Coastal Waters Forecast
Issued by NWS Key West, FL

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699
FZUS52 KKEY 040817
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
417 AM EDT Sat Oct 4 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.

GMZ005-042030-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
417 AM EDT Sat Oct 4 2025

.SYNOPSIS...A weak area of low pressure located near the central
and northwestern Bahamas will act to weaken the pressure gradient
briefly across the Florida Keys this weekend. This will result in
slackening breezes veering from the northeast to the southeast
today through Sunday. This system is expected to drift west-
northwestward across the northwestern Bahamas and toward southern
Florida during the next couple of days. As it lifts north and
northwest of the Keys, high pressure across the Atlantic will
build back in resulting in freshening northeast to east breezes.

The Approximate Shoreward Edge of the Gulf Stream as of October
01...

42 NM South of Dry Tortugas Light...on Loggerhead Key.
33 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
33 NM South of Sand Key Light...off Key West.
35 NM South of Looe Key...off Big Pine Key.
16 NM Southeast of Sombrero Key Light...off Marathon.
10 NM Southeast of Alligator Reef Light...off Islamorada.
 6 NM Southeast of Molasses Reef Light...off Key Largo.
 5 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.

$$

GMZ031-042030-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
417 AM EDT Sat Oct 4 2025

.TODAY...Northeast to east winds 10 to 15 knots. Bay waters a
light to moderate chop. Winds higher and bay waters rough in and
around numerous showers and isolated thunderstorms.
.TONIGHT...Northeast to east winds 10 to 15 knots, becoming east
to southeast 5 to 10 knots. Bay waters a light to moderate chop,
becoming smooth to a light chop. Winds higher and bay waters rough
in and around scattered showers and isolated thunderstorms.
.SUNDAY...Southeast winds 5 to 10 knots. Bay waters smooth to a
light chop. Winds higher and bay waters rough in and around
scattered showers and isolated thunderstorms.
.SUNDAY NIGHT...East to southeast winds 5 to 10 knots. Bay waters
smooth to a light chop. Scattered showers and isolated
thunderstorms.
.MONDAY...Northeast to east winds near 10 knots, increasing to 10
to 15 knots. Bay waters a light chop, becoming a light to
moderate chop. Scattered showers and isolated thunderstorms.
.MONDAY NIGHT...Northeast to east winds 10 to 15 knots. Bay
waters a light to moderate chop. Scattered showers and isolated
thunderstorms.
.TUESDAY...Northeast to east winds 10 to 15 knots, increasing to
15 to 20 knots. Bay waters a light to moderate chop, becoming
choppy. Scattered showers and isolated thunderstorms.
.TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...Northeast to east winds
15 to 20 knots. Bay waters choppy. Scattered showers and isolated
thunderstorms.

$$

GMZ032-035-042030-
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 Sat Oct 4 2025

.TODAY...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. Winds and seas higher in and
around numerous showers and isolated thunderstorms.
.TONIGHT...Northeast to east winds 10 to 15 knots, becoming east
near 10 knots. Seas 1 to 2 feet. Nearshore waters a light to
moderate chop, becoming a light chop. Winds and seas higher in and
around scattered showers and isolated thunderstorms.
.SUNDAY...Southeast winds 5 to 10 knots, briefly decreasing to
near 5 knots in the afternoon. Seas subsiding to 1 foot or less.
West of the Marquesas Keys, seas 1 to 2 feet, subsiding to around
1 foot. Nearshore waters smooth to a light chop, becoming smooth.
Winds and seas higher in and around scattered showers and
isolated thunderstorms.
.SUNDAY NIGHT...East to southeast 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. Scattered showers and
isolated thunderstorms.
.MONDAY...Northeast to east winds near 10 knots, increasing to 10
to 15 knots. Seas around 1 foot, building to 1 to 2 feet.
Nearshore waters a light chop, becoming a light to moderate chop.
Scattered showers and isolated thunderstorms.
.MONDAY NIGHT...Northeast to east winds 10 to 15 knots. Seas
1 to 2 feet. Nearshore waters a light to moderate chop. Scattered
showers and isolated thunderstorms.
.TUESDAY...Northeast to east winds 10 to 15 knots, increasing to
15 to 20 knots. Seas 1 to 2 feet, building to 2 to 3 feet.
Nearshore waters a light to moderate chop, becoming choppy.
Scattered showers and isolated thunderstorms.
.TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...Northeast to east winds
15 to 20 knots. Seas 2 to 3 feet, except 3 to 4 feet west of the
Marquesas Keys. Nearshore waters choppy. Scattered showers and
isolated thunderstorms.

$$

GMZ042>044-042030-
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 Oct 4 2025

.TODAY...Northeast to east winds 10 to 15 knots. Seas 2 to
3 feet. Nearshore waters a light to moderate chop. Winds and seas
higher in and around numerous showers and isolated thunderstorms.
.TONIGHT...Northeast to east winds 10 to 15 knots, becoming east
to southeast 5 to 10 knots. Seas 2 to 3 feet, subsiding to 1 to 2
feet. Nearshore waters a light to moderate chop, becoming smooth
to a light chop. Winds and seas higher in and around scattered
showers and isolated thunderstorms.
.SUNDAY...Southeast winds 5 to 10 knots, briefly decreasing to
near 5 knots in the afternoon. Seas 1 to 2 feet. Nearshore waters
smooth to a light chop, becoming smooth. Winds and seas higher in
and around scattered showers and isolated thunderstorms.
.SUNDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
around 1 foot. Nearshore waters smooth to a light chop. Scattered
showers and isolated thunderstorms.
.MONDAY...Northeast to east winds 5 to 10 knots, increasing to 10
to 15 knots. Seas building to 1 to 2 feet. Nearshore waters
smooth to a light chop, becoming a light to moderate chop.
Scattered showers and isolated thunderstorms.
.MONDAY NIGHT...Northeast to east winds 10 to 15 knots. Seas 1 to
2 feet. Nearshore waters a light to moderate chop. Scattered
showers and isolated thunderstorms.
.TUESDAY...Northeast to east winds 10 to 15 knots, increasing to
15 to 20 knots in the afternoon. Seas building to 2 to 3 feet.
Nearshore waters a light to moderate chop, becoming choppy.
Scattered showers and isolated thunderstorms.
.TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...Northeast to east winds
15 to 20 knots. Seas 2 to 4 feet. Nearshore waters choppy.
Scattered showers and isolated thunderstorms.

$$

GMZ052>055-072>075-042030-
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 Oct 4 2025

.TODAY...Northeast to east winds 10 to 15 knots. Seas 3 to 5
feet, occasionally to 6 feet, subsiding to 2 to 4 feet,
occasionally to 5 feet. Wave Detail: Northeast to east 4 feet at
6 seconds. Winds and seas higher in and around scattered showers
and isolated thunderstorms.
.TONIGHT...Northeast to east winds 10 to 15 knots, becoming
southeast to south near 10 knots. Seas subsiding to 2 to 3 feet.
Wave Detail: Northeast to east 3 feet at 6 seconds. Winds and
seas higher in and around scattered showers and isolated
thunderstorms.
.SUNDAY...South to southwest winds 5 to 10 knots, becoming east to
southeast and briefly decreasing to near 5 knots in the
afternoon. Seas 2 to 3 feet, subsiding to 1 to 2 feet. Wave
Detail: Northeast to east 2 feet at 6 seconds. Winds and seas
higher in and around scattered showers and isolated thunderstorms.
.SUNDAY NIGHT...East to southeast winds increasing to near 10
knots. Seas 1 to 2 feet. Scattered showers and isolated
thunderstorms.
.MONDAY...Northeast to east winds near 10 knots, increasing to 10
to 15 knots. Seas building to 2 to 3 feet. Scattered showers and
isolated thunderstorms.
.MONDAY NIGHT...Northeast to east winds 10 to 15 knots. Seas 2 to
3 feet. Scattered showers and isolated thunderstorms.
.TUESDAY...Northeast to east winds 10 to 15 knots, increasing to
15 to 20 knots. Seas building to 2 to 4 feet, occasionally to 5
feet. Scattered showers and isolated thunderstorms.
.TUESDAY NIGHT...Northeast to east winds 15 to 20 knots. Seas 2
to 4 feet, occasionally to 5 feet. Scattered showers and isolated
thunderstorms.
.WEDNESDAY...Northeast to east winds 15 to 20 knots. Seas 3 to
5 feet, occasionally to 6 feet. Scattered showers and isolated
thunderstorms.
.WEDNESDAY NIGHT...Northeast to east winds decreasing to near 15
knots. Seas 3 to 4 feet, occasionally to 5 feet. Scattered showers
and isolated thunderstorms.

$$

GMZ033-034-042030-
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 Oct 4 2025

.TODAY...Northeast to east winds near 15 knots, decreasing to 10
to 15 knots. Seas 3 to 4 feet, occasionally to 5 feet, subsiding
to 2 to 3 feet. Wave Detail: Northeast to east 4 feet at 5
seconds. Numerous showers and isolated thunderstorms.
.TONIGHT...Northeast to east winds 10 to 15 knots, becoming east
to southeast. Seas 2 to 3 feet. Wave Detail: East 2 feet at 4
seconds. Scattered showers and isolated thunderstorms.
.SUNDAY...East to southeast winds near 10 knots, decreasing to 5
to 10 knots. Seas subsiding to 1 to 2 feet. Wave Detail: East 2
feet at 4 seconds. Scattered showers and isolated thunderstorms.
.SUNDAY NIGHT...East winds 5 to 10 knots. Seas around 1 foot.
Scattered showers and isolated thunderstorms.
.MONDAY...Northeast to east winds 5 to 10 knots, increasing to
near 10 knots. Seas around 1 foot. Scattered showers and isolated
thunderstorms.
.MONDAY NIGHT...Northeast to east winds 10 to 15 knots. Seas
around 1 foot, building to around 2 feet. Scattered showers and
isolated thunderstorms.
.TUESDAY...Northeast to east winds increasing to near 15 knots.
Seas 2 to 3 feet. Scattered showers and isolated thunderstorms.
.TUESDAY NIGHT...Northeast to east winds 15 to 20 knots. Seas
2 to 4 feet, occasionally to 5 feet. Scattered showers and
isolated thunderstorms.
.WEDNESDAY AND WEDNESDAY NIGHT...Northeast to east winds 15 to 20
knots. Seas 3 to 4 feet, occasionally to 5 feet. Scattered
showers and isolated thunderstorms.

$$