357
FZUS52 KKEY 092023
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
423 PM EDT Sat Aug 9 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.

GMZ005-100830-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
423 PM EDT Sat Aug 9 2025

.SYNOPSIS...A tropical wave will continue slowly progressing
westward through the Keys tonight. This will promote light to
gentle east to southeast breezes (occasionally light to moderate
breezes) as well as above normal rain and thunder chances. As the
wave pushes further into the Gulf through the weekend, surface
high pressure across the Atlantic will slowly build into the Keys.
This will result in gentle to moderate east to southeast breezes
for early next week. Breezes slacken back to light to gentle
breezes towards the middle of next week.

The Approximate Shoreward Edge of the Gulf Stream as of August 8...

84 NM South of Dry Tortugas Light...on Loggerhead Key.
53 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
41 NM South of Sand Key Light...off Key West.
18 NM South of Looe Key...off Big Pine Key.
 9 NM Southeast of Sombrero Key Light...off Marathon.
 7 NM Southeast of Alligator Reef Light...off Islamorada.
 3 NM Southeast of Molasses Reef Light...off Key Largo.
 3 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.

$$

GMZ031-100830-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
423 PM EDT Sat Aug 9 2025

.TONIGHT...Southeast winds 5 to 10 knots, becoming southeast to
south and increasing to near 10 knots. Bay waters smooth to a
light chop, becoming a light chop. Winds and seas higher near
numerous showers and scattered thunderstorms.
.SUNDAY...Southeast to south winds 5 to 10 knots. Bay waters
smooth to a light chop. Numerous showers and scattered
thunderstorms.
.SUNDAY NIGHT...Southwest winds near 5 knots, becoming east to
southeast and increasing to near 10 knots. Bay waters smooth,
becoming a light chop. Scattered showers and isolated
thunderstorms.
.MONDAY...East to southeast winds 10 to 15 knots, decreasing to
near 10 knots. Bay waters a light to moderate chop, becoming a
light chop. Scattered showers and isolated thunderstorms.
.MONDAY NIGHT...East winds near 10 knots, becoming east to
southeast and increasing to 10 to 15 knots. Bay waters a light
chop, becoming a light to moderate chop. Scattered showers and
isolated thunderstorms.
.TUESDAY...East to southeast winds near 10 knots. Bay waters a
light chop. Scattered showers and isolated thunderstorms.
.TUESDAY NIGHT...East to southeast winds 5 to 10 knots. Bay
waters smooth to a light chop. Scattered showers and isolated
thunderstorms.
.WEDNESDAY...East to southeast winds 5 to 10 knots. Bay waters
smooth to a light chop. Scattered showers and isolated
thunderstorms.
.WEDNESDAY NIGHT...East winds 5 to 10 knots. Bay waters smooth to
a light chop. Scattered showers and isolated thunderstorms.
THURSDAY...East winds near 5 knots. Bay waters smooth. Scattered
showers and isolated thunderstorms.
.THURSDAY NIGHT...Northeast to east winds 5 to 10 knots. Bay
waters smooth to a light chop. Scattered showers and isolated
thunderstorms.

$$

GMZ032-035-100830-
Bayside and Gulf side from Craig Key to west end of Seven Mile
Bridge-
Gulf of Mexico from west end of Seven Mile Bridge to Halfmoon
Shoal out to 5 Fathoms-
423 PM EDT Sat Aug 9 2025

.TONIGHT...Southeast winds 5 to 10 knots, increasing to near 10
knots. Seas 1 foot or less, except around 1 foot west of the
Marquesas Keys. Nearshore waters smooth to a light chop, becoming
a light chop. Winds and seas higher near numerous showers and
scattered thunderstorms.
.SUNDAY...Southeast to south winds 5 to 10 knots, decreasing to
near 5 knots. Seas 1 foot or less. Nearshore waters smooth to a
light chop, becoming smooth. Numerous showers and scattered
thunderstorms.
.SUNDAY NIGHT...Variable winds near 5 knots, becoming east to
southeast and increasing to near 10 knots after midnight. Seas 1
foot or less, building to around 1 foot. Nearshore waters smooth,
becoming a light chop. Scattered showers and isolated
thunderstorms.
.MONDAY...East to southeast winds 10 to 15 knots. Seas around
1 foot, except building to 1 to 2 feet west of the Marquesas
Keys. Nearshore waters a light to moderate chop. Scattered showers
and isolated thunderstorms.
.MONDAY NIGHT...East to southeast winds 10 to 15 knots. Seas 1 to
2 feet, except around 2 feet west of the Marquesas Keys.
Nearshore waters a light to moderate chop. Scattered showers and
isolated thunderstorms.
.TUESDAY...East to southeast winds 10 to 15 knots, decreasing to
near 10 knots. Seas 1 to 2 feet, except around 2 feet west of the
Marquesas Keys. Nearshore waters a light to moderate chop,
becoming a light chop. Scattered showers and isolated
thunderstorms.
.TUESDAY NIGHT...East to southeast winds near 10 knots. Seas
1 to 2 feet. Nearshore waters a light chop. Scattered showers and
isolated thunderstorms.
.WEDNESDAY...East to southeast winds 5 to 10 knots. Seas around 1
foot. Nearshore waters smooth to a light chop. Scattered showers
and isolated thunderstorms.
.WEDNESDAY NIGHT...East winds 5 to 10 knots. Seas around 1 foot.
Nearshore waters smooth to a light chop. Scattered showers and
isolated thunderstorms.
.THURSDAY..East winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth. Scattered showers and isolated
thunderstorms.
.THURSDAY NIGHT...East winds 5 to 10 knots. Seas around 1 foot.
Nearshore waters smooth to a light chop. Scattered showers and
isolated thunderstorms.

$$

GMZ042>044-100830-
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-
423 PM EDT Sat Aug 9 2025

.TONIGHT...Southeast winds 5 to 10 knots, becoming southeast to
south and increasing to 10 to 15 knots after midnight. Seas 1 to
2 feet. Nearshore waters smooth to a light chop, becoming a light
to moderate chop. Winds and seas higher near numerous showers and
scattered thunderstorms.
.SUNDAY...Southeast to south 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. Numerous showers and scattered
thunderstorms.
.SUNDAY NIGHT...Variable winds near 5 knots, becoming east to
southeast and increasing to near 10 knots after midnight. Seas
around 1 foot, building to 1 to 2 feet. Nearshore waters smooth,
becoming a light chop. Scattered showers and isolated
thunderstorms.
.MONDAY...East to southeast winds 10 to 15 knots. Seas around 2 feet.
Nearshore waters a light to moderate chop. Scattered showers and
isolated thunderstorms.
.MONDAY NIGHT...East to southeast winds 10 to 15 knots. Seas
around 2 feet, except 2 to 3 feet west of Cosgrove Shoal Light.
Nearshore waters a light to moderate chop. Scattered showers and
isolated thunderstorms.
.TUESDAY...East to southeast winds 10 to 15 knots, decreasing to
near 10 knots. Seas around 2 feet, except 2 to 3 feet west of
Cosgrove Shoal Light. Nearshore waters a light to moderate chop,
becoming a light chop. Scattered showers and isolated
thunderstorms.
.TUESDAY NIGHT...East to southeast winds near 10 knots. Seas 1 to
2 feet, except subsiding to around 2 feet west of Cosgrove Shoal
Light. Nearshore waters a light chop. Scattered showers and
isolated thunderstorms.
.WEDNESDAY...East to southeast winds 5 to 10 knots. Seas 1 to 2
feet. Nearshore waters smooth to a light chop. Scattered showers
and isolated thunderstorms.
.WEDNESDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet.
Nearshore waters smooth to a light chop. Scattered showers and
isolated thunderstorms.
.THURSDAY...East winds near 5 knots. Seas 1 to 2 feet. Nearshore
waters smooth. Scattered showers and isolated thunderstorms.
.THURSDAY NIGHT...Northeast to east winds 5 to 10 knots. Seas 1
to 2 feet. Nearshore waters smooth to a light chop. Scattered
showers and isolated thunderstorms.

$$

GMZ052>055-072>075-100830-
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-
423 PM EDT Sat Aug 9 2025

.TONIGHT...Southeast winds 5 to 10 knots, becoming southeast to
south and increasing to near 10 knots. Seas 1 to 2 feet. Wave
Detail: East to southeast 2 feet at 4 seconds. Winds and seas
higher near numerous showers and scattered thunderstorms.
.SUNDAY...Southeast to south winds 5 to 10 knots, becoming east to
southeast and decreasing to near 5 knots. Seas 1 to 2 feet. Wave
Detail: Southeast 2 feet at 4 seconds. Numerous showers and
scattered thunderstorms.
.SUNDAY NIGHT...Variable winds near 5 knots, becoming east to
southeast and increasing to 10 to 15 knots after midnight. Seas 1
to 2 feet, building to 2 to 3 feet. Scattered showers and
isolated thunderstorms.
.MONDAY...East to southeast winds 10 to 15 knots. Seas 2 to 3
feet. Scattered showers and isolated thunderstorms.
.MONDAY NIGHT...East winds 10 to 15 knots. Seas 2 to 3 feet.
Scattered showers and isolated thunderstorms.
.TUESDAY...East to southeast winds 10 to 15 knots, decreasing to
near 10 knots. Seas 2 to 3 feet. Scattered showers and isolated
thunderstorms.
.TUESDAY NIGHT...East winds near 10 knots. Seas around 2 feet.
Scattered showers and isolated thunderstorms.
.WEDNESDAY THROUGH THURSDAY...East winds 5 to 10 knots. Seas 1 to
2 feet. Scattered showers and isolated thunderstorms.
.THURSDAY NIGHT...Northeast to east winds 5 to 10 knots. Seas
2 to 3 feet. Scattered showers and isolated thunderstorms.

$$

GMZ033-034-100830-
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-
423 PM EDT Sat Aug 9 2025

.TONIGHT...Southeast to south winds 5 to 10 knots, increasing 10
to 15 knots after midnight. Seas 1 to 2 feet, building to around
2 feet. Wave Detail: South 1 foot at 3 seconds. Winds and seas
higher near widespread showers and scattered thunderstorms.
.SUNDAY...South winds near 10 knots, becoming south to southwest
and decreasing to 5 to 10 knots. Seas 1 to 2 feet. Wave Detail:
South 1 foot at 3 seconds. Widespread showers and scattered
thunderstorms.
.SUNDAY NIGHT...South to southwest winds 5 to 10 knots, becoming
east to southeast after midnight. Seas around 1 foot. Scattered
showers and isolated thunderstorms.
.MONDAY...East to southeast winds near 10 knots. Seas 1 to 2 feet.
Scattered showers and isolated thunderstorms.
.MONDAY NIGHT...East to southeast winds near 10 knots, increasing
to near 15 knots. Seas 1 to 2 feet, building to 2 to 3 feet.
Scattered showers and isolated thunderstorms.
.TUESDAY...East to southeast winds 10 to 15 knots, decreasing to
near 10 knots. Seas 2 to 3 feet. Scattered showers and isolated
thunderstorms.
.TUESDAY NIGHT...East to southeast winds near 10 knots. Seas
around 2 feet. Scattered showers and isolated thunderstorms.
.WEDNESDAY...East to southeast winds 5 to 10 knots. Seas 1 to 2
feet. Scattered showers and isolated thunderstorms.
.WEDNESDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet.
Scattered showers and isolated thunderstorms.
.THURSDAY...East winds near 5 knots. Seas 1 to 2 feet. Scattered
showers and isolated thunderstorms.
.THURSDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet.
Scattered showers and isolated thunderstorms.

$$