599
FZUS52 KKEY 010827
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
427 AM EDT Mon Sep 1 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.

GMZ005-012030-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
427 AM EDT Mon Sep 1 2025

.SYNOPSIS...Somewhat unusual 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.

$$

GMZ031-012030-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
427 AM EDT Mon Sep 1 2025

.TODAY...Southwest to west winds 5 to 10 knots, increasing to near
10 knots. Bay waters smooth to a light chop, becoming a light chop.
Winds higher and bay waters rough in and around numerous showers
and scattered thunderstorms.
.TONIGHT...West winds near 10 knots, decreasing to 5 to 10 knots.
Bay waters a light chop, becoming smooth to a light chop.
Numerous showers and scattered thunderstorms.
.TUESDAY...West winds 5 to 10 knots, becoming southwest to west
near 10 knots. Bay waters smooth to a light chop, becoming a
light chop. Numerous showers and scattered thunderstorms.
.TUESDAY NIGHT...West winds 10 to 15 knots, decreasing to 5 to 10
knots. Bay waters a light to moderate chop, becoming smooth to a
light chop. Scattered showers and thunderstorms.
.WEDNESDAY...West winds 5 to 10 knots, increasing to 10 to
15 knots in the afternoon. Bay waters smooth to a light chop,
becoming a light to moderate 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 near 10 knots. Bay waters a
light chop. Numerous showers and scattered thunderstorms.
.THURSDAY NIGHT...Southwest to west 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.
.FRIDAY AND FRIDAY NIGHT...Southwest to west winds 5 to 10 knots.
Bay waters smooth to a light chop. Scattered showers and
thunderstorms.

$$

GMZ032-035-012030-
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-
427 AM EDT Mon Sep 1 2025

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

$$

GMZ042>044-012030-
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-
427 AM EDT Mon Sep 1 2025

.TODAY...Southwest to west winds near 10 knots, increasing to 10
to 15 knots. Seas 1 to 2 feet. Nearshore waters a light chop,
becoming a light to moderate chop late. Winds and seas higher in
and around numerous showers and scattered thunderstorms.
.TONIGHT...West winds 10 to 15 knots, becoming 5 to 10 knots
after midnight. Seas 1 to 3 feet, subsiding to 1 to 2 feet.
Nearshore waters a light to moderate chop, becoming smooth to a
light chop. Numerous showers and scattered thunderstorms.
.TUESDAY...West winds 5 to 10 knots, increasing to 10 to 15 knots.
Seas 1 to 2 feet, building to 1 to 3 feet. Nearshore waters
smooth to a light chop, becoming a light to moderate chop.
Numerous showers and scattered thunderstorms.
.TUESDAY NIGHT...West winds 10 to 15 knots, decreasing to 5 to 10
knots. Seas 1 to 3 feet, subsiding to 1 to 2 feet. Nearshore
waters a light to moderate chop, becoming smooth to a light chop.
Scattered showers and thunderstorms.
.WEDNESDAY...West winds increasing to 10 to 15 knots. Seas
building to 1 to 3 feet. Nearshore waters 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...West winds 10 to 15 knots. Seas 1 to 3 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.
.FRIDAY AND FRIDAY NIGHT...Southwest to west winds 5 to 10 knots.
Seas around 1 foot. Nearshore waters smooth to a light chop.
Scattered showers and thunderstorms.

$$

GMZ052>055-072>075-012030-
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-
427 AM EDT Mon Sep 1 2025

.TODAY...Southwest to west winds near 10 knots, increasing to 10
to 15 knots. Seas 1 to 3 feet, building to 2 to 3 feet. Wave
Detail: West 1 foot at 4 seconds. Winds and seas higher in and
around numerous showers and scattered thunderstorms.
.TONIGHT...West winds 10 to 15 knots, decreasing to 5 to 10 knots
after midnight. Seas 2 to 3 feet, subsiding to 1 to 2 feet. Wave
Detail: West 2 feet at 4 seconds. Numerous showers and scattered
thunderstorms.
.TUESDAY...Southwest to west winds 5 to 10 knots, increasing to
10 to 15 knots in the afternoon. Seas 1 to 2 feet, building to 2
to 3 feet. Wave Detail: West 1 foot at 4 seconds. Numerous
showers and scattered thunderstorms.
.TUESDAY NIGHT...West winds decreasing to near 10 knots. Seas
subsiding to 1 to 2 feet. Scattered showers and thunderstorms.
.WEDNESDAY...West winds increasing to 10 to 15 knots. Seas
building to 2 to 3 feet. Scattered showers and thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds decreasing to near 10
knots. Seas subsiding to 1 to 3 feet. Scattered showers and
thunderstorms.
.THURSDAY...Southwest to west winds 10 to 15 knots. Seas 2 to 3
feet. Scattered showers and thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 10 knots. Seas
1 to 3 feet. Scattered showers and thunderstorms.
.FRIDAY AND FRIDAY NIGHT...Southwest to west winds 5 to 10 knots.
Seas 1 to 2. Scattered showers and thunderstorms.

$$

GMZ033-034-012030-
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-
427 AM EDT Mon Sep 1 2025

.TODAY...Southwest to west winds 5 to 10 knots, increasing to
near 10 knots. Seas 1 to 2 feet. Wave Detail: West 2 feet at 4
seconds. Winds and seas higher in and around numerous showers and
scattered thunderstorms.
.TONIGHT...West to northwest winds 10 to 15 knots, becoming 5 to
10 knots after midnight. Seas around 2 feet, subsiding to 1 to 2
feet. Wave Detail: West to northwest 2 feet at 4 seconds.
Scattered showers and thunderstorms.
.TUESDAY...West winds 5 to 10 knots, increasing to near 10 knots.
Seas 1 to 2 feet. Wave Detail: West 1 foot at 4 seconds. Numerous
showers and scattered thunderstorms.
.TUESDAY NIGHT...West to northwest winds decreasing to 5 to 10
knots. Seas 1 to 2 feet. Scattered showers and thunderstorms.
.WEDNESDAY...West winds 5 to 10 knots, increasing to 10 to
15 knots in the afternoon. Seas 1 to 2 feet, building to around 2
feet. Numerous showers and scattered thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds decreasing to near 10
knots. Seas subsiding to 1 to 2 feet. Numerous showers and
scattered thunderstorms.
.THURSDAY...West winds 10 to 15 knots. Seas around 2 feet.
Numerous showers and scattered thunderstorms.
.THURSDAY NIGHT...West winds decreasing to 5 to 10 knots. Seas
subsiding to 1 to 2 feet. Scattered showers and thunderstorms.
.FRIDAY AND FRIDAY NIGHT...Southwest to west winds 5 to 10 knots.
Seas around 1 foot. Scattered showers and thunderstorms.

$$

JAM