate chop. A chance of showers and thunderstorms. $$ GMZ042>044-101430- 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- 1027 PM EDT Sun Aug 9 2026 ...SMALL CRAFT SHOULD EXERCISE CAUTION FOR INCREASING WINDS... .OVERNIGHT...East to southeast winds near 15 knots, increasing to 15 to 20 knots. Seas 1 to 3 feet, building to 2 to 4 feet, occasionally to 5 feet. Nearshore waters a moderate chop, becoming choppy. A chance of showers with a slight chance of thunderstorms. .MONDAY...East to southeast winds near 15 knots early, decreasing to 10 to 15 knots. Seas 2 to 3 feet. Nearshore waters a moderate chop, becoming a light to moderate chop. A slight chance of showers and thunderstorms. .MONDAY NIGHT AND TUESDAY...East winds 10 to 15 knots. Seas 2 to 3 feet. Nearshore waters a light to moderate chop. A slight chance of showers and thunderstorms. .TUESDAY NIGHT...East winds 10 to 15 knots, decreasing to near 10 knots. Seas 2 to 3 feet, subsiding to 1 to 2 feet. Nearshore waters a light to moderate chop, becoming a light chop. A slight chance of showers and thunderstorms. .WEDNESDAY...East to southeast winds near 10 knots. Seas 1 to 2 feet. Nearshore waters a light chop. A slight chance of showers and thunderstorms. .WEDNESDAY NIGHT...East to southeast winds 5 to 10 knots. Seas 1 to 2 feet. Nearshore waters smooth to a light chop. .THURSDAY...East winds 5 to 10 knots. Seas 1 to 2 feet. Nearshore waters smooth to a light chop. .THURSDAY NIGHT...East winds near 10 knots. Seas 1 to 2 feet. Nearshore waters a light chop. .FRIDAY...East winds 10 to 15 knots, increasing to near 15 knots. Seas 1 to 2 feet, building to 2 to 3 feet. Nearshore waters a light to moderate chop, becoming a moderate chop. A chance of showers and thunderstorms. .FRIDAY NIGHT...East winds near 15 knots. Seas 2 to 3 feet. Nearshore waters a moderate chop. A slight chance of showers and thunderstorms. $$ GMZ052>055-072>075-101430- 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- 1027 PM EDT Sun Aug 9 2026 ...SMALL CRAFT SHOULD EXERCISE CAUTION FOR INCREASING WINDS... .OVERNIGHT...East winds near 15 knots, increasing to 15 to 20 knots. Seas 2 to 3 feet, building to 3 to 5 feet, occasionally to 6 feet. Wave Detail: East 4 feet at 5 seconds. A chance of showers with a slight chance of thunderstorms. .MONDAY...East winds near 15 knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail: East to southeast 4 feet at 5 seconds. A slight chance of showers and thunderstorms. .MONDAY NIGHT...East winds decreasing to 10 to 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 5 seconds. A slight chance of showers and thunderstorms. .TUESDAY...East winds 10 to 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. A slight chance of showers and thunderstorms. .TUESDAY NIGHT...East winds 10 to 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. A slight chance of showers and thunderstorms. .WEDNESDAY...East winds 10 to 15 knots. Seas 2 to 3 feet. A slight chance of showers and thunderstorms. .WEDNESDAY NIGHT...East winds 10 to 15 knots, decreasing to near 10 knots. Seas 2 to 3 feet. .THURSDAY...East winds 10 to 15 knots. Seas 2 to 3 feet. .THURSDAY NIGHT...East winds 10 to 15 knots. Seas 2 to 3 feet. A slight chance of showers. .FRIDAY...East winds 10 to 15 knots, increasing to near 15 knots. Seas 2 to 3 feet. A chance of showers and thunderstorms. .FRIDAY NIGHT...East winds near 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. A slight chance of showers and thunderstorms. $$ GMZ033-034-101430- Gulf of America from East Cape Sable to Chokoloskee 20 to 60 NM out and beyond 5 fathoms- Gulf of America including Dry Tortugas and Rebecca Shoal Channel- 1027 PM EDT Sun Aug 9 2026 .OVERNIGHT...Southeast winds near 15 knots. Seas 2 to 3 feet. Wave Detail: East 3 feet at 4 seconds. A chance of showers with a slight chance of thunderstorms. .MONDAY...East to southeast winds near 15 knots early, decreasing to 10 to 15 knots. Seas 2 to 3 feet. Wave Detail: East to southeast 3 feet at 4 seconds. A slight chance of showers and thunderstorms. .MONDAY NIGHT...East winds 10 to 15 knots. Seas 2 to 3 feet. Wave Detail: East 2 feet at 4 seconds. A slight chance of showers and thunderstorms. .TUESDAY...East to southeast winds 10 to 15 knots, becoming east and decreasing to near 10 knots. Seas 2 to 3 feet, subsiding to 1 to 2 feet. A slight chance of showers and thunderstorms. .TUESDAY NIGHT...East winds 10 to 15 knots. Seas 1 to 2 feet. A slight chance of showers and thunderstorms. .WEDNESDAY...East winds 5 to 10 knots. Seas 1 to 2 feet. A slight chance of showers and thunderstorms. .WEDNESDAY NIGHT...East winds 5 to 10 knots. Seas around 1 foot. A slight chance of showers. .THURSDAY...East winds 5 to 10 knots. Seas around 1 foot. .THURSDAY NIGHT...East winds 5 to 10 knots. Seas around 1 foot. A slight chance of showers and thunderstorms. .FRIDAY...East winds 5 to 10 knots, increasing to near 10 knots. Seas around 1 foot, building to 1 to 2 feet. A chance of showers and thunderstorms. .FRIDAY NIGHT...East winds increasing to 10 to 15 knots. Seas 1 to 2 feet, building to around 2 feet. A chance of showers and thunderstorms. $$ MJV