465
FZUS52 KKEY 242021
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
421 PM EDT Sun Aug 24 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.

GMZ005-250830-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
421 PM EDT Sun Aug 24 2025

.SYNOPSIS...A weak subtropical ridge will remain over the Keys
through early to mid week. This will result in generally light
breezes, occasionally becoming light to gentle as well as variable
at times. Towards the latter half of the week, the ridge over the
Atlantic will strengthen slightly as a tropical wave moves
through the northwest Caribbean Sea. This will result in a
freshening winds with occasionally gentle to moderate breezes.
Also, increasing moisture is expected to lead to more widespread
showers and thunderstorms, especially late week.

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.

$$

GMZ031-250830-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
421 PM EDT Sun Aug 24 2025

.TONIGHT...Southwest to west winds 5 to 10 knots, becoming
variable near 5 knots. Bay waters smooth to a light chop, becoming
smooth. Isolated showers and thunderstorms.
.MONDAY...South to southwest winds near 5 knots. Bay waters
smooth. Scattered showers and isolated thunderstorms.
.MONDAY NIGHT...Variable winds near 5 knots, becoming northeast to
east after midnight. Bay waters smooth. Isolated showers and
thunderstorms.
.TUESDAY...Northeast to east winds near 5 knots, becoming east to
southeast. Bay waters smooth. Scattered showers and isolated
thunderstorms.
.TUESDAY NIGHT...East to southeast winds near 5 knots, becoming
east. Bay waters smooth. Scattered showers and isolated
thunderstorms.
.WEDNESDAY...East winds near 5 knots. Bay waters smooth.
Scattered showers and thunderstorms.
.WEDNESDAY NIGHT...East winds 5 to 10 knots. Bay
waters smooth to a light chop. Scattered showers and
thunderstorms.
.THURSDAY AND THURSDAY NIGHT...East winds 5 to 10 knots. Bay
waters smooth to a light chop. Scattered showers and
thunderstorms.
.FRIDAY...East to southeast winds near 5 knots. Bay waters
smooth. Numerous showers and scattered thunderstorms.
.FRIDAY NIGHT...East to southeast winds near 5 knots. Bay waters
smooth. Scattered showers and thunderstorms.

$$

GMZ032-035-250830-
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-
421 PM EDT Sun Aug 24 2025

.TONIGHT...Southwest to west winds 5 to 10 knots, becoming
variable near 5 knots. Seas 1 foot or less. Nearshore waters
smooth to a light chop, becoming smooth. Isolated showers and
thunderstorms.
.MONDAY...Variable winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth. Isolated showers and thunderstorms.
.MONDAY NIGHT...Variable winds near 5 knots, becoming northeast to
east after midnight. Seas 1 foot or less. Nearshore waters
smooth. Isolated showers and thunderstorms.
.TUESDAY...Northeast to east winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. Scattered showers and isolated
thunderstorms.
.TUESDAY NIGHT...Northeast to east winds near 5 knots. Seas
1 foot or less. Nearshore waters smooth. Scattered showers and
isolated thunderstorms.
.WEDNESDAY...Northeast to east winds 5 to 10 knots. Seas 1 foot
or less, except around 1 foot west of the Marquesas Keys.
Nearshore waters smooth to a light chop. Scattered showers and
thunderstorms.
.WEDNESDAY NIGHT...East winds 5 to 10 knots. Seas around
1 foot. Nearshore waters smooth to a light chop. Scattered showers
and thunderstorms.
.THURSDAY...East winds 5 to 10 knots. Seas around
1 foot. Nearshore waters smooth to a light chop. Scattered showers
and thunderstorms.
.THURSDAY NIGHT...East winds near 10 knots. Seas around 1 foot,
except building to 1 to 2 feet west of the Marquesas Keys.
Nearshore waters a light chop. Scattered showers and
thunderstorms.
.FRIDAY...East to southeast winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. Scattered showers and
thunderstorms.
.FRIDAY NIGHT...Northeast to east winds 5 to 10 knots, becoming
southeast after midnight. Seas 1 foot or less. Nearshore waters
smooth to a light chop. Numerous showers and scattered
thunderstorms.

$$

GMZ042>044-250830-
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-
421 PM EDT Sun Aug 24 2025

.TONIGHT...Southwest to west winds 5 to 10 knots, becoming
variable near 5 knots. Seas 1 foot or less. Nearshore waters
smooth to a light chop, becoming smooth. Isolated showers and
thunderstorms.
.MONDAY...Variable winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth. Isolated showers and thunderstorms.
.MONDAY NIGHT...Variable winds near 5 knots, becoming northeast to
east after midnight. Seas 1 foot or less. Nearshore waters
smooth. Isolated showers and thunderstorms.
.TUESDAY...Northeast to east winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. Scattered showers and isolated
thunderstorms.
.TUESDAY NIGHT...East winds 5 to 10 knots. Seas around 1 foot.
Nearshore waters smooth to a light chop. Scattered showers and
isolated thunderstorms.
.WEDNESDAY...East winds 5 to 10 knots. Seas around 1 foot.
Nearshore waters smooth to a light chop. Scattered showers and
thunderstorms.
.WEDNESDAY NIGHT...East winds near 10 knots. Seas 1 to 2 feet.
Nearshore waters a light chop. Scattered showers and
thunderstorms.
.THURSDAY...East winds 5 to 10 knots, increasing to near 10 knots.
Seas 1 to 2 feet. Nearshore waters smooth to a light chop,
becoming a light chop. Scattered showers and thunderstorms.
.THURSDAY NIGHT...East winds near 10 knots, decreasing to 5 to 10
knots. Seas 1 to 2 feet. Nearshore waters a light chop, becoming
smooth to a light chop. Scattered showers and thunderstorms.
.FRIDAY...East winds near 5 knots. Seas around 1 foot. Nearshore
waters smooth. Scattered showers and thunderstorms.
.FRIDAY NIGHT...East winds near 5 knots, becoming southeast after
midnight. Seas 1 foot or less. Nearshore waters smooth, becoming
smooth to a light chop. Scattered showers and thunderstorms.

$$

GMZ052>055-072>075-250830-
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-
421 PM EDT Sun Aug 24 2025

.TONIGHT...Variable winds 5 to 10 knots. Seas 1 to 2 feet. Wave
Detail: East 1 foot at 3 seconds. Scattered showers and isolated
thunderstorms.
.MONDAY...East to southeast winds 5 to 10 knots, becoming
northeast to east and decreasing to near 5 knots. Seas 1 to 2
feet. Wave Detail: East to southeast 1 foot at 4 seconds. Isolated
showers and thunderstorms.
.MONDAY NIGHT...Northeast to east winds 5 to 10 knots. Seas 1 to 2
feet. Wave Detail: East 1 foot at 4 seconds. Isolated showers and
thunderstorms.
.TUESDAY...Northeast to east winds 5 to 10 knots. Seas 1 to
2 feet. Isolated showers and thunderstorms.
.TUESDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet.
Scattered showers and isolated thunderstorms.
.WEDNESDAY...East winds 5 to 10 knots, becoming northeast to east
and increasing to near 10 knots. Seas 1 to 2 feet, building to
around 2 feet. Scattered showers and thunderstorms.
.WEDNESDAY NIGHT...Northeast to east winds 10 to 15 knots,
becoming east. Seas 2 to 3 feet. Scattered showers and
thunderstorms.
.THURSDAY...East winds near 10 knots. Seas around 2 feet.
Scattered showers and thunderstorms.
.THURSDAY NIGHT...Northeast to east winds near 10 knots, becoming
east to southeast. Seas around 2 feet. Scattered showers and
thunderstorms.
.FRIDAY...East winds near 5 knots. Seas 1 to 2 feet. Scattered
showers and thunderstorms.
.FRIDAY NIGHT...East winds 5 to 10 knots, becoming southeast to
south after midnight. Seas 1 to 2 feet. Scattered showers and
thunderstorms.

$$

GMZ033-034-250830-
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-
421 PM EDT Sun Aug 24 2025

.TONIGHT...Southwest to west winds 5 to 10 knots, becoming
variable near 5 knots. Seas around 1 foot. Wave Detail: West to
northwest 1 foot at 4 seconds. Scattered showers and isolated
thunderstorms.
.MONDAY...Variable winds near 5 knots, becoming west. Seas around
1 foot. Wave Detail: Northwest 1 foot at 4 seconds. Isolated
showers and thunderstorms.
.MONDAY NIGHT...Northwest to north winds near 5 knots, becoming
north to northeast. Seas around 1 foot. Wave Detail: Northwest 1
foot at 4 seconds. Isolated showers and thunderstorms.
.TUESDAY...North to northeast winds near 5 knots. Seas around
1 foot. Scattered showers and isolated thunderstorms.
.TUESDAY NIGHT...Northeast winds near 5 knots. Seas around
1 foot. Scattered showers and isolated thunderstorms.
.WEDNESDAY...Northeast to east winds 5 to 10 knots. Seas 1 to 2
feet. Scattered showers and thunderstorms.
.WEDNESDAY NIGHT...Northeast to east winds 5 to 10 knots. Seas 1 to 2
feet. Scattered showers and thunderstorms.
.THURSDAY...Northeast to east winds 5 to 10 knots. Seas 1 to 2
feet. Scattered showers and thunderstorms.
.THURSDAY NIGHT...East winds near 10 knots. Seas 1 to 2 feet.
Scattered showers and thunderstorms.
.FRIDAY...East winds near 5 knots. Seas around 1 foot. Numerous
showers and scattered thunderstorms.
.FRIDAY NIGHT...Northeast to east winds 5 to 10 knots, becoming
southeast after midnight. Seas 1 foot or less. Scattered showers
and thunderstorms.

$$