665
FZUS52 KKEY 120817
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
417 AM EDT Sat Sep 12 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.

GMZ005-122030-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
417 AM EDT Sat Sep 12 2026

.SYNOPSIS...
Ridging across the southeastern United States and Florida will
maintain light to gentle east to southeasterly breezes over the
next few days. Low level moisture will remain abundant and keep
convective potential slightly above normal today, but fall back to
near normal early in the week as drier lower levels filter in.
The ridge will be reinforced late in the forecast and may drive
freshening northeast to easterly breezes.

The Approximate Shoreward Edge of the Gulf Stream as of September
11, 2026...

26 NM south of Dry Tortugas Light, on Loggerhead Key
15 NM south of Cosgrove Shoal Light, off the Marquesas Keys
15 NM south of Sand Key Light, off Key West
11 NM south-southeast of Looe Key, off Big Pine Key
 8 NM southeast of Sombrero Key Light, off Marathon
 6 NM southeast of Alligator Reef Light, off Islamorada
 2 NM southeast of Molasses Reef Light, off Key Largo
 1 NM east-southeast of Carysfort Reef Light, off Ocean Reef

Gulf Stream Information Courtesy of the National Weather Service in
Key West, using data from RTOFS and NASA SPoRT SST.

$$

GMZ031-122030-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
417 AM EDT Sat Sep 12 2026

.TODAY...East to southeast winds near 10 knots, decreasing to near
5 knots. Bay waters a light chop, becoming smooth. A chance of
showers and thunderstorms.
.TONIGHT...East to southeast winds near 5 knots. Bay waters
smooth. A chance of showers and thunderstorms.
.SUNDAY...Southeast to south winds near 5 knots. Bay waters
smooth. A chance of showers and thunderstorms.
.SUNDAY NIGHT...East winds near 5 knots. Bay waters smooth. A
chance of showers and thunderstorms.
.MONDAY...East winds near 5 knots. Bay waters smooth. A chance of
showers and thunderstorms.
.MONDAY NIGHT...Northeast to east winds 5 to 10 knots, increasing
to near 10 knots. Bay waters smooth to a light chop, becoming a
light chop. A chance of showers and thunderstorms.
.TUESDAY...Northeast to east winds 5 to 10 knots, increasing to
10 to 15 knots. Bay waters smooth to a light chop, becoming a
light to moderate chop. Showers likely with a chance of
thunderstorms.
.TUESDAY NIGHT...Northeast to east winds near 15 knots. Bay
waters a moderate chop. A chance of showers and thunderstorms.
.WEDNESDAY...Northeast to east winds 10 to 15 knots. Bay waters a
light to moderate chop. Showers with a chance of thunderstorms.
.WEDNESDAY NIGHT...Northeast to east winds 15 to 20 knots,
decreasing to 10 to 15 knots. Bay waters choppy, becoming light
to moderate chop. Showers likely with a chance of thunderstorms.

$$

GMZ032-035-122030-
Bayside and Gulf side from Craig Key to west end of Seven Mile
Bridge-
Gulf of Mexico from west end of Seven Mile Bridge to Halfmoon
Shoal out to 5 Fathoms-
417 AM EDT Sat Sep 12 2026

.TODAY...Southeast winds near 10 knots, decreasing to 5 knots.
Seas 1 foot or less. Nearshore waters a light chop, becoming
smooth. A chance of showers and thunderstorms.
.TONIGHT...East to southeast winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. A chance of showers and
thunderstorms.
.SUNDAY...Southeast winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth. A chance of showers and thunderstorms.
.SUNDAY NIGHT...East winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth. A chance of showers and thunderstorms.
.MONDAY...East winds near 5 knots. Seas 1 foot or less. Nearshore
waters smooth. A chance of showers and thunderstorms.
.MONDAY NIGHT...East winds 5 to 10 knots, increasing to near 10
knots. Seas around 1 foot. Nearshore waters smooth to a light
chop, becoming a light chop. A chance of showers and
thunderstorms.
.TUESDAY...East winds 10 to 15 knots. Seas around 1 foot.
Nearshore waters a light to moderate chop. Showers likely with a
chance of thunderstorms.
.TUESDAY NIGHT...Northeast to east winds near 15 knots. Seas 1 to
2 feet. Nearshore waters a moderate chop. A chance of showers and
thunderstorms.
.WEDNESDAY...Northeast to east winds 10 to 15 knots. Seas 1 to
2 feet. Nearshore waters a light to moderate chop. Showers with a
chance of thunderstorms.
.WEDNESDAY NIGHT...Northeast to east winds 15 to 20 knots,
decreasing to 10 to 15 knots after midnight. Seas 1 to 3 feet.
Nearshore waters choppy, becoming light to moderate chop. Showers
with a chance of thunderstorms.

$$

GMZ042>044-122030-
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 AM EDT Sat Sep 12 2026

.TODAY...Southeast winds near 10 knots, becoming east near 5
knots. Seas around 1 foot. Nearshore waters a light chop, becoming
smooth. A chance of showers and thunderstorms.
.TONIGHT...East to southeast winds 5 to 10 knots. Seas around 1
foot. Nearshore waters smooth to a light chop. A chance of showers
and thunderstorms.
.SUNDAY...Southeast to south winds near 5 knots, becoming east in
the afternoon. Seas 1 foot or less. Nearshore waters smooth. A
chance of showers and thunderstorms.
.SUNDAY NIGHT...East winds 5 to 10 knots. Seas 1 foot or less.
Nearshore waters smooth to a light chop. A chance of showers and
thunderstorms.
.MONDAY...East winds near 5 knots. Seas around 1 foot. Nearshore
waters smooth. A chance of showers and thunderstorms.
.MONDAY NIGHT...East winds 5 to 10 knots, increasing to near 10
knots. Seas around 1 foot. Nearshore waters smooth to a light
chop, becoming a light chop. A chance of showers and
thunderstorms.
.TUESDAY...East winds 10 to 15 knots. Seas 1 to 2 feet. Nearshore
waters a light to moderate chop. A chance of showers and
thunderstorms.
.TUESDAY NIGHT...Northeast to east winds near 15 knots. Seas 2 to
3 feet. Nearshore waters a moderate chop. Showers likely with a
chance of thunderstorms.
.WEDNESDAY...Northeast to east winds 10 to 15 knots. Seas 2 to
3 feet. Nearshore waters a light to moderate chop. Showers with a
chance of thunderstorms.
.WEDNESDAY NIGHT...Northeast to east winds 15 to 20 knots,
decreasing to 10 to 15 knots. Seas 2 to 3 feet. Nearshore waters
choppy, becoming a light to moderate chop. Showers with a chance
of thunderstorms.

$$

GMZ052>055-072>075-122030-
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 AM EDT Sat Sep 12 2026

.TODAY...Southeast winds 10 to 15 knots, becoming east 5 to 10
knots. Seas 1 to 2 feet. Wave Detail: East to southeast 2 feet at
4 seconds. A chance of showers and thunderstorms.
.TONIGHT...Southeast winds 5 to 10 knots. Seas around 1 foot.
Wave Detail: East to southeast 1 foot at 4 seconds. A chance of
showers and thunderstorms.
.SUNDAY...Southeast to south winds near 5 knots, becoming
northeast to east in the afternoon. Seas around 1 foot. Wave
Detail: East to southeast 1 foot at 4 seconds. A slight chance of
showers and thunderstorms.
.SUNDAY NIGHT...East winds 5 to 10 knots. Seas around 1 foot. A
chance of showers and thunderstorms.
.MONDAY...East winds 5 to 10 knots. Seas around 1 foot. A slight
chance of showers and thunderstorms.
.MONDAY NIGHT...East winds near 10 knots. Seas 1 to 2 feet. A
chance of showers and thunderstorms.
.TUESDAY...East winds 10 to 15 knots. Seas 1 to 2 feet. A chance
of showers and thunderstorms.
.TUESDAY NIGHT...Northeast to east winds near 15 knots. Seas 2 to
3 feet. Showers likely with a chance of thunderstorms.
.WEDNESDAY...Northeast to east winds 10 to 15 knots. Seas around
2 to 3 feet. Showers with a chance of thunderstorms.
.WEDNESDAY NIGHT...Northeast to east winds near 15 knots,
decreasing to 10 to 15 knots. Seas 2 to 4 feet. Showers likely
with a chance of thunderstorms.


$$

GMZ033-034-122030-
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 AM EDT Sat Sep 12 2026

.TODAY...Southeast winds near 10 knots, becoming northeast to
east near around 5 knots. Seas 1 foot or less. Wave Detail:
Southeast 1 foot at 3 seconds. A chance of showers and
thunderstorms.
.TONIGHT...Northeast to east winds near 5 knots, becoming
southeast. Seas 1 foot or less. Wave Detail: East 1 foot at 3
seconds. A chance of showers and thunderstorms.
.SUNDAY...Variable winds near 5 knots, becoming north to
northeast around 5 knots in the afternoon. Seas 1 foot or less. A
chance of showers and thunderstorms.
.SUNDAY NIGHT...Northeast to east winds near 5 knots. Seas 1 foot
or less. A chance of showers and thunderstorms.
.MONDAY...Northeast to east winds near 5 knots. Seas 1 foot or
less. A chance of showers and thunderstorms.
.MONDAY NIGHT...Northeast to east winds 5 to 10 knots. Seas
around 1 foot. Showers likely with a chance of thunderstorms.
.TUESDAY...Northeast to east winds 5 to 10 knots. Seas around
1 foot. Showers likely with a chance of thunderstorms.
.TUESDAY NIGHT...Northeast to east winds near 10 knots, increasing
to near 15 knots. Seas building to around 2 feet. Showers likely
with a chance of thunderstorms.
.WEDNESDAY...Northeast to east winds 10 to 15 knots. Seas 2 to
3 feet. Thunderstorms likely. Showers.
.WEDNESDAY NIGHT...Northeast to east winds 15 to 20 knots,
decreasing to near 15 knots. Seas 2 to 3 feet. Showers with a
chance of thunderstorms.

$$