183
FZUS52 KKEY 132031
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
431 PM EDT Thu Aug 13 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.

GMZ005-140845-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
431 PM EDT Thu Aug 13 2026

.SYNOPSIS...Weak high pressure over the region will promote a
brief period of northeast to east breezes this evening before
shifting to the east to southeast for overnight. As the high
restrengthens and builds westward, breezes will somewhat freshen
for Friday through the weekend. A weak frontal boundary will
approach the Florida Peninsula early next week, allowing breezes
to slacken once again, becoming light and variable at times.

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.

$$

GMZ031-140845-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
431 PM EDT Thu Aug 13 2026

.TONIGHT...East to southeast 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.
.FRIDAY...East winds near 10 knots, increasing to 10 to 15 knots.
Bay waters a light chop, becoming a light to moderate chop. A
chance of showers and thunderstorms.
.FRIDAY NIGHT...East to southeast winds near 15 knots. Bay waters
a moderate chop. A chance of showers and thunderstorms.
.SATURDAY...East to southeast winds 10 to 15 knots, decreasing to
near 10 knots. Bay waters a light to moderate chop, becoming a
light chop. A chance of showers and thunderstorms.
.SATURDAY NIGHT...East to southeast winds 10 to 15 knots. Bay
waters a light to moderate chop. A slight chance of showers and
thunderstorms.
.SUNDAY...East to southeast winds near 10 knots. Bay waters a
light chop.
.SUNDAY NIGHT...East winds 10 to 15 knots, becoming 5 to 10 knots
after midnight. Bay waters a light to moderate chop, becoming
smooth to a light chop.
.MONDAY...East winds near 5 knots, becoming southeast in the
afternoon. Bay waters smooth, becoming smooth to a light chop. A
slight chance of showers and thunderstorms.
.MONDAY NIGHT...East winds 5 to 10 knots, becoming north to
northeast after midnight. Bay waters smooth to a light chop,
becoming smooth. A slight chance of showers.
.TUESDAY...Northeast to east winds near 5 knots, becoming south
in the afternoon. Bay waters smooth, becoming smooth to a light
chop. A slight chance of showers and thunderstorms.
.TUESDAY NIGHT...Southeast to south winds 5 to 10 knots. Bay
waters smooth to a light chop.

$$

GMZ032-035-140845-
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-
431 PM EDT Thu Aug 13 2026

.TONIGHT...Northeast to east winds 5 to 10 knots, becoming east
to southeast and increasing to near 10 knots. Seas 1 foot or less,
building to around 1 foot. Nearshore waters smooth to a light
chop, becoming a light chop. A slight chance of showers and
thunderstorms.
.FRIDAY...East to southeast winds near 10 knots, increasing to 10
to 15 knots. Seas around 1 foot, building to 1 to 2 feet.
Nearshore waters a light to moderate chop. A chance of showers and
thunderstorms.
.FRIDAY NIGHT...East to southeast winds near 15 knots. Seas
1 to 2 feet, except around 2 feet west of the Marquesas Keys.
Nearshore waters a moderate chop. A chance of showers and
thunderstorms.
.SATURDAY...East to southeast winds 10 to 15 knots, decreasing to
near 10 knots. Seas 1 to 2 feet. Nearshore waters a light to
moderate chop, becoming a light chop. A chance of showers and
thunderstorms.
.SATURDAY NIGHT...East to southeast winds 10 to 15 knots. Seas
1 to 2 feet. Nearshore waters a light to moderate chop. A chance
of showers with a slight chance of thunderstorms.
.SUNDAY...East to southeast winds near 10 knots. Seas 1 foot or
less. Nearshore waters a light chop.
.SUNDAY NIGHT...East winds 10 to 15 knots, becoming 5 to 10 knots
after midnight. Seas 1 foot or less. Nearshore waters a light to
moderate chop, becoming smooth to a light chop.
.MONDAY...East winds 5 to 10 knots. Seas 1 foot or less.
Nearshore waters smooth to a light chop. A slight chance of
showers and thunderstorms.
.MONDAY NIGHT...Northeast winds 5 to 10 knots. Seas 1 foot or
less. Nearshore waters smooth to a light chop. A slight chance of
showers and thunderstorms.
.TUESDAY...East winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth. A slight chance of showers and
thunderstorms.
.TUESDAY NIGHT...East winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth. A slight chance of showers.

$$

GMZ042>044-140845-
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-
431 PM EDT Thu Aug 13 2026

.TONIGHT...Northeast to east winds 5 to 10 knots, becoming east
to southeast and increasing to near 10 knots. Seas around 1 foot,
building to 1 to 2 feet. Nearshore waters smooth to a light chop,
becoming a light chop. A slight chance of showers and
thunderstorms.
.FRIDAY...East winds near 10 knots, increasing to 10 to 15 knots.
Seas 1 to 2 feet, building to around 2 feet. Nearshore waters a
light chop, becoming a light to moderate chop. A chance of showers
and thunderstorms.
.FRIDAY NIGHT...East to southeast winds near 15 knots. Seas 2 to
3 feet. Nearshore waters a moderate chop. A chance of showers and
thunderstorms.
.SATURDAY...East to southeast winds 10 to 15 knots, decreasing to
near 10 knots. Seas 2 to 3 feet, subsiding to around 2 feet.
Nearshore waters a light to moderate chop, becoming a light chop.
A chance of showers and thunderstorms.
.SATURDAY NIGHT...East to southeast winds 10 to 15 knots. Seas
around 2 feet. Nearshore waters a light to moderate chop. A
slight chance of showers and thunderstorms.
.SUNDAY...East winds 10 to 15 knots. Seas 2 to 3 feet. Nearshore
waters a light to moderate chop.
.SUNDAY NIGHT...East winds 10 to 15 knots. Seas 1 to 2 feet.
Nearshore waters a light to moderate chop.
.MONDAY...East winds 5 to 10 knots. Seas 1 to 2 feet. Nearshore
waters smooth to a light chop. A slight chance of showers.
.MONDAY NIGHT...Northeast to east winds 5 to 10 knots. Seas
around 1 foot. Nearshore waters smooth to a light chop. A slight
chance of showers and thunderstorms.
.TUESDAY...East winds near 5 knots. Seas around 1 foot. Nearshore
waters smooth. A slight chance of showers.
.TUESDAY NIGHT...East to southeast winds near 5 knots. Seas
1 foot or less. Nearshore waters smooth. A slight chance of
showers.

$$

GMZ052>055-072>075-140845-
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-
431 PM EDT Thu Aug 13 2026

.TONIGHT...Northeast to east winds 5 to 10 knots, becoming east to
southeast and increasing to near 10 knots. Seas 1 to 2 feet,
building to around 2 feet. Wave Detail: East 2 feet at 4 seconds.
A slight chance of showers and thunderstorms.
.FRIDAY...East winds near 10 knots, increasing to 10 to 15 knots.
Seas around 2 feet, building to 2 to 3 feet. Wave Detail: East 2
feet at 4 seconds. A chance of showers and thunderstorms.
.FRIDAY NIGHT...East to southeast winds near 15 knots. Seas 2 to
4 feet, occasionally to 5 feet. Wave Detail: East 3 feet at 4
seconds. A chance of showers and thunderstorms.
.SATURDAY...East to southeast winds 10 to 15 knots, decreasing to
near 10 knots. Seas 2 to 4 feet, occasionally to 5 feet,
subsiding to 2 to 3 feet. A chance of showers and thunderstorms.
.SATURDAY NIGHT...East to southeast winds 10 to 15 knots. Seas 2
to 3 feet. A slight chance of showers and thunderstorms.
.SUNDAY...East winds 10 to 15 knots. Seas 2 to 3 feet.
.SUNDAY NIGHT...East winds 10 to 15 knots. Seas 2 to 4 feet,
occasionally to 5 feet.
.MONDAY...East winds 10 to 15 knots, becoming northeast to east
5 to 10 knots in the afternoon. Seas 2 to 3 feet.
.MONDAY NIGHT...Northeast to east winds 5 to 10 knots. Seas 1 to
2 feet. A slight chance of showers.
.TUESDAY...East winds 5 to 10 knots. Seas 1 to 2 feet. A slight
chance of showers.
.TUESDAY NIGHT...East winds 5 to 10 knots. Seas 1 foot or less. A
slight chance of showers.

$$

GMZ033-034-140845-
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-
431 PM EDT Thu Aug 13 2026

.TONIGHT...Northeast to east winds 5 to 10 knots, becoming east
to southeast and increasing to near 10 knots. Seas around 1 foot.
Wave Detail: North to northeast 1 foot at 3 seconds.A slight
chance of showers and thunderstorms.
.FRIDAY...Northeast to to east winds 5 to 10 knots. Seas around 1
foot. Wave Detail: East to southeast 1 foot at 3 seconds. A
chance of showers and thunderstorms.
.FRIDAY NIGHT...East winds near 10 knots, increasing to 10 to 15
knots. Seas 1 to 2 feet, building to around 2 feet. Wave Detail:
East 2 feet at 3 seconds. A chance of showers and thunderstorms.
.SATURDAY...East to southeast winds near 10 knots. Seas around 2
feet. A chance of showers and thunderstorms.
.SATURDAY NIGHT...East to southeast winds near 10 knots,
increasing to 10 to 15 knots. Seas around 2 feet, building to 2
to 3 feet. A chance of showers with a slight chance of
thunderstorms.
.SUNDAY...East to southeast winds 5 to 10 knots. Seas 1 to
2 feet. A chance of thunderstorms with a slight chance of
showers.
.SUNDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet.
.MONDAY...Northeast to east winds 5 to 10 knots. Seas 1 foot or
less. A slight chance of showers.
.MONDAY NIGHT...North to northeast winds 5 to 10 knots. Seas
1 foot or less. A slight chance of showers and thunderstorms.
.TUESDAY...North to northeast winds near 5 knots. Seas around
1 foot. A slight chance of showers.
.TUESDAY NIGHT...North winds near 5 knots, becoming northeast to
east after midnight. Seas around 1 foot. A slight chance of
showers and thunderstorms.

$$

MJV/BT