487
FZUS52 KKEY 302017
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
417 PM 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.

GMZ005-010830-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
417 PM EDT Wed Sep 30 2026

.SYNOPSIS...
High pressure offshore the Eastern Seaboard will merge with an
existing high pressure across the subtropical Atlantic, and
subsequently build through the remainder of the week. Breezes will
increase, becoming moderate to fresh tonight and continuing
through late week. Widespread exercise caution headlines will be
necesary through at least Friday, with Small Craft Advisories
likely required the Straits of Florida. In addition, a very wet
pattern will remain across the Keys over the next couple 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.

$$

GMZ031-010830-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
417 PM EDT Wed Sep 30 2026

...SMALL CRAFT SHOULD EXERCISE CAUTION FOR INCREASING WINDS...

.TONIGHT...East winds 10 to 15 knots, increasing to 15 to 20
knots. Bay waters a light to 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 AND 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.
.MONDAY...Southeast winds 5 to 10 knots. Bay waters smooth to a
light chop. A chance of showers and thunderstorms.
.MONDAY NIGHT...Southeast winds near 5 knots. Bay waters smooth.
A slight chance of showers and thunderstorms.

$$

GMZ032-035-010830-
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-
417 PM EDT Wed Sep 30 2026

...SMALL CRAFT SHOULD EXERCISE CAUTION...

.TONIGHT...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. Showers 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 around 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
2 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
around 1 foot. Nearshore waters a light chop. A slight chance of
showers and thunderstorms.
.MONDAY...Southeast winds 5 to 10 knots. Seas 1 foot or less.
Nearshore waters smooth to a light chop. A chance of showers and
thunderstorms.
.MONDAY NIGHT...Southeast winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. A slight chance of showers and
thunderstorms.

$$

GMZ042>044-010830-
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-
417 PM EDT Wed Sep 30 2026

...SMALL CRAFT SHOULD EXERCISE CAUTION...
...SMALL CRAFT ADVISORY MAY BE REQUIRED THURSDAY...

.TONIGHT...East to southeast winds 15 to 20 knots. Seas 2 to
4 feet, occasionally to 5 feet. Nearshore waters choppy. Showers
with a chance of thunderstorms.
.THURSDAY...East to southeast winds near 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 near 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 light to 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 1 to
2 feet. Nearshore waters a light chop. A chance of showers and
thunderstorms.
.MONDAY...Southeast winds near 10 knots. Seas 1 to 2 feet.
Nearshore waters smooth to a light chop. A chance of showers and
thunderstorms.
.MONDAY NIGHT...Southeast winds 5 to 10 knots. Seas around 1
foot. Nearshore waters smooth. A slight chance of showers and
thunderstorms.

$$

GMZ052>055-072>075-010830-
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-
417 PM EDT Wed Sep 30 2026

...SMALL CRAFT ADVISORY IN EFFECT...

.TONIGHT...East to southeast winds 15 to 20 knots, increasing to
near 20 knots. Seas 3 to 5 feet, occasionally to 6 feet,
increasing to 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 to southeast 6 feet at 6 seconds. Showers likely
with a chance of thunderstorms.
.THURSDAY NIGHT...East to southeast winds near 20 knots. Seas
5 to 6 feet, occasionally to 8 feet. Wave Detail: East 5 feet at
6 seconds. 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 around
4 feet, occasionally to 5 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 2 to
3 feet. A chance of showers and thunderstorms.
.SUNDAY NIGHT...East to southeast winds near 10 knots. Seas
around 2 feet. A chance of showers with a slight chance of
thunderstorms.
.MONDAY...Southeast winds near 10 knots. Seas around 2 feet. A
chance of showers and thunderstorms.
.MONDAY NIGHT...Southeast winds 5 to 10 knots. Seas 1 to 2 feet.
A chance of showers and thunderstorms.

$$

GMZ033-034-010830-
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-
417 PM EDT Wed Sep 30 2026

...SMALL CRAFT SHOULD EXERCISE CAUTION...

.TONIGHT...East to southeast winds 15 to 20 knots. Seas 2 to
4 feet, occasionally to 5 feet. Wave Detail: East to southeast
4 feet at 4 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. Wave Detail: East to southeast
5 feet at 5 seconds. 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 AND 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 2
to 3 feet. A chance of showers and thunderstorms.
.SUNDAY...East to southeast winds 10 to 15 knots. Seas 2 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 and thunderstorms.
.MONDAY AND MONDAY NIGHT...Southeast winds 5 to 10 knots. Seas 1
to 2 feet. A chance of showers and thunderstorms.

$$