483
FZUS52 KKEY 301431
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
1031 AM EDT Wed Sep 30 2026

Florida Bay, Hawk Channel and Straits of Florida from Ocean Reef
to south of Dry Tortugas, and the extreme southeastern Gulf of
America, including The Florida Keys National Marine Sanctuary

Seas are given as significant wave height, which is the average
height of the highest 1/3 of the waves. Individual waves may be
more than twice the significant wave height.

The Wave Detail section highlights the period and direction of
origin for the highest-energy waves, as well as any long-period
swells moving in a different direction than the wind.

GMZ005-302030-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
1031 AM EDT Wed Sep 30 2026

.SYNOPSIS...
A high pressure system along the Eastern Seaboard will shift
further offshore and merge with an existing high pressure across
the subtropical Atlantic, and subsequently build through the
remainder of the week. This will promote freshening breezes with
an increasing likelihood of moderate to fresh breezes beginning
Wednesday, continuing through late week. There is a good chance
that marine Cautions may be required for portions of Keys waters
at that time, and Advisories cannot be ruled out. In addition, a
very wet pattern will remain across the Keys over the next few
days, resulting in periods of scattered to numerous showers and
thunderstorms.

The Approximate Shoreward Edge of the Gulf Stream as of
September 25, 2026...

43 NM south of Dry Tortugas Light, on Loggerhead Key
20 NM south of Cosgrove Shoal Light, off the Marquesas Keys
14 NM south of Sand Key Light, off Key West
 7 NM south-southeast of Looe Key, off Big Pine Key
 4 NM south-southeast of Sombrero Key Light, off Marathon
 4 NM south-southeast of Alligator Reef Light, off Islamorada
 0 NM southeast of Molasses Reef Light, off Key Largo
 1 NM west-northwest of Carysfort Reef Light, off Ocean Reef

Gulf Stream Information Courtesy of the Naval Oceanographic Office.

$$

GMZ031-302030-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
1031 AM EDT Wed Sep 30 2026

.THIS AFTERNOON...East winds 10 to 15 knots, becoming east to
southeast near 15 knots. Bay waters a light to moderate chop,
becoming a moderate chop. Showers likely with a chance of
thunderstorms.
.TONIGHT...East winds near 15 knots, increasing to 15 to 20 knots.
Bay waters a moderate chop, becoming choppy. Showers likely with
a chance of thunderstorms.
.THURSDAY...East to southeast winds 15 to 20 knots. Bay waters
choppy. Showers likely with a chance of thunderstorms.
.THURSDAY NIGHT...East winds 15 to 20 knots. Bay waters choppy. A
chance of showers and thunderstorms.
.FRIDAY...East to southeast winds 15 to 20 knots, decreasing to
near 15 knots. Bay waters choppy, becoming a moderate chop. A
chance of showers and thunderstorms.
.FRIDAY NIGHT...East winds near 15 knots. Bay waters a moderate
chop. A chance of showers and thunderstorms.
.SATURDAY...East winds near 15 knots. Bay waters a moderate chop.
A chance of showers and thunderstorms.
.SATURDAY NIGHT...East winds 10 to 15 knots. Bay waters a light
to moderate chop. A slight chance of showers and thunderstorms.
.SUNDAY...East to southeast winds near 10 knots. Bay waters a
light chop. A chance of showers and thunderstorms.
.SUNDAY NIGHT...East to southeast winds near 10 knots. Bay waters
a light chop. A slight chance of showers and thunderstorms.

$$

GMZ032-035-302030-
Bayside and Gulfside from Craig Key to west end of Seven Mile
Bridge-
Gulf of America from west end of Seven Mile Bridge to Halfmoon
Shoal out to 5 Fathoms-
1031 AM EDT Wed Sep 30 2026

.THIS AFTERNOON...East to southeast winds 10 to 15 knots,
increasing to near 15 knots. Seas building to 2 to 3 feet. West
of the Marquesas Keys, seas 2 to 3 feet, building to 3 to 4 feet.
Nearshore waters a moderate chop. Showers likely with a chance of
thunderstorms.
.TONIGHT...East winds 15 to 20 knots. Seas 2 to 3 feet, except
3 to 4 feet, occasionally to 5 feet west of the Marquesas Keys.
Nearshore waters choppy. Showers likely with a chance of
thunderstorms.
.THURSDAY...East to southeast winds 15 to 20 knots. Seas 2 to 3
feet, except 4 to 5 feet, occasionally to 6 feet west of the
Marquesas Keys. Nearshore waters choppy. Showers likely with a
chance of thunderstorms.
.THURSDAY NIGHT...East to southeast winds 15 to 20 knots. Seas
2 to 3 feet, except 4 to 5 feet, occasionally to 6 feet west of
the Marquesas Keys. Nearshore waters choppy. A chance of showers
and thunderstorms.
.FRIDAY...East to southeast winds 15 to 20 knots. Seas 2 to
3 feet, except 3 to 4 feet, occasionally to 5 feet west of the
Marquesas Keys. Nearshore waters choppy. A chance of showers and
thunderstorms.
.FRIDAY NIGHT...East winds 15 to 20 knots, decreasing to near 15
knots. Seas 1 to 2 feet, except 3 to 4 feet, occasionally to 5
feet west of the Marquesas Keys. Nearshore waters choppy, becoming
a moderate chop. A chance of showers and thunderstorms.
.SATURDAY...East to southeast winds near 15 knots. Seas 1 to
3 feet, except 3 to 4 feet, occasionally to 5 feet west of the
Marquesas Keys. Nearshore waters a moderate chop. A chance of
showers and thunderstorms.
.SATURDAY NIGHT...East winds 10 to 15 knots. Seas 1 to 2 feet,
except 2 to 3 feet west of the Marquesas Keys. Nearshore waters a
light to moderate chop. A chance of showers and thunderstorms.
.SUNDAY...East to southeast winds 10 to 15 knots. Seas 1 to
2 feet, except 2 to 3 feet west of the Marquesas Keys. Nearshore
waters a light to moderate chop. A chance of showers and
thunderstorms.
.SUNDAY NIGHT...East to southeast winds near 10 knots. Seas 1 to
2 feet. Nearshore waters a light chop. A slight chance of showers
and thunderstorms.

$$

GMZ042>044-302030-
Hawk Channel from Ocean Reef to Craig Key out to the reef-
Hawk Channel from Craig Key to west end of Seven Mile Bridge out
to the reef-
Hawk Channel from west end of Seven Mile Bridge to Halfmoon Shoal
out to the reef-
1031 AM EDT Wed Sep 30 2026

.THIS AFTERNOON...East winds 10 to 15 knots, becoming east to
southeast near 15 knots. Seas 2 to 4 feet, occasionally to 5
feet. Nearshore waters a light to moderate chop. Showers likely
with a chance of thunderstorms.
.TONIGHT...East winds 15 to 20 knots. Seas 3 to 4 feet,
occasionally to 5 feet. Nearshore waters choppy. Showers with a
chance of thunderstorms.
.THURSDAY...East to southeast winds 15 to 20 knots. Seas 3 to 5
feet, occasionally to 6 feet. Nearshore waters rough. Showers with
a chance of thunderstorms.
.THURSDAY NIGHT...East to southeast winds 15 to 20 knots. Seas 3
to 5 feet, occasionally to 6 feet. Nearshore waters rough. A
chance of showers and thunderstorms.
.FRIDAY...East to southeast winds 15 to 20 knots. Seas 3 to
5 feet, occasionally to 6 feet. Nearshore waters choppy. A chance
of showers and thunderstorms.
.FRIDAY NIGHT...East winds 15 to 20 knots. Seas 3 to 4 feet,
occasionally to 5 feet. Nearshore waters choppy. A chance of
showers and thunderstorms.
.SATURDAY...East to southeast winds 15 to 20 knots. Seas 3 to
4 feet, occasionally to 5 feet. Nearshore waters choppy. A chance
of showers and thunderstorms.
.SATURDAY NIGHT...East winds near 15 knots. Seas 2 to 4 feet,
occasionally to 5 feet. Nearshore waters a moderate chop. A
chance of showers and thunderstorms.
.SUNDAY...East to southeast winds 10 to 15 knots. Seas 2 to
3 feet. Nearshore waters a light to moderate chop. A chance of
showers and thunderstorms.
.SUNDAY NIGHT...East to southeast winds near 10 knots. Seas around
2 feet. Nearshore waters a light chop. A chance of showers and
thunderstorms.

$$

GMZ052>055-072>075-302030-
Straits of Florida from Ocean Reef to Craig Key out 20 NM-
Straits of Florida from Craig Key to west end of Seven Mile
Bridge out 20 NM-
Straits of Florida from west end of Seven Mile Bridge to south of
Halfmoon Shoal out 20 NM-
Straits of Florida from Halfmoon Shoal to 20 NM west of Dry
Tortugas out 20 NM-
Straits of Florida from Ocean Reef to Craig Key 20 to 60 NM out-
Straits of Florida from Craig Key to west end of Seven Mile
Bridge 20 to 60 NM out-
Straits of Florida from west end of Seven Mile Bridge to south of
Halfmoon Shoal 20 to 60 NM out-
Straits of Florida from Halfmoon Shoal to 20 NM west of Dry
Tortugas 20 to 60 NM out-
1031 AM EDT Wed Sep 30 2026

,..SMALL CRAFT ADVISORY MAY BE REQUIRED TONIGHT...

.THIS AFTERNOON...East to southeast winds near 15 knots. Seas 2
to 4 feet, occasionally to 5 feet. Wave Detail: East 4 feet at 5
seconds. Showers likely with a chance of thunderstorms.
.TONIGHT...East to southeast winds 15 to 20 knots, increasing to
near 20 knots. Seas 4 to 6 feet, occasionally to 8 feet. Wave
Detail: East 5 feet at 6 seconds. Showers with a chance of
thunderstorms.
.THURSDAY...East to southeast winds near 20 knots, decreasing to 15
to 20 knots. Seas 5 to 6 feet, occasionally to 8 feet. Wave
Detail: East 6 feet at 6 seconds. Showers likely with a chance of
thunderstorms.
.THURSDAY NIGHT...East to southeast winds 15 to 20 knots. Seas 5
to 6 feet, occasionally to 8 feet. A chance of showers and
thunderstorms.
.FRIDAY...East to southeast winds 15 to 20 knots. Seas 4 to
6 feet, occasionally to 8 feet. A chance of showers and
thunderstorms.
.FRIDAY NIGHT...East winds 15 to 20 knots. Seas 4 to 5 feet,
occasionally to 6 feet. A chance of showers and thunderstorms.
.SATURDAY...East to southeast winds 15 to 20 knots. Seas 4 to 5
feet, occasionally to 6 feet. A chance of showers and thunderstorms.
.SATURDAY NIGHT...East winds near 15 knots. Seas 3 to 4 feet,
occasionally to 5 feet. A chance of showers and thunderstorms.
.SUNDAY...East to southeast winds 10 to 15 knots. Seas 3 to
4 feet, occasionally to 5 feet. A chance of showers and
thunderstorms.
.SUNDAY NIGHT...East to southeast winds near 10 knots. Seas 2 to
3 feet. A chance of showers with a slight chance of
thunderstorms.

$$

GMZ033-034-302030-
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-
1031 AM EDT Wed Sep 30 2026

.THIS AFTERNOON...East to southeast winds 10 to 15 knots,
increasing to near 15 knots. Seas around 2 feet, building to 2 to
4 feet, occasionally to 5 feet. Wave Detail: East to southeast 3
feet at 4 seconds and southwest 1 foot at 5 seconds. Showers
likely with a chance of thunderstorms.
.TONIGHT...East to southeast winds 15 to 20 knots. Seas 3 to
4 feet, occasionally to 5 feet. Wave Detail: East to southeast
4 feet at 5 seconds and southwest 1 foot at 5 seconds. Showers
with a chance of thunderstorms.
.THURSDAY...East to southeast winds 15 to 20 knots. Seas 3 to 5
feet, occasionally to 6 feet. Wave Detail: East to southeast 5
feet at 5 seconds. Showers with a chance of thunderstorms.
.THURSDAY NIGHT...East to southeast winds 15 to 20 knots. Seas 3
to 5 feet, occasionally to 6 feet. Showers likely with a chance of
thunderstorms.
.FRIDAY...East to southeast winds 15 to 20 knots. Seas 3 to
5 feet, occasionally to 6 feet. Showers likely with a chance of
thunderstorms.
.FRIDAY NIGHT...East to southeast winds 15 to 20 knots. Seas 3 to
4 feet, occasionally to 5 feet. A chance of showers and
thunderstorms.
.SATURDAY...East to southeast winds 15 to 20 knots. Seas 3 to
4 feet, occasionally to 5 feet. A chance of showers and
thunderstorms.
.SATURDAY NIGHT...East to southeast winds near 15 knots. Seas 3
to 4 feet, occasionally to 5 feet. A chance of showers and
thunderstorms.
.SUNDAY...East to southeast winds 10 to 15 knots. Seas 2 to
3 feet. A chance of showers and thunderstorms.
.SUNDAY NIGHT...East to southeast winds near 10 knots. Seas 2 to
3 feet. A chance of showers and thunderstorms.

$$