856
FZUS52 KKEY 180834 CCA
CWFKEY

Coastal Waters Forecast for the Florida Keys...CORRECTED
National Weather Service Key West FL
434 AM EDT Sat Jul 18 2026

Corrected grammatical error in synopsis.

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.

GMZ005-182045-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
434 AM EDT Sat Jul 18 2026

.SYNOPSIS...
A closed upper level low will continue spinning just off the West
Coast of Florida today. This low is caught in between a split
ridge with one piece of the ridge across the western North
Atlantic and the other across the western Gulf. The ridge over the
Atlantic will begin to slowly influence the Keys coastal waters
over the next several days. Therefore, expect mainly southeasterly
breezes to continue into at least early next week. Breezes will
tend to surge overnight, then lull in the afternoon.

The Approximate Shoreward Edge of the Gulf Stream as of
July 17, 2026...

49 NM South of Dry Tortugas Light...on Loggerhead Key.
51 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
38 NM South of Sand Key Light...off Key West.
22 NM South of Looe Key...off Big Pine Key.
13 NM South of Sombrero Key Light...off Marathon.
 6 NM Southeast of Alligator Reef Light...off Islamorada.
 2 NM Southeast of Molasses Reef Light...off Key Largo.
 1 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.

$$

GMZ031-182045-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
434 AM EDT Sat Jul 18 2026

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

$$

GMZ032-035-182045-
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-
434 AM EDT Sat Jul 18 2026

.TODAY...Southeast to south winds near 10 knots. Seas around
1 foot, except 1 to 2 feet west of the Marquesas Keys. Nearshore
waters a light chop. A slight chance of showers and thunderstorms.
.TONIGHT...Southeast winds 10 to 15 knots, increasing to near 15
knots. Seas 1 to 2 feet, except building to 2 to 3 feet west of
the Marquesas Keys. Nearshore waters a light to moderate chop,
becoming a moderate chop. A slight chance of showers and
thunderstorms.
.SUNDAY...Southeast to south winds near 15 knots, decreasing to 5
to 10 knots in the afternoon. Seas 1 to 2 feet, subsiding to
around 1 foot. West of the Marquesas Keys, seas 2 to 3 feet,
subsiding to 1 to 2 feet. Nearshore waters a moderate chop,
becoming smooth to a light chop. A chance of showers with a slight
chance of thunderstorms.
.SUNDAY NIGHT...Southeast to south winds 5 to 10 knots, increasing
to 10 to 15 knots after midnight. Seas around 1 foot, except 1 to
2 feet west of the Marquesas Keys. Nearshore waters smooth to a
light chop, becoming a light to moderate chop. A slight chance of
showers and thunderstorms.
.MONDAY...Southeast to south 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. A slight chance of showers and
thunderstorms.
.MONDAY NIGHT...Southeast winds 5 to 10 knots, increasing to
10 to 15 knots after midnight. Seas around 1 foot, except
building to 1 to 2 feet west of the Marquesas Keys. Nearshore
waters smooth to a light chop, becoming a light to moderate chop.
.TUESDAY...Southeast winds 10 to 15 knots, becoming east to
southeast and decreasing to near 10 knots. Seas around 1 foot,
except around 2 feet west of the Marquesas Keys. Nearshore waters
a light to moderate chop, becoming a light chop.
.TUESDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
1 foot or less. Nearshore waters smooth to a light chop.
.WEDNESDAY...East to southeast winds 5 to 10 knots. Seas 1 foot
or less. Nearshore waters smooth to a light chop.
.WEDNESDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
1 foot or less. Nearshore waters smooth to a light chop.

$$

GMZ042>044-182045-
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-
434 AM EDT Sat Jul 18 2026

.TODAY...Southeast to south winds 10 to 15 knots, becoming
southeast and decreasing to near 10 knots. Seas around 2 feet.
Nearshore waters a light to moderate chop, becoming a light chop.
A slight chance of showers and thunderstorms.
.TONIGHT...Southeast winds 10 to 15 knots, increasing to near 15
knots. Seas 2 to 3 feet. Nearshore waters a light to moderate
chop, becoming a moderate chop. A slight chance of showers and
thunderstorms.
.SUNDAY...Southeast to south winds near 15 knots, decreasing to 5
to 10 knots in the afternoon. Seas 2 to 3 feet, subsiding to 1 to
2 feet. Nearshore waters a moderate chop, becoming smooth to a
light chop. A slight chance of showers and thunderstorms.
.SUNDAY NIGHT...Southeast to south winds 5 to 10 knots, increasing
to 10 to 15 knots after midnight. Seas 1 to 2 feet, building to
around 2 feet. Nearshore waters smooth to a light chop, becoming a
light to moderate chop. A slight chance of showers and
thunderstorms.
.MONDAY...Southeast to south winds near 10 knots, decreasing to 5
to 10 knots. Seas 1 to 2 feet. Nearshore waters a light chop,
becoming smooth to a light chop. A slight chance of showers and
thunderstorms.
.MONDAY NIGHT...Southeast winds 5 to 10 knots, increasing to
10 to 15 knots after midnight. Seas 1 to 2 feet, building to
around 2 feet. Nearshore waters smooth to a light chop, becoming a
light to moderate chop.
.TUESDAY...Southeast winds 10 to 15 knots, becoming east to
southeast and decreasing to near 10 knots. Seas around 2 feet,
subsiding to 1 to 2 feet. Nearshore waters a light to moderate
chop, becoming a light chop.
.TUESDAY NIGHT...East to southeast winds 5 to 10 knots. Seas 1 to
2 feet. Nearshore waters smooth to a light chop.
.WEDNESDAY...East to southeast winds 5 to 10 knots. Seas 1 to
2 feet. Nearshore waters smooth to a light chop.
.WEDNESDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
around 1 foot. Nearshore waters smooth to a light chop.

$$

GMZ052>055-072>075-182045-
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-
434 AM EDT Sat Jul 18 2026

.TODAY...Southeast winds 10 to 15 knots, becoming east to
southeast and decreasing to near 10 knots this afternoon. Seas 2
to 3 feet. Wave Detail: East to southeast 2 feet at 4 seconds. A
slight chance of showers and thunderstorms.
.TONIGHT...East to southeast winds 10 to 15 knots, becoming
southeast and increasing to near 15 knots. Seas 2 to 3 feet,
building to 2 to 4 feet, occasionally to 5 feet. Wave Detail: East
to southeast 3 feet at 4 seconds. A slight chance of showers and
thunderstorms.
.SUNDAY...Southeast to south winds 10 to 15 knots, becoming
southeast and decreasing to 5 to 10 knots in the afternoon. Seas
2 to 3 feet, subsiding to 1 to 2 feet. Wave Detail: East to
southeast 3 feet at 5 seconds. A slight chance of showers and
thunderstorms.
.SUNDAY NIGHT...Southeast winds 5 to 10 knots, becoming southeast
to south and increasing to 10 to 15 knots after midnight. Seas 1
to 2 feet, building to around 2 feet. A slight chance of showers
and thunderstorms.
.MONDAY...Southeast to south winds 10 to 15 knots, becoming east
to southeast and decreasing to 5 to 10 knots. Seas 2 to 3 feet,
subsiding to 1 to 2 feet. A slight chance of showers and
thunderstorms.
.MONDAY NIGHT...East winds 5 to 10 knots, becoming east to
southeast and increasing to 10 to 15 knots after midnight. Seas 1
to 3 feet, building to 2 to 3 feet.
.TUESDAY...East to southeast winds 10 to 15 knots, decreasing to
near 10 knots. Seas 2 to 3 feet.
.TUESDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet.
.WEDNESDAY...East to southeast winds 5 to 10 knots. Seas 1 to
2 feet.
.WEDNESDAY NIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet. A
slight chance of showers.

$$

GMZ033-034-182045-
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-
434 AM EDT Sat Jul 18 2026

.TODAY...Southeast to south winds 5 to 10 knots. Seas 1 to
2 feet. Wave Detail: Southeast to south 1 foot at 2 seconds and
northwest 1 foot at 5 seconds. A chance of showers and
thunderstorms.
.TONIGHT...Southeast winds 5 to 10 knots, becoming southeast to
south and increasing to 10 to 15 knots after midnight. Seas 1 to
2 feet, building to around 2 feet. Wave Detail: Southeast 2 feet
at 4 seconds and northwest 1 foot at 5 seconds. A chance of
showers and thunderstorms.
.SUNDAY...Southeast to south winds 10 to 15 knots, becoming south
and decreasing to 5 to 10 knots in the afternoon. Seas around 2
feet, subsiding to 1 to 2 feet. Wave Detail: Southeast 2 feet at
4 seconds and northwest 1 foot at 5 seconds. A chance of showers
and thunderstorms.
.SUNDAY NIGHT...South winds 5 to 10 knots, increasing to near 10
knots. Seas 1 to 2 feet. A chance of showers with a slight chance
of thunderstorms.
.MONDAY...South winds near 10 knots, becoming south to southwest
and decreasing to 5 to 10 knots. Seas 1 to 2 feet. A chance of
showers with a slight chance of thunderstorms.
.MONDAY NIGHT...South to southwest winds 5 to 10 knots, becoming
southeast and increasing to 10 to 15 knots after midnight. Seas
around 1 foot, building to 1 to 2 feet.
.TUESDAY...Southeast winds 10 to 15 knots, decreasing to 5 to 10
knots in the afternoon. Seas 1 to 2 feet, subsiding to around 1
foot.
.TUESDAY NIGHT...Southeast winds 5 to 10 knots. Seas around
1 foot.
.WEDNESDAY...East to southeast winds 5 to 10 knots. Seas 1 foot
or less.
.WEDNESDAY NIGHT...East to southeast winds near 5 knots. Seas
1 foot or less. A slight chance of showers.

$$

MJV