Coastal Waters Forecast
Issued by NWS Key West, FL

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FZUS52 KKEY 311425
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
1025 AM EDT Sun Aug 31 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.

GMZ005-010230-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
1025 AM EDT Sun Aug 31 2025

.SYNOPSIS...Somewhat unusual gentle westerly breezes prevail
across the Florida Keys as our area is situated between ridging in
the Caribbean and troughing along the Eastern Seaboard. This
pattern will remain relatively unchanged throughout the forecast
as the trough lazes over the east coast of CONUS while a surface
low develops along the Georgia coastline. This low is progged to
meander off into the western North Atlantic and rest on the west
edge of the Bermuda High promoting an extension of the already
established pattern in the Keys.

The Approximate Shoreward Edge of the Gulf Stream as of August 21...

20 NM South of Dry Tortugas Light...on Loggerhead Key.
 9 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
 9 NM South of Sand Key Light...off Key West.
13 NM South of Looe Key...off Big Pine Key.
17 NM Southeast of Sombrero Key Light...off Marathon.
17 NM Southeast of Alligator Reef Light...off Islamorada.
13 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.

$$

GMZ031-010230-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
1025 AM EDT Sun Aug 31 2025

.THIS AFTERNOON...Southwest to west winds near 10 knots, becoming
west. Bay waters a light chop. Winds higher and bay waters rough
in and around scattered showers and thunderstorms.
.TONIGHT...West to northwest winds near 10 knots, decreasing to 5
to 10 knots. Bay waters a light chop, becoming smooth to a light
chop. Scattered showers and thunderstorms.
.MONDAY...West winds 5 to 10 knots, increasing to near 10 knots.
Bay waters smooth to a light chop, becoming a light chop.
Scattered showers and thunderstorms.
.MONDAY NIGHT...Northwest winds decreasing to 5 to 10 knots. Bay
waters becoming smooth to a light chop. Scattered showers and
thunderstorms.
.TUESDAY...West to northwest winds 5 to 10 knots, becoming
southwest to west. Bay waters smooth to a light chop. Scattered
showers and thunderstorms.
.TUESDAY NIGHT...West winds 5 to 10 knots. Bay waters smooth to a
light chop. Scattered showers and thunderstorms.
.WEDNESDAY...Southwest to west winds increasing to near 10 knots.
Bay waters becoming a light chop. Scattered showers and
thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds near 10 knots. Bay
waters a light chop. Scattered showers and thunderstorms.
.THURSDAY...Southwest to west winds 10 to 15 knots. Bay waters a
light to moderate chop. Numerous showers and scattered
thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 10 knots. Bay
waters a light chop. Scattered showers and thunderstorms.

$$

GMZ032-035-010230-
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-
1025 AM EDT Sun Aug 31 2025

.THIS AFTERNOON...Southwest to west winds near 10 knots, becoming
west. Seas around 1 foot. Nearshore waters a light chop. Winds
and seas higher in and around scattered showers and thunderstorms.
.TONIGHT...West to northwest winds near 10 knots, decreasing to 5
to 10 knots. Seas around 1 foot. Nearshore waters a light chop,
becoming smooth to a light chop. Scattered showers and
thunderstorms.
.MONDAY...West 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 thunderstorms.
.MONDAY NIGHT...Northwest winds decreasing to 5 to 10 knots. Seas
subsiding to 1 foot or less. Nearshore waters becoming smooth to
a light chop. Scattered showers and thunderstorms.
.TUESDAY...West winds 5 to 10 knots. Seas 1 foot or less.
Nearshore waters smooth to a light chop. Scattered showers and
thunderstorms.
.TUESDAY NIGHT...West winds 5 to 10 knots. Seas 1 foot or less.
Nearshore waters smooth to a light chop. Scattered showers and
thunderstorms.
.WEDNESDAY...Southwest to west winds near 10 knots, increasing to
10 to 15 knots. Seas building to 1 to 2 feet. Nearshore waters a
light chop, becoming a light to moderate chop. Scattered showers
and thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds near 10 knots. Seas
1 to 2 feet. Nearshore waters a light chop. Scattered showers and
thunderstorms.
.THURSDAY...Southwest to west winds 10 to 15 knots. Seas 1 to
2 feet. Nearshore waters a light to moderate chop. Numerous
showers and scattered thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 10 knots. Seas
1 to 2 feet. Nearshore waters a light chop. Scattered showers and
thunderstorms.

$$

GMZ042>044-010230-
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-
1025 AM EDT Sun Aug 31 2025

.THIS AFTERNOON...Southwest to west winds near 10 knots, becoming
west. Seas around 1 foot. Nearshore waters a light chop. Winds
and seas higher in and around scattered showers and thunderstorms.
.TONIGHT...West to northwest winds near 10 knots, decreasing to 5
to 10 knots. Seas around 1 foot. Nearshore waters a light chop,
becoming smooth to a light chop. Scattered showers and
thunderstorms.
.MONDAY...West 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 thunderstorms.
.MONDAY NIGHT...West to northwest winds decreasing to 5 to 10
knots. Seas subsiding to 1 foot or less. Nearshore waters
becoming smooth to a light chop. Scattered showers and
thunderstorms.
.TUESDAY...West to northwest winds 5 to 10 knots, becoming
southwest to west in the afternoon. Seas around 1 foot. Nearshore
waters smooth to a light chop. Scattered showers and
thunderstorms.
.TUESDAY NIGHT...West winds 5 to 10 knots. Seas around 1 foot.
Nearshore waters smooth to a light chop. Scattered showers and
thunderstorms.
.WEDNESDAY...Southwest to west winds near 10 knots, increasing to
10 to 15 knots. Seas building to 1 to 2 feet. Nearshore waters a
light chop, becoming a light to moderate chop. Scattered showers
and thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds near 10 knots. Seas
1 to 2 feet. Nearshore waters a light chop. Scattered showers and
thunderstorms.
.THURSDAY...Southwest to west winds 10 to 15 knots. Seas 1 to
2 feet. Nearshore waters a light to moderate chop. Scattered
showers and thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 10 knots. Seas
1 to 2 feet. Nearshore waters a light chop. Scattered showers and
thunderstorms.

$$

GMZ052>055-072>075-010230-
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-
1025 AM EDT Sun Aug 31 2025

.THIS AFTERNOON...Southwest to west winds near 10 knots, becoming
west to northwest late. Seas 1 to 2 feet. Wave Detail: West 1
foot at 2 seconds. Winds and seas higher in and around scattered
showers and thunderstorms.
.TONIGHT...West to northwest winds near 10 knots, decreasing to 5
to 10 knots. Seas 1 to 2 feet. Wave Detail: Northwest 1 foot at 3
seconds. Scattered showers and thunderstorms.
.MONDAY...West winds 5 to 10 knots, increasing to near 10 knots.
Seas 1 to 2 feet. Wave Detail: Northwest 1 foot at 3 seconds.
Scattered showers and thunderstorms.
.MONDAY NIGHT...West to northwest winds near 10 knots, decreasing
to 5 to 10 knots. Seas 1 to 2 feet. Scattered showers and
thunderstorms.
.TUESDAY...West winds 5 to 10 knots. Seas around 1 to 2 feet.
Scattered showers and thunderstorms.
.TUESDAY NIGHT...West winds 5 to 10 knots. Seas 1 to 2 feet.
Scattered showers and thunderstorms.
.WEDNESDAY...Southwest to west winds near 10 knots, increasing to
10 to 15 knots. Seas 1 to 3 feet. Scattered showers and
thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds near 10 knots. Seas
1 to 2 feet. Scattered showers and thunderstorms.
.THURSDAY...Southwest to west winds 10 to 15 knots. Seas 1 to 3
feet. Scattered showers and thunderstorms.
.THURSDAY NIGHT...Southwest to west winds decreasing to 5 to 10
knots. Seas subsiding to 1 to 2 feet. Scattered showers and
thunderstorms.

$$

GMZ033-034-010230-
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-
1025 AM EDT Sun Aug 31 2025

.THIS AFTERNOON...Southwest to west winds near 10 knots, becoming
west. Seas 1 to 2 feet. Wave Detail: West 1 foot at 2 seconds.
Winds and seas higher in and around scattered showers and thunderstorms.
.TONIGHT...West to northwest winds near 10 knots, decreasing to 5
to 10 knots. Seas around 1 foot. Wave Detail: Northwest 1 foot at
3 seconds. Scattered showers and thunderstorms.
.MONDAY...West to northwest winds 5 to 10 knots. Seas around
1 foot. Wave Detail: Northwest 1 foot at 3 seconds. Scattered
showers and thunderstorms.
.MONDAY NIGHT...Northwest winds 5 to 10 knots. Seas around
1 foot. Scattered showers and thunderstorms.
.TUESDAY...West to northwest winds 5 to 10 knots. Seas around 1
foot. Scattered showers and thunderstorms.
.TUESDAY NIGHT...West winds 5 to 10 knots. Seas building to 1 to
2 feet. Scattered showers and thunderstorms.
.WEDNESDAY...West winds near 10 knots, increasing to 10 to 15
knots. Seas 1 to 2 feet, building to around 2 feet. Numerous
showers and scattered thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds near 10 knots. Seas
around 2 feet. Numerous showers and scattered thunderstorms.
.THURSDAY...Southwest to west winds 10 to 15 knots. Seas around
2 feet. Numerous showers and scattered thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 10 knots. Seas
1 to 2 feet. Scattered showers and thunderstorms.

$$