055
FZUS52 KKEY 172019
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
419 PM EDT Mon Aug 17 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.

GMZ005-180830-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
419 PM EDT Mon Aug 17 2026

.SYNOPSIS...
A nebulous flow pattern will support gentle breezes becoming
light and variable at times for the next several days. A Saharan
Air Layer will keep shower and thunderstorm chances at near-nil
through Tuesday night, with only a slight chance of rain and
thunder expected for Wednesday through Saturday.

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.

$$

GMZ031-180830-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
419 PM EDT Mon Aug 17 2026

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

$$

GMZ032-035-180830-
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-
419 PM EDT Mon Aug 17 2026

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

$$

GMZ042>044-180830-
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-
419 PM EDT Mon Aug 17 2026

.TONIGHT...Southeast winds near 5 knots, becoming variable. Seas
around 1 foot. Nearshore waters smooth.
.TUESDAY...Variable winds near 5 knots, becoming west to northwest.
Seas around 1 foot. Nearshore waters smooth.
.TUESDAY NIGHT...West to northwest winds 5 to 10 knots. Seas
around 1 foot. 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,
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...Variable winds near 5 knots, becoming southwest. Seas
1 foot or less. Nearshore waters smooth. A slight chance of
showers and thunderstorms.
.THURSDAY NIGHT...Southeast to south winds 5 to 10 knots. Seas
around 1 foot. Nearshore waters smooth to a light chop. A slight
chance of showers.
.FRIDAY...Southeast to south winds near 5 knots. Seas around 1
foot. Nearshore waters smooth.
.FRIDAY NIGHT...Southeast winds 5 to 10 knots. Seas around 1
foot. Nearshore waters smooth to a light chop. A slight chance of
showers.
.SATURDAY...Southeast to south winds near 5 knots. Seas around
1 foot. Nearshore waters smooth. A slight chance of showers.
.SATURDAY NIGHT...Southeast winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. A slight chance of showers.

$$

GMZ052>055-072>075-180830-
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-
419 PM EDT Mon Aug 17 2026

.TONIGHT...East winds 5 to 10 knots, becoming variable near 5
knots. Seas 1 to 2 feet. Wave Detail: East 2 feet at 4 seconds.
.TUESDAY...Variable winds near 5 knots, becoming northwest to
north. Seas around 1 foot. Wave Detail: East to southeast 1 foot
at 4 seconds.
.TUESDAY NIGHT...Northwest to north winds 5 to 10 knots. Seas
1 to 2 feet. Wave Detail: East 1 foot at 4 seconds.
.WEDNESDAY...Northwest winds 5 to 10 knots. Seas 1 to 2 feet.
.WEDNESDAY NIGHT...Northwest winds 5 to 10 knots, becoming south
after midnight. Seas around 1 foot.
.THURSDAY...Southeast to south winds near 5 knots. Seas around 1
foot.
.THURSDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
1 to 2 feet. A slight chance of showers.
.FRIDAY...East to southeast winds 5 to 10 knots. Seas 1 to
2 feet.
.FRIDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
1 to 2 feet. A slight chance of showers.
.SATURDAY...Southeast to south near 5 knots. Seas around 1 foot.
.SATURDAY NIGHT...Southeast winds 5 to 10 knots. Seas 1 to 2 feet.
A slight chance of showers.

$$

GMZ033-034-180830-
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-
419 PM EDT Mon Aug 17 2026

.TONIGHT...Variable winds near 5 knots, becoming northwest to
north. Seas 1 foot or less.
.TUESDAY...Northwest to north winds 5 to 10 knots. Seas around 1
foot. Wave Detail: Northwest to north 1 foot at 3 seconds.
.TUESDAY NIGHT...Northwest to north winds 5 to 10 knots. Seas
around 1 foot. Wave Detail: Northwest to north 1 foot at 3
seconds.
.WEDNESDAY...West to northwest winds 5 to 10 knots. Seas 1 to 2
feet. A slight chance of showers and thunderstorms.
.WEDNESDAY NIGHT...West to northwest winds 5 to 10 knots,
decreasing to near 5 knots. Seas around 1 foot. A slight chance
of showers and thunderstorms.
.THURSDAY...West to northwest winds near 5 knots. Seas around 1
foot. A slight chance of showers and thunderstorms.
.THURSDAY NIGHT...Northwest to north winds near 5 knots, becoming
variable. Seas around 1 foot. A slight chance of showers and
thunderstorms.
.FRIDAY...South to southwest winds near 5 knots, becoming variable.
Seas around 1 foot. A slight chance of showers.
.FRIDAY NIGHT...Variable winds near 5 knots, becoming southeast to
south. Seas around 1 foot. A slight chance of showers and
thunderstorms.
.SATURDAY...South to southwest winds near 5 knots, becoming
variable. Seas around 1 foot. A slight chance of showers.
.SATURDAY NIGHT...Variable winds near 5 knots, becoming southeast
to south. Seas 1 foot or less. A slight chance of showers and
thunderstorms.

$$

BT/AJP