Coastal Waters Forecast
Issued by NWS Key West, FL

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FZUS52 KKEY 162029
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
429 PM EDT Sun Aug 16 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.

GMZ005-170830-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
429 PM EDT Sun Aug 16 2026

.SYNOPSIS...Generally gentle east to southeast breezes will become
light and variable at times across the local waters over the next
few days as ridging remains the dominant weather feature across
the area. Northward movement of the subtropical ridge away from
the Keys will allow a col region to set up between Florida and
Cuba. Shower coverage will be kept far below normal because of a
Saharan Air Layer moving over the Keys waters.

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.

$$

GMZ031-170830-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
429 PM EDT Sun Aug 16 2026

.TONIGHT...East winds near 10 knots early, decreasing to 5 to 10
knots. Bay waters a light chop, becoming smooth to a light chop.
.MONDAY...Southeast to south winds near 5 knots, becoming
southwest. Bay waters smooth.
.MONDAY NIGHT...Southwest to west winds near 5 knots. Bay waters
smooth.
.TUESDAY...West winds near 5 knots, becoming west to northwest and
increasing to 5 to 10 knots. Bay waters smooth, becoming smooth
to a light chop.
.TUESDAY NIGHT...West to northwest winds 5 to 10 knots. Bay
waters smooth to a light chop.
.WEDNESDAY...West winds 5 to 10 knots. Bay waters smooth to a
light chop. A slight chance of showers and thunderstorms.
.WEDNESDAY NIGHT...West winds 5 to 10 knots. Bay waters smooth to
a light chop. A slight chance of showers.
.THURSDAY...South to southwest winds near 5 knots, increasing to
5 to 10 knots. Bay waters smooth, becoming smooth to a light chop.
A slight chance of showers and thunderstorms.
.THURSDAY NIGHT...South winds near 5 knots. Bay waters smooth. A
slight chance of showers.
.FRIDAY...Southeast to south winds near 5 knots. Bay waters
smooth. A slight chance of showers and thunderstorms.
.FRIDAY NIGHT...Southeast winds near 5 knots. Bay waters smooth.
A slight chance of showers.

$$

GMZ032-035-170830-
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-
429 PM EDT Sun Aug 16 2026

.TONIGHT...East winds near 10 knots early, decreasing to 5 to 10
knots. Seas around 1 foot. Nearshore waters a light chop, becoming
smooth to a light chop.
.MONDAY...East to southeast winds 5 to 10 knots, becoming light
and variable. Seas around 1 foot, subsiding to 1 foot or less.
Nearshore waters smooth to a light chop, becoming smooth.
.MONDAY NIGHT...Variable winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth.
.TUESDAY...Variable winds near 5 knots, becoming northwest and
increasing to 5 to 10 knots. Seas 1 foot or less. Nearshore
waters smooth, becoming smooth to a light chop.
.TUESDAY NIGHT...Northwest winds 5 to 10 knots. Seas 1 foot or
less. Nearshore waters smooth to a light chop.
.WEDNESDAY...West to northwest winds 5 to 10 knots. Seas 1 foot
or less. Nearshore waters smooth to a light chop. A slight chance
of showers and thunderstorms.
.WEDNESDAY NIGHT...West to northwest winds 5 to 10 knots,
becoming southwest to west and decreasing to near 5 knots. Seas 1
foot or less. Nearshore waters smooth to a light chop, becoming
smooth. A slight chance of showers and thunderstorms.
.THURSDAY...South to southwest winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. A slight chance of showers.
.THURSDAY NIGHT...Southwest 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. A slight chance of showers and
thunderstorms.
.FRIDAY NIGHT...Southeast winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. A slight chance of showers.

$$

GMZ042>044-170830-
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-
429 PM EDT Sun Aug 16 2026

.TONIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet. Nearshore
waters smooth to a light chop.
.MONDAY...East to southeast winds 5 to 10 knots, becoming variable.
Seas 1 to 2 feet. Nearshore waters smooth to a light chop,
becoming smooth.
.MONDAY NIGHT...Variable winds near 5 knots. Seas around 1 foot.
Nearshore waters smooth.
.TUESDAY...Variable winds near 5 knots, becoming northwest and
increasing to 5 to 10 knots. Seas 1 foot or less. Nearshore
waters smooth, becoming smooth to a light chop.
.TUESDAY NIGHT...Northwest winds 5 to 10 knots. Seas 1 foot or
less. Nearshore waters smooth to a light chop, becoming smooth.
.WEDNESDAY...West to northwest winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. A slight chance of showers and
thunderstorms.
.WEDNESDAY NIGHT...West to northwest winds 5 to 10 knots,
becoming southwest to west and decreasing to near 5 knots. Seas 1
foot or less. Nearshore waters smooth to a light chop, becoming
smooth. A slight chance of showers.
.THURSDAY...South to southwest winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth.
.THURSDAY NIGHT...Southeast to south winds near 5 knots. Seas 1
foot or less. Nearshore waters smooth. A slight chance of showers.
.FRIDAY...Southeast to south winds near 5 knots. Seas around
1 foot. Nearshore waters smooth. A slight chance of showers.
.FRIDAY NIGHT...East to southeast winds near 5 knots. Seas 1 foot
or less. Nearshore waters smooth. A slight chance of showers.

$$

GMZ052>055-072>075-170830-
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-
429 PM EDT Sun Aug 16 2026

.TONIGHT...East winds near 10 knots, decreasing to 5 to 10 knots.
Seas 2 to 3 feet, subsiding to 1 to 2 feet. Wave Detail: East 3
feet at 5 seconds.
.MONDAY...East winds 5 to 10 knots. Seas 1 to 2 feet. Wave
Detail: East 2 feet at 5 seconds.
.MONDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet. Wave
Detail: East 2 feet at 4 seconds.
.TUESDAY...East winds near 5 knots, becoming variable. Seas
around 1 foot.
.TUESDAY NIGHT...Variable winds near 5 knots, becoming northwest.
Seas 1 foot or less.
.WEDNESDAY...Variable winds near 5 knots. Seas 1 foot or less.
.WEDNESDAY NIGHT...Variable winds near 5 knots, becoming
southeast to south. Seas 1 foot or less.
.THURSDAY...Southeast to south winds near 5 knots, becoming east
to southeast. Seas 1 foot or less.
.THURSDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
around 1 foot. A slight chance of showers.
.FRIDAY...East to southeast winds near 5 knots. Seas around
1 foot.
.FRIDAY NIGHT...East to southeast winds 5 to 10 knots. Seas 1 to
2 feet. A slight chance of showers.

$$

GMZ033-034-170830-
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-
429 PM EDT Sun Aug 16 2026

.TONIGHT...East winds near 10 knots early, decreasing to 5 to 10
knots. Seas 1 foot or less. Wave Detail: East 1 foot at 3 seconds.
.MONDAY...East winds 5 to 10 knots, becoming north to northeast.
Seas 1 foot or less. Wave Detail: East 1 foot at 3 seconds.
.MONDAY NIGHT...North to northeast winds near 5 knots. Seas
1 foot or less.
.TUESDAY...North winds near 5 knots, becoming northwest to north.
Seas 1 foot or less.
.TUESDAY NIGHT...Northwest winds 5 to 10 knots, decreasing to near
5 knots. Seas around 1 foot.
.WEDNESDAY...West to northwest winds near 5 knots. Seas around
1 foot. A slight chance of showers and thunderstorms.
.WEDNESDAY NIGHT...West to northwest winds 5 to 10 knots. Seas
around 1 foot. A slight chance of showers and thunderstorms.
.THURSDAY...West winds near 5 knots. Seas around 1 foot. A slight
chance of showers.
.THURSDAY NIGHT...West to northwest winds near 5 knots, becoming
variable. Seas around 1 foot. A slight chance of showers and
thunderstorms.
.FRIDAY...Variable winds near 5 knots, becoming east to southeast.
Seas around 1 foot. A slight chance of showers.
.FRIDAY NIGHT...East to southeast winds near 5 knots. Seas around
1 foot. A slight chance of showers and thunderstorms.

$$