GMZ005-212030-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
431 AM EDT Wed Oct 21 2026
.SYNOPSIS...
A continental high pressure system centered over southern Canada
will begin to weaken today, accompanied by slackening breezes.
Another high pressure system will develop over the Eastern
Seaboard Friday and Friday night. Meanwhile, a broad low pressure
system will begin to fester near the southeastern Bahamas. The
resulting pattern likely will result in strong, to potentially
near gale breezes by Sunday or Sunday night. The freshening
breezes and a surge of moisture will support elevated rain and
thunder chances over the weekend.
The Approximate Shoreward Edge of the Gulf Stream as of October
19, 2026...
46 NM south of Dry Tortugas Light, on Loggerhead Key
18 NM north of Cosgrove Shoal Light, off the Marquesas Keys
12 NM north of Sand Key Light, off Key West
7 NM north-northwest of Looe Key, off Big Pine Key
5 NM southeast of Sombrero Key Light, off Marathon
2 NM south-southeast of Alligator Reef Light, off Islamorada
2 NM northwest of Molasses Reef Light, off Key Largo
3 NM northwest of Carysfort Reef Light, off Ocean Reef
Gulf Stream Information Courtesy of the Naval Oceanographic
Office.
$$
GMZ033-034-212030- 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- 431 AM EDT Wed Oct 21 2026 SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL WINDS DECREASE TODAY Northeast winds 15 to 20 knots, becoming north to northeast and decreasing to 10 to 15 knots this afternoon. Seas 3 to 5 feet, occasionally to 6 feet, subsiding to 2 to 3 feet. Wave Detail: Northeast 4 feet at 5 seconds. TONIGHT North to northeast winds 10 to 15 knots, becoming northeast and increasing to 15 to 20 knots after midnight. Seas 2 to 4, occasionally to 5 feet. Wave Detail: Northeast 3 feet at 5 seconds. A slight chance of showers. THURSDAY Northeast winds near 15 knots, becoming north to northeast and decreasing to 10 to 15 knots. Seas 2 to 3 feet. Wave Detail: Northeast 3 feet at 5 seconds. THURSDAY NIGHT North to northeast winds near 15 knots, becoming northeast and increasing to 15 to 20 knots. Seas 2 to 4 feet, occasionally to 5 feet. A slight chance of showers and thunderstorms. FRIDAY Northeast winds 15 to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. A slight chance of showers and thunderstorms. FRIDAY NIGHT Northeast winds near 20 knots, increasing to 20 to 25 knots. Seas building to 4 to 6 feet, occasionally to 8 feet. A chance of showers with a slight chance of thunderstorms. SATURDAY Northeast winds 20 to 25 knots. Seas 4 to 7 feet, occasionally to 9 feet. A chance of showers and thunderstorms. SATURDAY NIGHT Northeast winds 20 to 25 knots, increasing to 25 to 30 knots after midnight. Seas 5 to 8 feet, occasionally to 10 feet, building to 7 to 10 feet, occasionally to 13 feet. A chance of showers 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. $$
GMZ033-034-212030- 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- 431 AM EDT Wed Oct 21 2026 SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL WINDS DECREASE TODAY Northeast winds 15 to 20 knots, becoming north to northeast and decreasing to 10 to 15 knots this afternoon. Seas 3 to 5 feet, occasionally to 6 feet, subsiding to 2 to 3 feet. Wave Detail: Northeast 4 feet at 5 seconds. TONIGHT North to northeast winds 10 to 15 knots, becoming northeast and increasing to 15 to 20 knots after midnight. Seas 2 to 4, occasionally to 5 feet. Wave Detail: Northeast 3 feet at 5 seconds. A slight chance of showers. THURSDAY Northeast winds near 15 knots, becoming north to northeast and decreasing to 10 to 15 knots. Seas 2 to 3 feet. Wave Detail: Northeast 3 feet at 5 seconds. THURSDAY NIGHT North to northeast winds near 15 knots, becoming northeast and increasing to 15 to 20 knots. Seas 2 to 4 feet, occasionally to 5 feet. A slight chance of showers and thunderstorms. FRIDAY Northeast winds 15 to 20 knots. Seas 3 to 4 feet, occasionally to 5 feet. A slight chance of showers and thunderstorms. FRIDAY NIGHT Northeast winds near 20 knots, increasing to 20 to 25 knots. Seas building to 4 to 6 feet, occasionally to 8 feet. A chance of showers with a slight chance of thunderstorms. SATURDAY Northeast winds 20 to 25 knots. Seas 4 to 7 feet, occasionally to 9 feet. A chance of showers and thunderstorms. SATURDAY NIGHT Northeast winds 20 to 25 knots, increasing to 25 to 30 knots after midnight. Seas 5 to 8 feet, occasionally to 10 feet, building to 7 to 10 feet, occasionally to 13 feet. A chance of showers 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. $$