Coastal Waters Forecast
Issued by NWS Key West, FL

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511
FZUS52 KKEY 170817
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
417 AM EDT Fri Oct 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.

GMZ005-172030-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
417 AM EDT Fri Oct 17 2025

.SYNOPSIS...A high pressure system moving towards the southeastern
CONUS form the Great Lakes will support breezes freshening to
moderate to fresh today and tonight. Small Craft Advisories may
be required as breezes are expected to be just below the
threshold. Shower coverage will rise today as the wind surge moves
south across the Florida Keys coastal waters. Environmental
conditions will become more supportive of showers and
thunderstorms on Sunday and Monday.

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

63 NM South of Dry Tortugas Light...on Loggerhead Key.
42 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
33 NM South of Sand Key Light...off Key West.
23 NM South of Looe Key...off Big Pine Key.
16 NM Southeast of Sombrero Key Light...off Marathon.
22 NM Southeast of Alligator Reef Light...off Islamorada.
20 NM Southeast of Molasses Reef Light...off Key Largo.
18 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.

$$

GMZ031-172030-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
417 AM EDT Fri Oct 17 2025

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

.TODAY...Northeast to east winds near 15 knots, increasing to 15
to 20 knots. Bay waters a moderate chop, becoming choppy.
Isolated showers.
.TONIGHT AND SATURDAY...Northeast to east winds 15 to 20 knots.
Bay waters choppy.
.SATURDAY NIGHT...East winds near 15 knots. Bay waters a moderate
chop. Isolated showers.
.SUNDAY...East winds 10 to 15 knots. Bay waters a light to
moderate chop. Isolated showers and thunderstorms.
.SUNDAY NIGHT...East winds 10 to 15 knots. Bay waters a light to
moderate chop. Scattered showers and isolated thunderstorms.
.MONDAY...East winds 10 to 15 knots, increasing to near 15 knots.
Bay waters a light to moderate chop, becoming a moderate chop.
Isolated showers and thunderstorms.
.MONDAY NIGHT...Northeast to east winds near 15 knots. Bay waters
a moderate chop. Isolated showers and thunderstorms.
.TUESDAY AND TUESDAY NIGHT...Northeast to east winds 10 to 15
knots. Bay waters a light to moderate chop. Isolated showers.

$$

GMZ032-035-172030-
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 AM EDT Fri Oct 17 2025

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

.TODAY...Northeast to 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. Isolated showers.
.TONIGHT AND SATURDAY...Northeast to 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. Isolated showers.
.SATURDAY 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. Isolated showers.
.SUNDAY...East winds near 15 knots, decreasing to 10 to 15 knots.
Seas subsiding to 1 to 2 feet. Nearshore waters a moderate chop,
becoming a light to moderate chop. Scattered showers and isolated
thunderstorms.
.SUNDAY NIGHT...East winds 10 to 15 knots. Seas 1 to 2 foot.
Nearshore waters a light to moderate chop. Scattered showers and
isolated thunderstorms.
.MONDAY...East winds 10 to 15 knots, increasing to near 15 knots.
Seas 1 to 2 feet, building to 1 to 3 feet. Nearshore waters a
light to moderate chop, becoming a moderate chop. Isolated
showers and thunderstorms.
.MONDAY NIGHT...East winds near 15 knots. Seas 1 to 3 feet.
Nearshore waters a moderate chop. Isolated showers and
thunderstorms.
.TUESDAY AND TUESDAY NIGHT...Northeast to 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. Isolated
showers.

$$

GMZ042>044-172030-
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 Fri Oct 17 2025

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

.TODAY...Northeast to east winds 15 to 20 knots. Seas 2 to
4 feet, occasionally to 5 feet. Nearshore waters choppy.
Scattered showers.
.TONIGHT...Northeast to east winds 15 to 20 knots. Seas 2 to
4 feet, occasionally to 5 feet. Nearshore waters choppy. Isolated
showers.
.SATURDAY AND SATURDAY NIGHT...East winds 15 to 20 knots. Seas 2
to 4 feet, occasionally to 5 feet. Nearshore waters choppy.
Isolated showers.
.SUNDAY...East winds near 15 knots, decreasing to 10 to 15 knots.
Seas 2 to 3 feet. Nearshore waters a moderate chop, becoming a
light to moderate chop. Scattered showers and isolated
thunderstorms.
.SUNDAY NIGHT...East winds 10 to 15 knots. Seas 1 to 3 feet.
Nearshore waters a light to moderate chop. Scattered showers and
isolated thunderstorms.
.MONDAY...Northeast to east winds 10 to 15 knots, increasing to
near 15 knots. Seas building to 2 to 3 feet. Nearshore waters a
light to moderate chop, becoming a moderate chop. Scattered
showers and isolated thunderstorms.
.MONDAY NIGHT...East winds near 15 knots. Seas 2 to 3 feet.
Nearshore waters a moderate chop. Scattered showers and isolated
thunderstorms.
.TUESDAY AND TUESDAY NIGHT...Northeast to east winds 10 to 15
knots. Seas 1 to 3 feet. Nearshore waters a light to moderate
chop. Isolated showers.

$$

GMZ052>055-072>075-172030-
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 Fri Oct 17 2025

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

.TODAY...Northeast to east winds 15 to 20 knots. Seas 3 to
5 feet, occasionally to 6 feet. Wave Detail: Northeast to east
5 feet at 6 seconds. Scattered showers.
.TONIGHT...Northeast to east winds 15 to 20 knots. Seas 4 to
6 feet, occasionally to 8 feet. Wave Detail: Northeast to east
5 feet at 6 seconds. Scattered showers.
.SATURDAY...East winds 15 to 20 knots. Seas 4 to 6 feet,
occasionally to 8 feet. Wave Detail: Northeast to east 5 feet at
6 seconds. Scattered showers.
.SATURDAY NIGHT...East winds 15 to 20 knots. Seas 4 to 6 feet,
occasionally to 8 feet. Scattered showers.
.SUNDAY...East winds near 15 knots, decreasing to 10 to 15 knots.
Seas 3 to 4 feet, occasionally to 5 feet. Scattered showers and
isolated thunderstorms.
.SUNDAY NIGHT...East winds 10 to 15 knots. Seas 2 to 4 feet.
Scattered showers and isolated thunderstorms.
.MONDAY...Northeast to east winds near 15 knots, increasing to 15
to 20 knots. Seas 2 to 4 feet, occasionally to 5 feet. Scattered
showers and isolated thunderstorms.
.MONDAY NIGHT...Northeast to east winds 15 to 20 knots. Seas 3 to
5 feet, occasionally to 6 feet. Scattered showers and isolated
thunderstorms.
.TUESDAY...Northeast to east winds near 15 knots. Seas 3 to
4 feet, occasionally to 5 feet. Scattered showers.
.TUESDAY NIGHT...Northeast to east winds near 15 knots. Seas 3 to
4 feet, occasionally to 5 feet. Isolated showers.

$$

GMZ033-034-172030-
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 Fri Oct 17 2025

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

.TODAY...Northeast to east winds 15 to 20 knots. Seas 2 to
4 feet, occasionally to 5 feet. Wave Detail: Northeast to east 3
feet at 4 seconds. Isolated showers.
.TONIGHT AND SATURDAY...East winds 15 to 20 knots. Seas 3 to 5
feet, occasionally to 6 feet. Wave Detail: Northeast to east 4
feet at 5 seconds. Isolated showers.
.SATURDAY NIGHT...East winds 15 to 20 knots. Seas 3 to 5 feet,
occasionally to 6 feet. Isolated showers.
.SUNDAY...East winds near 15 knots, decreasing to 10 to 15 knots.
Seas subsiding to 2 to 3 feet. Scattered showers and isolated
thunderstorms.
.SUNDAY NIGHT...East winds 10 to 15 knots. Seas 2 to 3 feet.
Isolated showers and thunderstorms.
.MONDAY...Northeast to east winds 10 to 15 knots. Seas 2 to
3 feet. Isolated showers and thunderstorms.
.MONDAY NIGHT...Northeast to east winds near 15 knots. Seas 2 to
4 feet. Isolated showers and thunderstorms.
.TUESDAY AND TUESDAY NIGHT...Northeast to east winds 10 to 15
knots. Seas 2 to 3 feet. Isolated showers.

$$

AJP