886
FZUS52 KKEY 280819
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
419 AM EDT Mon Sep 28 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.

GMZ005-282030-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
419 AM EDT Mon Sep 28 2026

.SYNOPSIS...
A Nor`easter in the New England States will continue to maintain a
lingering northerly swell in our far eastern waters this morning
before subsiding. A weak frontal boundary will lift northward
across the Keys today. This will allow west to northwest winds to
back to the south and southwest during the late morning and
afternoon. Winds will then further back to southeast to south this
evening and eventually more easterly by Tuesday as a high
pressure moves into the eastern U.S. Thereafter, this high will
merge with an existing high pressure across the Atlantic and
subsequently will build. This will promote freshening breezes,
with an increasing likelihood of moderate to fresh breezes for the
latter half of the week.

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.

$$

GMZ031-282030-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
419 AM EDT Mon Sep 28 2026

.TODAY...West to northwest winds near 5 knots, becoming southwest
5 to 10 knots in the afternoon. Bay waters smooth, becoming smooth
to a light chop. A slight chance of showers and thunderstorms.
.TONIGHT...Southwest winds 5 to 10 knots, becoming south to
southwest near 5 knots. Bay waters smooth to a light chop,
becoming smooth. A chance of showers and thunderstorms.
.TUESDAY...Southeast winds 5 to 10 knots. Bay waters smooth to a
light chop. A chance of showers and thunderstorms.
.TUESDAY 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. Showers likely with a chance of thunderstorms.
.WEDNESDAY...Northeast to east winds 10 to 15 knots, increasing to
near 15 knots. Bay waters a light to moderate chop, becoming a
moderate chop. Showers likely with a chance of thunderstorms.
.WEDNESDAY NIGHT...East winds 15 to 20 knots. Bay waters 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 to southeast winds 15 to 20 knots. Bay
waters choppy. Showers likely with a chance of thunderstorms.
.FRIDAY...East to southeast winds near 15 knots. Bay waters a
moderate chop. Showers likely with a chance of thunderstorms.
.FRIDAY NIGHT...East winds 10 to 15 knots. Bay waters a light to
moderate chop. A chance of showers and thunderstorms.

$$

GMZ032-035-282030-
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-
419 AM EDT Mon Sep 28 2026

.TODAY...West winds near 5 knots, becoming south to southwest
this afternoon. Seas 1 foot or less. Nearshore waters smooth. A
slight chance of showers and thunderstorms.
.TONIGHT...Southwest winds 5 to 10 knots, becoming southeast to
south after midnight. Seas 1 foot or less. Nearshore waters
smooth to a light chop, becoming smooth. A chance of showers and
thunderstorms.
.TUESDAY...Southeast winds 5 to 10 knots, except increasing to
near 10 knots west of the Marquesas Keys. Seas 1 foot or less,
building to around 1 foot. West of the Marquesas Keys, seas around
1 foot, building to 1 to 2 feet. Nearshore waters smooth to a
light chop, except becoming a light chop west of the Marquesas
Keys. Showers likely with a chance of thunderstorms.
.TUESDAY NIGHT...Northeast to east winds 5 to 10 knots,
increasing to 10 to 15 knots after midnight. West of the Marquesas
Keys northeast to east winds near 10 knots, increasing to 10 to
15 knots. Seas around 1 foot, except 1 to 2 feet west of the
Marquesas Keys. Nearshore waters smooth to a light chop, becoming
a light to moderate chop. Showers likely with a chance of
thunderstorms.
.WEDNESDAY...Northeast to east winds 10 to 15 knots, becoming east
15 to 20 knots in the afternoon. Seas 1 to 2 feet, except building
to 2 to 3 feet west of the Marquesas Keys. Nearshore waters a
light to moderate chop, becoming choppy. Showers likely with a
chance of thunderstorms.
.WEDNESDAY NIGHT...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 3 to 4 feet, occasionally to 5 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
thunderstorms. Showers likely.
.FRIDAY...East to southeast winds 15 to 20 knots. Seas 2 to
3 feet, except 3 to 5 feet, occasionally to 6 feet west of the
Marquesas Keys. Nearshore waters choppy. Showers likely with a
chance of thunderstorms.
.FRIDAY NIGHT...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.

$$

GMZ042>044-282030-
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-
419 AM EDT Mon Sep 28 2026

.TODAY...West to northwest winds 5 to 10 knots early, briefly
becoming southwest to west near 5 knots, then becoming south to
southwest 5 to 10 knots in the afternoon. Seas 1 foot or less.
Nearshore waters smooth to a light chop. A chance of showers with
a slight chance of thunderstorms.
.TONIGHT...South to southwest winds 5 to 10 knots. Seas around 1
foot. Nearshore waters smooth to a light chop. A chance of
showers and thunderstorms.
.TUESDAY...Southeast winds 5 to 10 knots, increasing to near 10
knots. Seas around 1 foot, building to 1 to 2 feet. Nearshore
waters smooth to a light chop, becoming a light chop. Showers
likely with a chance of thunderstorms.
.TUESDAY NIGHT...Northeast to east winds near 10 knots,
increasing to 10 to 15 knots after midnight. Seas 1 to 2 feet.
Nearshore waters a light chop, becoming a light to moderate chop.
Showers likely with a chance of thunderstorms.
.WEDNESDAY...Northeast to east winds 10 to 15 knots, becoming east
15 to 20 knots in the afternoon. Seas 2 to 3 feet. Nearshore
waters a light to moderate chop, becoming choppy. Showers likely
with a chance of thunderstorms.
.WEDNESDAY NIGHT...East winds 15 to 20 knots. Seas 3 to 5 feet,
occasionally to 6 feet. Nearshore waters choppy. Showers likely
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
likely with a chance of thunderstorms.
.THURSDAY NIGHT...East to southeast winds 15 to 20 knots. Seas
3 to 5 feet, occasionally to 6 feet, except 4 to 6 feet,
occasionally to 8 feet west of Cosgrove Shoal Light. Nearshore
waters choppy. A chance of thunderstorms. Showers likely.
.FRIDAY...East to southeast winds 15 to 20 knots. Seas 3 to
5 feet, occasionally to 6 feet. Nearshore waters choppy. Showers
likely with a chance of thunderstorms.
.FRIDAY NIGHT...East to southeast winds near 15 knots. Seas 3 to
4 feet, occasionally to 5 feet. Nearshore waters a moderate chop.
A chance of showers and thunderstorms.

$$

GMZ052>055-072>075-282030-
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-
419 AM EDT Mon Sep 28 2026

.TODAY...Southwest to west winds 5 to 10 knots, becoming south to
southwest in the afternoon. Seas around 1 foot, except 1 to 2
feet off the Upper Keys due to a northerly swell. Wave Detail:
Northwest 1 foot at 3 seconds. A chance of showers with a slight
chance of thunderstorms.
.TONIGHT...Southwest winds 5 to 10 knots, becoming southeast to
south after midnight. Seas around 1 foot. Wave Detail: South to
southwest 1 foot at 3 seconds. Showers likely with a chance of
thunderstorms.
.TUESDAY...Southeast winds 5 to 10 knots, becoming east to
southeast 10 to 15 knots in the afternoon. Seas around 1 foot,
building to 1 to 2 feet in the afternoon. Wave Detail: East to
southeast 2 feet at 3 seconds. Showers likely with a chance of
thunderstorms.
.TUESDAY NIGHT...East winds 10 to 15 knots, increasing to near 15
knots. Seas around 2 feet, building to 2 to 3 feet. Showers
likely with a chance of thunderstorms.
.WEDNESDAY...East winds near 15 knots, increasing to 15 to 20
knots. Seas 2 to 4 feet, occasionally to 5 feet. Showers likely
with a chance of thunderstorms.
.WEDNESDAY NIGHT...East winds 15 to 20 knots. Seas 3 to 5 feet,
occasionally to 6 feet, building to 5 to 6 feet, occasionally to
8 feet after midnight. Showers likely with a chance of
thunderstorms.
.THURSDAY...East to southeast winds 15 to 20 knots. Seas 5 to 6
feet, occasionally to 8 feet. 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. Showers likely with a chance
of thunderstorms.
.FRIDAY...East to southeast winds 15 to 20 knots, decreasing to
near 15 knots in the afternoon. Seas 4 to 6 feet, occasionally to
8 feet. A chance of showers and thunderstorms.
.FRIDAY NIGHT...East to southeast winds near 15 knots. Seas 4 to
5 feet, occasionally to 6 feet. A chance of showers and
thunderstorms.

$$

GMZ033-034-282030-
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-
419 AM EDT Mon Sep 28 2026

.TODAY...West to northwest winds near 5 knots, becoming south to
southwest in the afternoon. Seas around 1 foot, subsiding to 1 foot
or less. Wave Detail: Northwest 1 foot at 3 seconds. A slight
chance of showers and thunderstorms.
.TONIGHT...South to southwest winds 5 to 10 knots, becoming
southeast to south after midnight. Seas 1 foot or less, building
to around 1 foot. Wave Detail: Southwest 1 foot at 2 seconds. A
chance of showers and thunderstorms.
.TUESDAY...Southeast winds 5 to 10 knots, increasing to 10 to 15
knots in the afternoon. Seas around 1 foot, building to 1 to 2
feet. Wave Detail: South 1 foot at 2 seconds. Showers likely with
a chance of thunderstorms.
.TUESDAY NIGHT...East to southeast winds 10 to 15 knots. Seas
1 to 2 feet. Showers likely with a chance of thunderstorms.
.WEDNESDAY...East winds 10 to 15 knots, increasing to 15 to
20 knots in the afternoon. Seas around 2 feet, building to 2 to 4
feet, occasionally to 5 feet in the afternoon. Showers likely
with a chance of thunderstorms.
.WEDNESDAY NIGHT...East winds 15 to 20 knots. Seas 3 to 5 feet,
occasionally to 6 feet. Showers likely with a chance of
thunderstorms.
.THURSDAY...East to southeast winds 15 to 20 knots. Seas 3 to 5
feet, occasionally to 6 feet. Showers likely with a chance of
thunderstorms.
.THURSDAY NIGHT...East to southeast winds 15 to 20 knots. Seas
4 to 5 feet, occasionally to 6 feet. A chance of thunderstorms.
Showers likely.
.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 near 15 knots. Seas 3 to
4 feet, occasionally to 5 feet. A chance of showers and
thunderstorms.

$$