606
FZUS52 KKEY 200755
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
355 AM EDT Thu Aug 20 2026

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.

The Wave Detail section highlights the period and direction of
origin for the highest-energy waves, as well as any long-period
swells moving in a different direction than the wind.

GMZ005-202000-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
355 AM EDT Thu Aug 20 2026

.SYNOPSIS...
A split ridge across our waters with a nearby col will result in
light and variable winds today. The split ridge pattern will
remain in place through the end of the week and early in the
weekend with a mostly light to gentle variable wind pattern. Winds
then increase and become more southeasterly late weekend and into
the new week with daily gentle to moderate breezes expected. In
addition, atmospheric moisture is starting to recover across the
area after the Saharan dust that blanketed the area continues to
depart, so scattered showers and occasional thunderstorms could
occur with rain chances peaking around 30 percent over the next
several days. However, rain chances will increase further by the
new week as the southeasterly flow becomes more established.

The Approximate Shoreward Edge of the Gulf Stream as of August
13, 2026...

38 NM South of Dry Tortugas Light...on Loggerhead Key.
20 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
17 NM South of Sand Key Light...off Key West.
21 NM South of Looe Key...off Big Pine Key.
18 NM Southeast of Sombrero Key Light...off Marathon.
 7 NM Southeast of Alligator Reef Light...off Islamorada.
 7 NM Southeast of Molasses Reef Light...off Key Largo.
 2 NM Southeast of Carysfort Reef Light...off Ocean Reef.

Gulf Stream Information Courtesy of the National Weather Service in
Key West, using data from RTOFS and NASA SPoRT SST.

$$

GMZ031-202000-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
355 AM EDT Thu Aug 20 2026

.TODAY...Southwest winds near 5 knots, becoming south to
southwest. Bay waters smooth. A chance of showers with a slight
chance of thunderstorms.
.TONIGHT...South winds 5 to 10 knots. Bay waters smooth to a
light chop.
.FRIDAY...South winds near 5 knots. Bay waters smooth.
.FRIDAY NIGHT...Southeast to south winds near 5 knots. Bay waters
smooth.
.SATURDAY...Southeast to south winds near 5 knots. Bay waters
smooth. A slight chance of showers and thunderstorms.
.SATURDAY NIGHT...Southeast winds 5 to 10 knots. Bay waters
smooth to a light chop.
.SUNDAY...Southeast winds near 5 knots. Bay waters smooth. A
slight chance of showers and thunderstorms.
.SUNDAY NIGHT...Southeast winds near 5 knots. Bay waters smooth.
A slight chance of showers and thunderstorms.
.MONDAY...East to southeast winds 5 to 10 knots. Bay waters
smooth to a light chop. A slight chance of showers and
thunderstorms.
.MONDAY NIGHT...East winds 5 to 10 knots. Bay waters smooth to a
light chop. A chance of showers and thunderstorms.

$$

GMZ032-035-202000-
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-
355 AM EDT Thu Aug 20 2026

.TODAY...West winds near 5 knots. Seas 1 foot or less. Nearshore
waters smooth. A slight chance of showers and thunderstorms.
.TONIGHT...Southwest to west winds near 5 knots, becoming
southeast to south. Seas 1 foot or less. Nearshore waters smooth.
A slight chance of showers and thunderstorms.
.FRIDAY...Southeast to south winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth.
.FRIDAY NIGHT...Southeast winds near 5 knots, increasing to 5 to
10 knots. Seas 1 foot or less. Nearshore waters smooth, becoming
smooth to a light chop.
.SATURDAY...Southeast winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth.
.SATURDAY NIGHT...East to southeast winds near 5 knots, becoming
southeast. Seas 1 foot or less. Nearshore waters smooth.
.SUNDAY...East to southeast winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. A slight chance of showers and
thunderstorms.
.SUNDAY NIGHT...East to southeast winds near 5 knots. Seas 1 foot
or less. Nearshore waters smooth. A slight chance of showers and
thunderstorms.
.MONDAY...East to southeast winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. A slight chance of showers and
thunderstorms.
.MONDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
1 foot or less. Nearshore waters smooth to a light chop. A chance
of showers and thunderstorms.

$$

GMZ042>044-202000-
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-
355 AM EDT Thu Aug 20 2026

.TODAY...Southwest to west winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. A slight chance of showers and
thunderstorms.
.TONIGHT...Southwest to west winds near 5 knots, becoming
southeast to south. Seas 1 foot or less. Nearshore waters smooth.
.FRIDAY...Southeast to south winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth.
.FRIDAY NIGHT...East to southeast winds 5 to 10 knots. Seas around
1 foot. Nearshore waters smooth to a light chop.
.SATURDAY...East to southeast winds near 5 knots. Seas around
1 foot. Nearshore waters smooth.
.SATURDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
around 1 foot. Nearshore waters smooth to a light chop.
.SUNDAY...East to southeast winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. A slight chance of showers and
thunderstorms.
.SUNDAY NIGHT...East to southeast winds near 5 knots. Seas 1
foot less. Nearshore waters smooth. A slight chance of showers
and thunderstorms.
.MONDAY...East to southeast winds 5 to 10 knots. Seas around
1 foot. Nearshore waters smooth to a light chop. A slight chance
of showers.
.MONDAY NIGHT...East winds near 10 knots. Seas 1 to 2 feet.
Nearshore waters a light chop. A chance of showers and
thunderstorms.

$$

GMZ052>055-072>075-202000-
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-
355 AM EDT Thu Aug 20 2026

.TODAY...South to southwest winds near 5 knots, becoming
northeast to east. Seas around 1 foot.
.TONIGHT...Northeast to east winds 5 to 10 knots, becoming
southeast. Seas 1 to 2 feet.
.FRIDAY...East to southeast winds near 5 knots. Seas around
1 foot. Wave Detail: East to southeast 1 foot at 3 seconds.
.FRIDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet.
.SATURDAY...East winds near 5 knots. Seas around 1 foot.
.SATURDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet.
.SUNDAY...East winds 5 to 10 knots. Seas 1 to 2 feet.
.SUNDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet. A
slight chance of showers and thunderstorms.
.MONDAY...East winds 5 to 10 knots. Seas 1 to 2 feet. A slight
chance of showers.
.MONDAY NIGHT...East winds near 10 knots. Seas 1 to 3 feet. A
chance of showers and thunderstorms.

$$

GMZ033-034-202000-
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-
355 AM EDT Thu Aug 20 2026

.TODAY...Northwest winds near 5 knots. Seas around 1 foot. Wave
Detail: Northwest 1 foot at 5 seconds. A slight chance of showers
and thunderstorms.
.TONIGHT...North winds near 5 knots, becoming southeast to south.
Seas around 1 foot. Wave Detail: Northwest 1 foot at 5 seconds. A
slight chance of showers and thunderstorms.
.FRIDAY...South to southwest winds near 5 knots, becoming west.
Seas around 1 foot. Wave Detail: Northwest 1 foot at 4 seconds.
.FRIDAY NIGHT...North to northeast winds near 5 knots, becoming
southeast. Seas around 1 foot. A slight chance of showers and
thunderstorms.
.SATURDAY...Southeast to south winds near 5 knots, becoming
northwest. Seas around 1 foot.
.SATURDAY NIGHT...North to northeast winds near 5 knots, becoming
east to southeast. Seas 1 foot or less.
.SUNDAY...Northeast winds near 5 knots. Seas 1 foot or less.
.SUNDAY NIGHT...East winds near 5 knots. Seas 1 foot or less. A
slight chance of showers and thunderstorms.
.MONDAY...East to southeast winds near 5 knots. Seas around
1 foot. A slight chance of showers and thunderstorms.
.MONDAY NIGHT...East winds 5 to 10 knots. Seas around 1 foot. A
chance of showers and thunderstorms.

$$