National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

NWS Marine Forecast

   GMZ005-220830-  Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas  429 PM EDT Fri Aug 21 2026      .SYNOPSIS...  A split ridge pattern remains in place across the Florida Keys  coastal waters. This will promote generally light to gentle  southeast to south breezes through Sunday, becoming variable at  times during the afternoon hours. As North Atlantic ridging  builds westward, southeasterly breezes will become more  established for Sunday night through the middle of next week,  becoming gentle and at times moderate during the overnight hours.    The Approximate Shoreward Edge of the Gulf Stream as of August  19, 2026...    37 NM south of Dry Tortugas Light, on Loggerhead Key  20 NM south-southeast of Cosgrove Shoal Light, off the Marquesas Keys  14 NM south-southeast of Sand Key Light, off Key West  10 NM south-southeast of Looe Key, off Big Pine Key  10 NM south-southeast of Sombrero Key Light, off Marathon  3 NM southeast of Alligator Reef Light, off Islamorada  1 NM west-northwest of Molasses Reef Light, off Key Largo  1 NM east-southeast of Carysfort Reef Light, off Ocean Reef    Gulf Stream Information Courtesy of the Naval Oceanographic  Office.    $$
   GMZ033-034-220830-  Gulf of America from East Cape Sable to Chokoloskee 20 to 60 NM  out and beyond 5 fathoms-  Gulf of America including Dry Tortugas and Rebecca Shoal Channel-  429 PM EDT Fri Aug 21 2026    TONIGHT  Variable near 5 knots, becoming southeast to south and  increasing to 5 to 10 knots. Seas 1 foot or less, building to  around 1 foot. Wave Detail: Northwest 1 foot at 4 seconds. A  slight chance of showers and thunderstorms.  SATURDAY  Southeast to south winds near 5 knots, becoming  variable. Seas 1 foot or less. Wave Detail: Northwest 1 foot at 4  seconds. A slight chance of showers and thunderstorms.  SATURDAY NIGHT  Variable near 5 knots, becoming southeast. Seas  1 foot or less.  SUNDAY  Variable near 5 knots. Seas 1 foot or less. A slight  chance of showers and thunderstorms.  SUNDAY NIGHT  East to southeast winds near 5 knots. Seas 1 foot  or less. A slight chance of showers and thunderstorms.  MONDAY  East winds 5 to 10 knots. Seas around 1 foot. A chance  of showers with a slight chance of thunderstorms.  MONDAY NIGHT  East to southeast winds 5 to 10 knots. Seas  around 1 foot. A chance of showers and thunderstorms.  TUESDAY  East to southeast winds 5 to 10 knots. Seas around 1  foot. A chance of showers and thunderstorms.  TUESDAY NIGHT  East winds near 10 knots. Seas 1 to 2 feet.  A chance of showers and thunderstorms.  WEDNESDAY  East to southeast winds 5 to 10 knots. Seas 1 to  2 feet. A chance of showers and thunderstorms.  WEDNESDAY NIGHT  East to southeast winds near 10 knots. Seas  1 to 2 feet. Showers likely with a chance of thunderstorms.    $$