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Cow Key Channel, FL Coastal Forecast

FZUS52 KKEY 172123
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
423 PM EST Wed Dec 17 2025

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.

Wave Detail will include details about the period and direction
of origin for the highest energy waves. Long-period swells coming
from a different direction than the wind would be included in the
Wave Detail.

GMZ005-180930-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
423 PM EST Wed Dec 17 2025

.SYNOPSIS...High pressure extending along the southern end of the
Eastern Seaboard into the western North Atlantic will continue to
promote moderate to fresh northeast to east breezes tonight.
Breezes will slacken during the second half of the week while the
high slides into the central North Atlantic. A second, weaker
front will push through the Florida Keys coastal waters by the end
of the week, with modestly freshened breezes expected for the
weekend behind the front. Another high building over the eastern
CONUS this weekend will be sufficient to generate fresh to strong
breezes early next week.

The Approximate Shoreward Edge of the Gulf Stream as of December 15...

26 NM South of Dry Tortugas Light...on Loggerhead Key.
21 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
15 NM South of Sand Key Light...off Key West.
18 NM South of Looe Key...off Big Pine Key.
16 NM Southeast of Sombrero Key Light...off Marathon.
13 NM Southeast of Alligator Reef Light...off Islamorada.
7 NM Southeast of Molasses Reef Light...off Key Largo.
3 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.

$$

GMZ031-180930-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
423 PM EST Wed Dec 17 2025

.TONIGHT...East winds 10 to 15 knots. Bay waters a light to
moderate chop.
.THURSDAY...East to southeast winds 10 to 15 knots. Bay waters a
light to moderate chop. Scattered showers.
.THURSDAY NIGHT...Southeast winds near 10 knots, becoming south
to southwest. Bay waters a light chop. Scattered showers and
isolated thunderstorms.
.FRIDAY...Southwest to west near 10 knots, becoming northwest.
Bay waters a light chop. Isolated showers.
.FRIDAY NIGHT...Northwest to north winds near 10 knots, becoming
north to northeast. Bay waters a light chop.
.SATURDAY...Northeast winds near 10 knots. Bay waters a light
chop.
.SATURDAY NIGHT...Northeast to east winds near 10 knots. Bay
waters a light chop.
.SUNDAY...Northeast to east winds near 10 knots. Bay waters a
light chop. Isolated showers.
.SUNDAY NIGHT...Northeast winds 10 to 15 knots. Bay waters a
light to moderate chop. Isolated showers.
.MONDAY...Northeast winds near 15 knots, becoming northeast to
east 15 to 20 knots. Bay waters a moderate chop, becoming choppy.
Isolated showers.
.MONDAY NIGHT...Northeast to east winds 15 to 20 knots. Bay
waters choppy. Isolated showers.

$$

GMZ032-035-180930-
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-
423 PM EST Wed Dec 17 2025

.TONIGHT...East winds 10 to 15 knots, increasing to near 15 knots.
Seas 2 to 3 feet, except 3 to 4 feet, occasionally to 5 feet west
of the Marquesas Keys. Nearshore waters a light to moderate chop,
becoming a moderate chop. Isolated showers.
.THURSDAY...East to southeast winds decreasing to 10 to 15 knots.
Seas subsiding to 1 to 2 feet, except subsiding to 2 to 3 feet
west of the Marquesas Keys. Nearshore waters becoming a light to
moderate chop. Scattered showers.
.THURSDAY NIGHT...Southeast winds near 10 knots, becoming south
to southwest. Seas 1 to 2 feet, except around 2 feet west of the
Marquesas Keys. Nearshore waters a light chop. Scattered showers
and isolated thunderstorms.
.FRIDAY...Southwest winds 5 to 10 knots, becoming northwest near
10 knots. Seas subsiding to around 1 foot. Nearshore waters
smooth to a light chop, becoming a light chop. Isolated showers.
.FRIDAY NIGHT...North winds 10 to 15 knots. Seas 1 to 2 feet.
Nearshore waters a light to moderate chop.
.SATURDAY...Northeast winds 10 to 15 knots, decreasing to near 10
knots. Seas 1 to 2 feet. Nearshore waters a light to moderate
chop, becoming a light chop.
.SATURDAY NIGHT...Northeast to east winds near 10 knots. Seas 1
to 2 feet. Nearshore waters a light chop.
.SUNDAY...Northeast to east winds near 10 knots. Seas 1 to
2 feet. Nearshore waters a light chop. Isolated showers.
.SUNDAY NIGHT...Northeast winds 10 to 15 knots. Seas 1 to 2 feet.
Nearshore waters a light to moderate chop.
.MONDAY...Northeast winds near 15 knots, increasing to 15 to 20
knots. Seas 1 to 2 feet, building to 2 to 3 feet. West of the
Marquesas Keys, seas around 2 feet, building 3 to 4 feet,
occasionally to 5 feet. Nearshore waters a moderate chop,
becoming choppy. Isolated showers.
.MONDAY NIGHT...Northeast to east winds 15 to 20 knots. Seas 2 to
3 feet, except 3 to 4 feet, occasionally to 5 feet. Nearshore
waters choppy. Isolated showers.

$$

GMZ042>044-180930-
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-
423 PM EST Wed Dec 17 2025

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

.TONIGHT...East winds near 15 knots, increasing to 15 to 20
knots. Seas 3 to 4 feet, occasionally to 5 feet. Nearshore waters
a moderate chop, becoming choppy. Isolated showers.
.THURSDAY...East to southeast winds decreasing to near 15 knots.
Seas 2 to 4 feet, occasionally to 5 feet. Nearshore waters becoming
a moderate chop. Scattered showers.
.THURSDAY NIGHT...Southeast to south winds 10 to 15 knots,
becoming south to southwest near 10 knots. Seas 2 to 3 feet.
Nearshore waters a light to moderate chop, becoming a light chop.
Scattered showers and isolated thunderstorms.
.FRIDAY...West to northwest winds near 10 knots. Seas 1 to 2
feet. Nearshore waters a light chop. Isolated showers.
.FRIDAY NIGHT...Northwest to north winds 10 to 15 knots. Seas 1
to 3 feet. Nearshore waters a light to moderate chop.
.SATURDAY...North to northeast winds 10 to 15 knots. Seas 1 to 3
feet. Nearshore waters a light to moderate chop.
.SATURDAY NIGHT...Northeast to east winds near 10 knots. Seas
1 to 2 feet. Nearshore waters a light chop.
.SUNDAY...Northeast to east winds near 10 knots. Seas 1 to
3 feet. Nearshore waters a light chop. Isolated showers.
.SUNDAY NIGHT...Northeast winds 10 to 15 knots. Seas 2 to 3 feet.
Nearshore waters a light to moderate chop. Isolated showers.
.MONDAY...Northeast winds near 15 knots, increasing to 15 to 20
knots. Seas building to 2 to 4 feet, occasionally to 5 feet.
Nearshore waters a moderate chop, becoming choppy. Isolated
showers.
.MONDAY NIGHT...Northeast to east winds near 20 knots. Seas 3 to
4 feet, occasionally to 5 feet. Nearshore waters rough. Isolated
showers.

$$

GMZ052>055-072>075-180930-
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-
423 PM EST Wed Dec 17 2025

...SMALL CRAFT SHOULD EXERCISE CAUTION...

.TONIGHT...East winds 15 to 20 knots. Seas 4 to 6 feet,
occasionally to 8 feet. Wave Detail: East 6 feet at 6 seconds.
Isolated showers.
.THURSDAY...East to southeast winds 15 to 20 knots, decreasing to
near 15 knots. Seas 4 to 6 feet, occasionally to 8 feet. Wave
Detail: East to southeast 6 feet at 6 seconds. Scattered showers.
.THURSDAY NIGHT...Southeast to south winds 10 to 15 knots,
becoming south to southwest near 10 knots. Seas 3 to 5 feet,
occasionally to 6 feet, subsiding to 2 to 4 feet, occasionally to
5 feet. Wave Detail: East to southeast 4 feet at 6 seconds.
Scattered showers and isolated thunderstorms.
.FRIDAY...Southwest to west winds near 10 knots, becoming
northwest. Seas around 2 feet. Isolated showers.
.FRIDAY NIGHT...North winds 10 to 15 knots. Seas around 2 feet.
Isolated showers.
.SATURDAY...Northeast winds 10 to 15 knots. Seas 2 to 3 feet.
Isolated showers.
.SATURDAY NIGHT...Northeast to east winds near 10 knots. Seas
2 to 3 feet. Isolated showers.
.SUNDAY...Northeast to east winds 10 to 15 knots. Seas 2 to
3 feet. Isolated showers.
.SUNDAY NIGHT...Northeast to east winds near 15 knots. Seas 3 to
4 feet, occasionally to 5 feet. Isolated showers.
.MONDAY...Northeast to east winds 15 to 20 knots. Seas 4 to
6 feet, occasionally to 8 feet. Isolated showers.
.MONDAY NIGHT...Northeast to east winds near 20 knots. Seas 5 to
7 feet, occasionally to 9 feet. Isolated showers.

$$

GMZ033-034-180930-
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-
423 PM EST Wed Dec 17 2025

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

.TONIGHT...East winds near 15 knots, increasing to 15 to 20
knots. Seas 3 to 4 feet, occasionally to 5 feet. Wave Detail:
East 4 feet at 4 seconds. Isolated showers.
.THURSDAY...East to southeast winds near 15 knots, decreasing to
10 to 15 knots. Seas 2 to 4 feet, occasionally to 5 feet,
subsiding to 2 to 3 feet. Wave Detail: East to southeast 4 feet
at 4 seconds. Scattered showers.
.THURSDAY NIGHT...Southeast to south winds near 10 knots,
becoming south to southwest. Seas subsiding to 1 to 2 feet. Wave
Detail: Southeast to south 2 feet at 4 seconds. Scattered showers
and isolated thunderstorms.
.FRIDAY...West winds 5 to 10 knots, becoming northwest near 10
knots. Seas 1 to 2 feet. Isolated showers.
.FRIDAY NIGHT...North winds 10 to 15 knots. Seas around 2 feet.
.SATURDAY...Northeast winds 10 to 15 knots, becoming northeast to
east near 10 knots. Seas 2 to 3 feet.
.SATURDAY NIGHT...Northeast to east winds near 10 knots. Seas
around 2 feet.
.SUNDAY...Northeast winds near 10 knots. Seas around 2 feet.
Isolated showers.
.SUNDAY NIGHT...Northeast winds 10 to 15 knots. Seas 2 to 3 feet.
.MONDAY...Northeast winds near 15 knots, increasing to 15 to 20
knots. Seas 2 to 3 feet, building to 3 to 4 feet, occasionally to
5 feet. Isolated showers.
.MONDAY NIGHT...Northeast to east winds 15 to 20 knots. Seas 3 to
5 feet, occasionally to 6 feet.

$$


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