GMZ005-182030-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
424 AM EDT Fri Sep 18 2026
.SYNOPSIS...
High pressure in the north Atlantic weakens today and this will
allow winds to slacken across the Florida Keys coastal waters with
winds mainly light to gentle through the remainder of the week
and into the weekend. In addition, an increasingly wet weather
pattern will continue to develop across the Florida Keys coastal
waters through early next week as an upper level low retrogrades
westward across the Florida peninsula and eventually shifts into
the Gulf this weekend. As a result, scattered to occasional
numerous showers and thunderstorms will be a daily occurence with
gusty winds, lightning strikes, blinding downpours, and locally
hazardous seas being the main hazards mariners could encounter in
the vicinity of this activity. The upper level low is forecast to
move out of the area early next week with winds becoming more
southerly and breezes remaining light to gentle. Rain chances will
also continue to remain elevated into next week as deep moisture
lingers across the Florida Keys coastal waters in the wake of the
departing weather disturbance.
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.
$$
GMZ033-034-182030- Gulf of America from East Cape Sable to Chokoloskee 20 to 60 NM out and beyond 5 fathoms- Gulf of America including Dry Tortugas and Rebecca Shoal Channel- 424 AM EDT Fri Sep 18 2026 TODAY Northeast to east winds 5 to 10 knots. Seas 1 to 2 feet. Wave Detail: East 2 feet at 4 seconds. A chance of showers and thunderstorms. TONIGHT Northeast to east winds 5 to 10 knots. Seas around 1 foot. Wave Detail: Northeast to east 1 foot at 4 seconds. Showers likely with a chance of thunderstorms. SATURDAY East winds near 5 knots. Seas 1 foot or less. Wave Detail: East 1 foot at 3 seconds. Showers likely with a chance of thunderstorms. SATURDAY NIGHT East to southeast winds 5 to 10 knots. Seas 1 around 1 foot. A chance of showers and thunderstorms. SUNDAY Southeast to south winds near 5 knots. Seas 1 foot or less. Showers likely with a chance of thunderstorms. SUNDAY NIGHT South to southwest winds near 5 knots, becoming southeast to south. Seas 1 foot or less. A chance of showers and thunderstorms. MONDAY South to southwest winds 5 to 10 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. MONDAY NIGHT South winds 5 to 10 knots. Seas around 1 foot. Showers with a chance of thunderstorms. TUESDAY Southeast to south winds near 5 knots. Seas around 1 foot. Showers and thunderstorms likely. TUESDAY NIGHT Southeast winds 5 to 10 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. $$
GMZ033-034-182030- 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- 424 AM EDT Fri Sep 18 2026 TODAY Northeast to east winds 5 to 10 knots. Seas 1 to 2 feet. Wave Detail: East 2 feet at 4 seconds. A chance of showers and thunderstorms. TONIGHT Northeast to east winds 5 to 10 knots. Seas around 1 foot. Wave Detail: Northeast to east 1 foot at 4 seconds. Showers likely with a chance of thunderstorms. SATURDAY East winds near 5 knots. Seas 1 foot or less. Wave Detail: East 1 foot at 3 seconds. Showers likely with a chance of thunderstorms. SATURDAY NIGHT East to southeast winds 5 to 10 knots. Seas 1 around 1 foot. A chance of showers and thunderstorms. SUNDAY Southeast to south winds near 5 knots. Seas 1 foot or less. Showers likely with a chance of thunderstorms. SUNDAY NIGHT South to southwest winds near 5 knots, becoming southeast to south. Seas 1 foot or less. A chance of showers and thunderstorms. MONDAY South to southwest winds 5 to 10 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. MONDAY NIGHT South winds 5 to 10 knots. Seas around 1 foot. Showers with a chance of thunderstorms. TUESDAY Southeast to south winds near 5 knots. Seas around 1 foot. Showers and thunderstorms likely. TUESDAY NIGHT Southeast winds 5 to 10 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. $$