GMZ005-220930-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
430 PM EST Wed Jan 21 2026
.SYNOPSIS...A broad high pressure system located just off the
Mid-Atlantic will continue slowly weaken as it slides further
eastward through the rest of the work week. Breezes will slacken
as the pressure gradient weakens, and gentle to moderate breezes
are expected across the nearshore and offshore waters for Thursday
through Saturday, becoming light to gentle for Sunday. A strong
winter storm will impact the Southeast over the weekend, driving a
strong frontal boundary through the Keys marine zones Monday
afternoon and evening. Winds will clock around to the north in its
wake for early next week, becoming fresh to strong.
The Approximate Shoreward Edge of the Gulf Stream as of January
18...
18 NM South of Dry Tortugas Light...on Loggerhead Key.
16 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
15 NM South of Sand Key Light...off Key West.
13 NM South of Looe Key...off Big Pine Key.
13 NM Southeast of Sombrero Key Light...off Marathon.
12 NM Southeast of Alligator Reef Light...off Islamorada.
7 NM Southeast of Molasses Reef Light...off Key Largo.
4 NM Southeast of Carysfort Reef Light...off Ocean Reef.
Gulf Stream Information Courtesy of the National Weather Service in
Key West based on products from NASA SPoRT and RTOFS.
$$
GMZ031-220930- Florida Bay including Barnes Sound, Blackwater Sound, and Buttonwood Sound- 430 PM EST Wed Jan 21 2026 SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL WINDS DECREASE TONIGHT Northeast winds 15 to 20 knots, decreasing to 10 to 15 knots. Bay waters choppy, becoming a light to moderate chop. Scattered showers. THURSDAY Northeast to east winds 10 to 15 knots, decreasing to near 10 knots. Bay waters a light to moderate chop, becoming a light chop. Scattered showers. THURSDAY NIGHT Northeast to east winds near 10 knots. Bay waters a light chop. Isolated showers. FRIDAY AND FRIDAY NIGHT Northeast to east winds 5 to 10 knots. Bay waters smooth to a light chop. Isolated showers. SATURDAY East winds near 10 knots. Bay waters a light chop. Isolated showers. SATURDAY NIGHT East to southeast winds near 10 knots. Bay waters a light chop. SUNDAY East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop. SUNDAY NIGHT Southeast to south winds near 5 knots, becoming variable. Bay waters smooth. MONDAY Variable winds near 5 knots, becoming west to northwest and increasing to near 10 knots. Bay waters smooth, becoming a light chop. Isolated showers. MONDAY NIGHT Northwest to north winds near 10 knots, increasing to near 15 knots. Bay waters a light chop, becoming a moderate chop. Isolated showers. $$
GMZ031-220930- Florida Bay including Barnes Sound, Blackwater Sound, and Buttonwood Sound- 430 PM EST Wed Jan 21 2026 SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL WINDS DECREASE TONIGHT Northeast winds 15 to 20 knots, decreasing to 10 to 15 knots. Bay waters choppy, becoming a light to moderate chop. Scattered showers. THURSDAY Northeast to east winds 10 to 15 knots, decreasing to near 10 knots. Bay waters a light to moderate chop, becoming a light chop. Scattered showers. THURSDAY NIGHT Northeast to east winds near 10 knots. Bay waters a light chop. Isolated showers. FRIDAY AND FRIDAY NIGHT Northeast to east winds 5 to 10 knots. Bay waters smooth to a light chop. Isolated showers. SATURDAY East winds near 10 knots. Bay waters a light chop. Isolated showers. SATURDAY NIGHT East to southeast winds near 10 knots. Bay waters a light chop. SUNDAY East to southeast winds 5 to 10 knots. Bay waters smooth to a light chop. SUNDAY NIGHT Southeast to south winds near 5 knots, becoming variable. Bay waters smooth. MONDAY Variable winds near 5 knots, becoming west to northwest and increasing to near 10 knots. Bay waters smooth, becoming a light chop. Isolated showers. MONDAY NIGHT Northwest to north winds near 10 knots, increasing to near 15 knots. Bay waters a light chop, becoming a moderate chop. Isolated showers. $$