163
FZUS52 KKEY 302016
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
416 PM EDT Sat Aug 30 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.

GMZ005-310830-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
416 PM EDT Sat Aug 30 2025

.SYNOPSIS...An early season Canadian high pressure system will
continue to traverse the eastern United States and move into the
Atlantic over the next few days. This will allow for breezes to
remain light through the weekend. Pressure gradient across the
Gulf including Florida and the Florida Keys will increase early
next week, resulting in freshening breezes. Moisture will increase
as well, supporting higher shower and thunderstorm coverage
through early next 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.

$$

GMZ031-310830-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
416 PM EDT Sat Aug 30 2025

.TONIGHT...West to northwest winds 5 to 10 knots, becoming
southwest to west. Bay waters smooth to a light chop. Scattered
showers and thunderstorms.
.SUNDAY...West winds 5 to 10 knots, becoming west to northwest
near 10 knots. Bay waters smooth to a light chop, becoming a light
chop. Scattered showers and thunderstorms.
.SUNDAY NIGHT...Northwest winds near 10 knots. Bay waters
a light chop. Scattered showers and thunderstorms.
.MONDAY...Northwest winds near 10 knots, becoming west. Bay
waters a light chop. Scattered showers and thunderstorms.
.MONDAY NIGHT...West to northwest winds near 10 knots. Bay waters
a light chop. Scattered showers and thunderstorms.
.TUESDAY...West to northwest winds near 10 knots, becoming
southwest to west 10 to 15 knots. Bay waters a light chop,
becoming a light to moderate chop. Scattered showers and
thunderstorms.
.TUESDAY NIGHT...Southwest to west winds 10 to 15 knots. Bay
waters a light to moderate chop. Scattered showers and
thunderstorms.
.WEDNESDAY...Southwest to west winds increasing to near 15 knots.
Bay waters becoming a moderate chop. Scattered showers and
thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds near 15 knots. Bay
waters a moderate chop. Scattered showers and thunderstorms.
.THURSDAY...Southwest to west winds 15 to 20 knots. Bay waters
choppy. Scattered showers and thunderstorms.
.THURSDAY NIGHT...Southwest winds decreasing to 10 to 15 knots.
Bay waters becoming a light to moderate chop. Scattered showers
and thunderstorms.

$$

GMZ032-035-310830-
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-
416 PM EDT Sat Aug 30 2025

.TONIGHT...Northwest winds 5 to 10 knots, becoming southwest to
west near 5 knots after midnight. Seas 1 foot or less. Nearshore
waters smooth to a light chop, becoming smooth. Scattered showers
and thunderstorms.
.SUNDAY...West winds 5 to 10 knots, becoming west to northwest
near 10 knots. Seas building to around 1 foot. Nearshore waters
smooth to a light chop, becoming a light chop. Scattered showers
and thunderstorms.
.SUNDAY NIGHT...Northwest winds near 10 knots. Seas around
1 foot. Nearshore waters a light chop. Scattered showers and
thunderstorms.
.MONDAY...West to northwest winds near 10 knots. Seas around 1
foot. Nearshore waters a light chop. Scattered showers and
thunderstorms.
.MONDAY NIGHT...West to northwest winds near 10 knots. Seas
around 1 foot. Nearshore waters a light chop. Scattered showers
and thunderstorms.
.TUESDAY...West to northwest winds near 10 knots, becoming
southwest to west 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 thunderstorms.
.TUESDAY NIGHT...Southwest to west 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. Scattered showers and
thunderstorms.
.WEDNESDAY...Southwest to west winds near 15 knots. Seas 2 to 3
feet, except building to 3 to 4 feet west of the Marquesas Keys.
Nearshore waters a moderate chop. Scattered showers and
thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds 15 to 20 knots. Seas
2 to 3 feet, except 3 to 5 feet west of the Marquesas Keys.
Nearshore waters choppy. Scattered showers and thunderstorms.
.THURSDAY...Southwest to west winds near 20 knots, becoming near
15 knots in the afternoon. Seas 2 to 4 feet, occasionally to
5 feet. Nearshore waters rough, becoming a moderate chop.
Scattered showers and thunderstorms.
.THURSDAY NIGHT...West winds decreasing to 10 to 15 knots. Seas 1
to 2 feet. Nearshore waters becoming a light to moderate chop.
Scattered showers and thunderstorms.

$$

GMZ042>044-310830-
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-
416 PM EDT Sat Aug 30 2025

.TONIGHT...West to northwest winds 5 to 10 knots, becoming
southwest to west near 5 knots after midnight. Seas around 1 foot.
Nearshore waters smooth to a light chop, becoming smooth.
Scattered showers and thunderstorms.
.SUNDAY...West winds 5 to 10 knots, becoming west to northwest
near 10 knots. Seas around 1 foot. Nearshore waters smooth to a
light chop, becoming a light chop. Scattered showers and
thunderstorms.
.SUNDAY NIGHT...Northwest winds near 10 knots. Seas around 1
foot. Nearshore waters a light chop. Scattered showers and
thunderstorms.
.MONDAY...West to northwest winds near 10 knots. Seas around
1 foot. Nearshore waters a light chop. Scattered showers and
thunderstorms.
.MONDAY NIGHT...West to northwest winds near 10 knots. Seas
around 1 foot. Nearshore waters a light chop. Scattered showers
and thunderstorms.
.TUESDAY...West to northwest winds near 10 knots, becoming
southwest to west 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 thunderstorms.
.TUESDAY NIGHT...Southwest to west winds 10 to 15 knots. Seas 1
to 3 feet. Nearshore waters a light to moderate chop. Scattered
showers and thunderstorms.
.WEDNESDAY...Southwest to west winds near 15 knots. Seas 2 to
3 feet. Nearshore waters a moderate chop. Scattered showers and
thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds 15 to 20 knots. Seas
2 to 3 feet, except 3 to 4 feet west of Cosgrove Shoal Light.
Nearshore waters choppy. Scattered showers and thunderstorms.
.THURSDAY...Southwest to west winds 15 to 20 knots. Seas 2 to
4 feet, occasionally to 5 feet. Nearshore waters choppy.
Scattered showers and thunderstorms.
.THURSDAY NIGHT...West winds decreasing to 10 to 15 knots. Seas 1
to 2 feet. Nearshore waters a light to moderate chop. Scattered
showers and thunderstorms.

$$

GMZ052>055-072>075-310830-
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-
416 PM EDT Sat Aug 30 2025

..TONIGHT...West to northwest winds 5 to 10 knots, becoming
southwest after midnight. Seas around 1 foot. Wave Detail: East 1
foot at 3 seconds. Scattered showers and thunderstorms.
.SUNDAY...Southwest to west winds 5 to 10 knots, becoming west to
northwest near 10 knots. Seas around 1 foot. Wave Detail:
Southwest 1 foot at 2 seconds. Scattered showers and
thunderstorms.
.SUNDAY NIGHT...Northwest winds near 10 knots, decreasing to 5 to
10 knots. Seas around 1 foot. Scattered showers and
thunderstorms.
.MONDAY...West to northwest winds 5 to 10 knots, increasing to
near 10 knots. Seas around 1 foot. Scattered showers and
thunderstorms.
.MONDAY NIGHT...West to northwest winds near 10 knots. Seas
1 to 2 feet. Scattered showers and thunderstorms.
.TUESDAY...West to northwest winds near 10 knots, becoming
southwest to west 10 to 15 knots. Seas 1 to 2 feet, building to
around 2 feet. Scattered showers and thunderstorms.
.TUESDAY NIGHT...Southwest to west winds 10 to 15 knots. Seas
2 to 3 feet. Scattered showers and thunderstorms.
.WEDNESDAY...Southwest to west winds increasing to near 15 knots.
Seas 3 to 4 feet. Scattered showers and thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds near 15 knots. Seas 3
to 4 feet. Scattered showers and thunderstorms.
.THURSDAY...Southwest to west winds 15 to 20 knots, becoming west
near 15 knots. Seas 2 to 3 feet. Scattered showers and
thunderstorms.
.THURSDAY NIGHT...Southwest to west winds decreasing to 10 to 15
knots. Seas 1 to 2 feet. Scattered showers and thunderstorms.

$$

GMZ033-034-310830-
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-
416 PM EDT Sat Aug 30 2025

.TONIGHT...Northwest winds 5 to 10 knots, becoming southwest to
west after midnight. Seas around 1 foot. Wave Detail: Northwest 1
foot at 3 seconds. Scattered showers and thunderstorms.
.SUNDAY...Southwest to west winds 5 to 10 knots, becoming west to
northwest near 10 knots. Seas around 1 foot. Wave Detail:
Southwest to west 1 foot at 3 seconds. Scattered showers and
thunderstorms.
.SUNDAY NIGHT...Northwest winds near 10 knots. Seas 1 to 2 feet.
Scattered showers and thunderstorms.
.MONDAY...Northwest winds near 10 knots. Seas 1 to 2 feet.
Scattered showers and thunderstorms.
.MONDAY NIGHT...Northwest winds decreasing to 5 to 10 knots. Seas
subsiding to around 1 foot. Scattered showers and thunderstorms.
.TUESDAY...West to northwest winds 5 to 10 knots, becoming
southwest to west near 10 knots. Seas around 1 foot, building to 1
to 2 feet. Numerous showers and scattered thunderstorms.
.TUESDAY NIGHT...Southwest to west winds 10 to 15 knots. Seas 1
to 3 feet. Scattered showers and thunderstorms.
.WEDNESDAY...Southwest to west winds near 15 knots, increasing to
15 to 20 knots. Seas building to 2 to 4 feet, occasionally to 5
feet. Numerous showers and scattered thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds 15 to 20 knots. Seas
3 to 4 feet, occasionally to 5 feet. Numerous showers and
scattered thunderstorms.
.THURSDAY...Southwest to west winds near 20 knots, becoming west
15 to 20 knots. Seas 3 to 5 feet, occasionally to 6 feet.
Scattered showers and thunderstorms.
.THURSDAY NIGHT...West winds decreasing to 10 to 15 knots. Seas 2
to 3 feet. Scattered showers and thunderstorms.

$$