GMZ005-180830-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
417 PM EDT Thu Sep 17 2026
.SYNOPSIS...
High pressure across the North Atlantic will maintain gentle to
moderate northeast to east breezes through tonight. Winds will
then slacken for Friday through the start of the weekend,
becoming light to gentle out of the east and southeast, as the
high north of the Keys marine zones weakens. An increasingly wet
pattern will develop across the Florida Keys coastal waters
through at least Sunday, as an upper- level low retrogrades
westward towards South Florida and then eventually the Gulf.
Confidence is low in the marine forecast for early next week,
largely determined by where the upper-level low resides for that
time frame.
The Approximate Shoreward Edge of the Gulf Stream as of
September 11, 2026...
26 NM south of Dry Tortugas Light, on Loggerhead Key
15 NM south of Cosgrove Shoal Light, off the Marquesas Keys
15 NM south of Sand Key Light, off Key West
11 NM south-southeast of Looe Key, off Big Pine Key
8 NM southeast of Sombrero Key Light, off Marathon
6 NM southeast of Alligator Reef Light, off Islamorada
2 NM southeast of Molasses Reef Light, off Key Largo
1 NM east-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.
$$
GMZ033-034-180830- Gulf of America from East Cape Sable to Chokoloskee 20 to 60 NM out and beyond 5 fathoms- Gulf of America including Dry Tortugas and Rebecca Shoal Channel- 417 PM EDT Thu Sep 17 2026 TONIGHT Northeast to east winds 10 to 15 knots. Seas 2 to 3 feet. Wave Detail: Northeast to east 3 feet at 4 seconds. Showers likely with a chance of thunderstorms. FRIDAY East winds near 10 knots, decreasing to 5 to 10 knots. Seas 2 to 3 feet, subsiding to 1 to 2 feet. Wave Detail: East 2 feet at 4 seconds. Showers likely with a chance of thunderstorms. FRIDAY NIGHT East winds 5 to 10 knots. Seas 1 to 2 feet. Showers likely with a chance of thunderstorms. SATURDAY East to southeast winds 5 to 10 knots. Seas 1 to 2 feet. Showers likely with a chance of thunderstorms. SATURDAY NIGHT East to southeast winds 5 to 10 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. SUNDAY South winds 5 to 10 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. SUNDAY NIGHT South to southwest winds 5 to 10 knots. Seas around 1 foot. Showers and thunderstorms likely. MONDAY South to southwest winds near 5 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. MONDAY NIGHT Southeast to south winds 5 to 10 knots, increasing to near 10 knots. Seas 1 to 2 feet. Showers likely with a chance of thunderstorms. TUESDAY Southeast to south winds 5 to 10 knots. Seas 1 to 2 feet. Showers likely with a chance of thunderstorms. TUESDAY NIGHT Southeast winds 5 to 10 knots. Seas 1 to 2 feet. Showers likely with a chance of thunderstorms. $$
GMZ033-034-180830- 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- 417 PM EDT Thu Sep 17 2026 TONIGHT Northeast to east winds 10 to 15 knots. Seas 2 to 3 feet. Wave Detail: Northeast to east 3 feet at 4 seconds. Showers likely with a chance of thunderstorms. FRIDAY East winds near 10 knots, decreasing to 5 to 10 knots. Seas 2 to 3 feet, subsiding to 1 to 2 feet. Wave Detail: East 2 feet at 4 seconds. Showers likely with a chance of thunderstorms. FRIDAY NIGHT East winds 5 to 10 knots. Seas 1 to 2 feet. Showers likely with a chance of thunderstorms. SATURDAY East to southeast winds 5 to 10 knots. Seas 1 to 2 feet. Showers likely with a chance of thunderstorms. SATURDAY NIGHT East to southeast winds 5 to 10 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. SUNDAY South winds 5 to 10 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. SUNDAY NIGHT South to southwest winds 5 to 10 knots. Seas around 1 foot. Showers and thunderstorms likely. MONDAY South to southwest winds near 5 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. MONDAY NIGHT Southeast to south winds 5 to 10 knots, increasing to near 10 knots. Seas 1 to 2 feet. Showers likely with a chance of thunderstorms. TUESDAY Southeast to south winds 5 to 10 knots. Seas 1 to 2 feet. Showers likely with a chance of thunderstorms. TUESDAY NIGHT Southeast winds 5 to 10 knots. Seas 1 to 2 feet. Showers likely with a chance of thunderstorms. $$