Hazardous marine condition(s):
Short Term Forecast
GMZ005-212215-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
607 AM EDT Mon Sep 21 2026
.SYNOPSIS...
An upper-level low lingers in the eastern Gulf waters through
tonight but will finally lift away from the area on Tuesday.
However, weather conditions will continue to remain unsettled
throughout most of the week as tropical moisture from the
Caribbean spreads northward into the Keys into the middle of the
week. As a result, rain chances will remain elevated with daily
scattered to numerous showers and thunderstorms. The main hazards
that mariners can expect with this activity will be a daily
occurence with gusty winds, lightning strikes, blinding downpours,
and locally hazardous seas. Breezes will generally remain light
to gentle for most of the week but brief periods of moderate
breezes may occur at times, mainly in the evening and overnight
hours. In addition, winds will be out of the south to southeast
throughout most of the week but winds will start to shift more
northerly by late week and into the weekend as a frontal boundary
gradually pushes southward across coastal waters of the Florida
Keys. Seas will also start to build by the end of the week and
into the weekend as northeasterly swell increases in the wake of
the frontal boundary, especially in the Straits of Florida.
The Approximate Shoreward Edge of the Gulf Stream as of September
15, 2026...
64 NM south-southeast of Dry Tortugas Light, on Loggerhead Key
40 NM south-southeast of Cosgrove Shoal Light, off the Marquesas Keys
36 NM south-southeast of Sand Key Light, off Key West
35 NM southeast of Looe Key, off Big Pine Key
28 NM southeast of Sombrero Key Light, off Marathon
15 NM east-southeast of Alligator Reef Light, off Islamorada
8 NM east-southeast of Molasses Reef Light, off Key Largo
5 NM east-southeast of Carysfort Reef Light, off Ocean Reef
Gulf Stream Information Courtesy of the Naval Oceanographic Office.
$$
GMZ033-034-212215- Gulf of America from East Cape Sable to Chokoloskee 20 to 60 NM out and beyond 5 fathoms- Gulf of America including Dry Tortugas and Rebecca Shoal Channel- 607 AM EDT Mon Sep 21 2026 TODAY South to southwest winds 5 to 10 knots. Seas around 1 foot. Wave Detail: South 1 foot at 3 seconds. Showers likely with a chance of thunderstorms. TONIGHT Southeast to south winds 5 to 10 knots. Seas around 1 foot. Wave Detail: Southeast to south 1 foot at 3 seconds. Showers likely with a chance of thunderstorms. TUESDAY South winds 5 to 10 knots. Seas around 1 foot. Wave Detail: Southeast to south 1 foot at 3 seconds. Showers likely with a chance of thunderstorms. TUESDAY NIGHT Southeast to south winds 5 to 10 knots. Seas around 1 foot. Showers with a chance of thunderstorms. WEDNESDAY South winds 5 to 10 knots. Seas around 1 foot. Showers with a chance of thunderstorms. WEDNESDAY NIGHT Southeast to south winds 5 to 10 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. THURSDAY Southeast to south winds near 5 knots. Seas 1 foot or less. Showers likely with a chance of thunderstorms. THURSDAY NIGHT East to southeast winds near 5 knots, becoming north to northeast. Seas 1 foot or less. A chance of showers and thunderstorms. FRIDAY North to northeast winds 5 to 10 knots. Seas 1 to 2 feet. A chance of showers and thunderstorms. FRIDAY NIGHT North to northeast winds 5 to 10 knots. Seas 1 to 2 feet. A chance of showers and thunderstorms. $$
GMZ033-034-212215- 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- 607 AM EDT Mon Sep 21 2026 TODAY South to southwest winds 5 to 10 knots. Seas around 1 foot. Wave Detail: South 1 foot at 3 seconds. Showers likely with a chance of thunderstorms. TONIGHT Southeast to south winds 5 to 10 knots. Seas around 1 foot. Wave Detail: Southeast to south 1 foot at 3 seconds. Showers likely with a chance of thunderstorms. TUESDAY South winds 5 to 10 knots. Seas around 1 foot. Wave Detail: Southeast to south 1 foot at 3 seconds. Showers likely with a chance of thunderstorms. TUESDAY NIGHT Southeast to south winds 5 to 10 knots. Seas around 1 foot. Showers with a chance of thunderstorms. WEDNESDAY South winds 5 to 10 knots. Seas around 1 foot. Showers with a chance of thunderstorms. WEDNESDAY NIGHT Southeast to south winds 5 to 10 knots. Seas around 1 foot. Showers likely with a chance of thunderstorms. THURSDAY Southeast to south winds near 5 knots. Seas 1 foot or less. Showers likely with a chance of thunderstorms. THURSDAY NIGHT East to southeast winds near 5 knots, becoming north to northeast. Seas 1 foot or less. A chance of showers and thunderstorms. FRIDAY North to northeast winds 5 to 10 knots. Seas 1 to 2 feet. A chance of showers and thunderstorms. FRIDAY NIGHT North to northeast winds 5 to 10 knots. Seas 1 to 2 feet. A chance of showers and thunderstorms. $$