Hazardous marine condition(s):
Small Craft Advisory
GMZ005-210830-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
426 PM EDT Tue Oct 20 2026
.SYNOPSIS...
A continental high pressure system centered over southern Canada
will begin to weaken Wednesday, supporting gradually slackening
breezes. Another stronger high pressure system will move in late
week through the weekend, resulting in another period of strong,
potentially near gale breezes during this time frame. A surge of
moisture from the south will also support elevated rain and
thunder chances over the weekend.
The Approximate Shoreward Edge of the Gulf Stream as of October 14,
2026...
7 NM south of Dry Tortugas Light, on Loggerhead Key
4 NM north of Cosgrove Shoal Light, off the Marquesas Keys
3 NM north of Sand Key Light, off Key West
0 NM north-northwest of Looe Key, off Big Pine Key
1 NM southeast of Sombrero Key Light, off Marathon
1 NM south-southeast of Alligator Reef Light, off Islamorada
2 NM northwest of Molasses Reef Light, off Key Largo
2 NM northwest of Carysfort Reef Light, off Ocean Reef
Gulf Stream Information Courtesy of the Naval Oceanographic Office.
$$
GMZ033-034-210830- Gulf of America from East Cape Sable to Chokoloskee 20 to 60 NM out and beyond 5 fathoms- Gulf of America including Dry Tortugas and Rebecca Shoal Channel- 426 PM EDT Tue Oct 20 2026 SMALL CRAFT ADVISORY IN EFFECT TONIGHT Northeast winds 15 to 20 knots, increasing to near 20 knots. Seas 3 to 5 feet, occasionally to 6 feet. Wave Detail: Northeast 4 feet at 5 seconds. A slight chance of showers. WEDNESDAY North to northeast winds near 15 knots, decreasing to 10 to 15 knots. Seas 2 to 4 feet, occasionally to 5 feet, subsiding to 2 to 3 feet. Wave Detail: Northeast 4 feet at 5 seconds. WEDNESDAY NIGHT Northeast winds 10 to 15 knots. Seas 2 to 3 feet. Wave Detail: Northeast 3 feet at 5 seconds. A slight chance of showers. THURSDAY Northeast winds near 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. A slight chance of showers. THURSDAY NIGHT Northeast winds 15 to 20 knots. Seas 3 to 5 feet, occasionally to 6 feet. A slight chance of showers and thunderstorms. FRIDAY Northeast winds 15 to 20 knots, increasing to near 20 knots. Seas 3 to 5 feet, occasionally to 6 feet, building to 4 to 6 feet, occasionally to 8 feet. A slight chance of showers and thunderstorms. FRIDAY NIGHT Northeast winds 20 to 25 knots. Seas 5 to 7 feet, occasionally to 9 feet. A chance of showers with a slight chance of thunderstorms. SATURDAY Northeast winds near 25 knots. Seas 5 to 7 feet, occasionally to 9 feet, building to 6 to 8 feet, occasionally to 10 feet. A chance of showers with a slight chance of thunderstorms. SATURDAY NIGHT Northeast winds 25 to 30 knots. Seas 7 to 10 feet, occasionally to 13 feet. Showers likely with a slight chance of thunderstorms. SUNDAY Northeast winds 25 to 30 knots. Seas 8 to 11 feet, occasionally to 14 feet. Showers likely with a slight chance of thunderstorms. SUNDAY NIGHT Northeast winds 25 to 30 knots. Seas 8 to 11 feet, occasionally to 14 feet. A chance of showers with a slight chance of thunderstorms. $$
GMZ033-034-210830- 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- 426 PM EDT Tue Oct 20 2026 SMALL CRAFT ADVISORY IN EFFECT TONIGHT Northeast winds 15 to 20 knots, increasing to near 20 knots. Seas 3 to 5 feet, occasionally to 6 feet. Wave Detail: Northeast 4 feet at 5 seconds. A slight chance of showers. WEDNESDAY North to northeast winds near 15 knots, decreasing to 10 to 15 knots. Seas 2 to 4 feet, occasionally to 5 feet, subsiding to 2 to 3 feet. Wave Detail: Northeast 4 feet at 5 seconds. WEDNESDAY NIGHT Northeast winds 10 to 15 knots. Seas 2 to 3 feet. Wave Detail: Northeast 3 feet at 5 seconds. A slight chance of showers. THURSDAY Northeast winds near 15 knots. Seas 2 to 4 feet, occasionally to 5 feet. A slight chance of showers. THURSDAY NIGHT Northeast winds 15 to 20 knots. Seas 3 to 5 feet, occasionally to 6 feet. A slight chance of showers and thunderstorms. FRIDAY Northeast winds 15 to 20 knots, increasing to near 20 knots. Seas 3 to 5 feet, occasionally to 6 feet, building to 4 to 6 feet, occasionally to 8 feet. A slight chance of showers and thunderstorms. FRIDAY NIGHT Northeast winds 20 to 25 knots. Seas 5 to 7 feet, occasionally to 9 feet. A chance of showers with a slight chance of thunderstorms. SATURDAY Northeast winds near 25 knots. Seas 5 to 7 feet, occasionally to 9 feet, building to 6 to 8 feet, occasionally to 10 feet. A chance of showers with a slight chance of thunderstorms. SATURDAY NIGHT Northeast winds 25 to 30 knots. Seas 7 to 10 feet, occasionally to 13 feet. Showers likely with a slight chance of thunderstorms. SUNDAY Northeast winds 25 to 30 knots. Seas 8 to 11 feet, occasionally to 14 feet. Showers likely with a slight chance of thunderstorms. SUNDAY NIGHT Northeast winds 25 to 30 knots. Seas 8 to 11 feet, occasionally to 14 feet. A chance of showers with a slight chance of thunderstorms. $$