915
FZUS52 KKEY 171427
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
1027 AM 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.

GMZ005-180200-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
1027 AM EDT Mon Aug 17 2026

.SYNOPSIS...
A nebulous flow pattern will support gentle east to
southeasterly 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 the latter
half of the work week.

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.

$$

GMZ031-180200-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
1027 AM EDT Mon Aug 17 2026

.THIS AFTERNOON...Southeast to south winds near 5 knots, becoming
south to southwest. Bay waters smooth.
.TONIGHT...Southwest to west winds near 5 knots. Bay waters
smooth.
.TUESDAY...West to northwest winds 5 to 10 knots, increasing to
west 10 to 15 knots. Bay waters smooth to a light chop, becoming
a light to moderate chop.
.TUESDAY NIGHT...West to northwest winds decreasing to 5 to 10
knots. Bay waters 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 winds 5 to 10 knots. Bay waters smooth
to a light chop. A slight chance of showers and thunderstorms.

$$

GMZ032-035-180200-
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-
1027 AM EDT Mon Aug 17 2026

.THIS AFTERNOON...East to southeast winds 5 to 10 knots, becoming
variable near 5 knots. Seas around 1 foot. Nearshore waters
smooth to a light chop, becoming smooth.
.TONIGHT...Variable winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth.
.TUESDAY...Variable winds near 5 knots, becoming west to
northwest 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 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 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 winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. A slight chance of showers and
thunderstorms.

$$

GMZ042>044-180200-
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-
1027 AM EDT Mon Aug 17 2026

.THIS AFTERNOON...East to southeast winds 5 to 10 knots, becoming
variable near 5 knots. Seas around 2 feet, subsiding to 1 to 2
feet. Nearshore waters smooth to a light chop, becoming smooth.
.TONIGHT...East winds near 5 knots. 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 winds near 5 knots. Seas around 1 foot.
Nearshore waters smooth. A slight chance of showers.
.FRIDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
around 1 foot. Nearshore waters smooth to a light chop. A slight
chance of showers and thunderstorms.

$$

GMZ052>055-072>075-180200-
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-
1027 AM EDT Mon Aug 17 2026

.THIS AFTERNOON...East to southeast winds near 10 knots,
decreasing to 5 to 10 knots. Seas 2 to 3 feet, subsiding to around
2 feet. Wave Detail: East 3 feet at 5 seconds.
.TONIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet. Wave
Detail: East 2 feet at 4 seconds.
.TUESDAY...Variable winds near 5 knots, becoming northwest to
north in the afternoon. 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
around 1 foot.
.WEDNESDAY...Northwest winds 5 to 10 knots. Seas around 1 foot.
.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
around 1 foot. A slight chance of showers and thunderstorms.

$$

GMZ033-034-180200-
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-
1027 AM EDT Mon Aug 17 2026

.THIS AFTERNOON...East winds 5 to 10 knots, becoming variable
near 5 knots. Seas 1 to 2 feet, subsiding to around 1 foot. Wave
Detail: East to southeast 1 foot at 3 seconds.
.TONIGHT...North to northeast winds near 5 knots. Seas 1 foot or
less.
.TUESDAY...Northwest to north winds 5 to 10 knots. Seas 1 foot or
less. Wave Detail: Northwest to north 1 foot at 3 seconds.
.TUESDAY NIGHT...Northwest to north winds 5 to 10 knots. Seas
around 1 foot.
.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 1 to 2 feet. A slight chance of
showers and thunderstorms.
.THURSDAY...West to northwest winds near 5 knots. Seas 1 to
2 feet. A slight chance of showers and thunderstorms.
.THURSDAY NIGHT...Northwest to north winds near 5 knots, becoming
variable. Seas 1 to 2 feet. A slight chance of showers and
thunderstorms.
.FRIDAY...Southeast to south winds near 5 knots. 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.

$$

BT/AJP