215
FZUS52 KKEY 182025
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
425 PM EDT Fri Sep 18 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.

GMZ005-190830-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
425 PM EDT Fri Sep 18 2026

.SYNOPSIS...
Light to gentle breezes will continue through the weekend. In
addition, an increasingly wet weather pattern will develop across
the Florida Keys coastal waters through early next week, as an
upper-level low retrogrades westward across the Florida Peninsula
and eventually slides into the Gulf this weekend. As a result,
scattered to occasional numerous showers and thunderstorms will be
a daily occurence, with gusty winds, lightning strikes, blinding
downpours, and locally hazardous seas being the main hazards
mariners could encounter in the vicinity of this activity. The
upper-level low is forecast to move out of the area early next
week, with winds becoming more southerly and breezes remaining
light to gentle. Rain chances will also continue to remain
elevated into next week, as deep moisture lingers across the
Florida Keys coastal waters in the wake of the departing weather
disturbance.

The Approximate Shoreward Edge of the Gulf Stream as of September
15, 2026...

64 NM south-southeast of Dry Tortugas Light, on Loggerhead Key
40 NM south-southeast of Cosgrove Shoal Light, off the Marquesas Keys
36 NM south-southeast of Sand Key Light, off Key West
35 NM southeast of Looe Key, off Big Pine Key
28 NM southeast of Sombrero Key Light, off Marathon
15 NM east-southeast of Alligator Reef Light, off Islamorada
 8 NM east-southeast of Molasses Reef Light, off Key Largo
 5 NM east-southeast of Carysfort Reef Light, off Ocean Reef

Gulf Stream Information Courtesy of the Naval Oceanographic Office.

$$

GMZ031-190830-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
425 PM EDT Fri Sep 18 2026

.TONIGHT...Northeast to east winds 5 to 10 knots. Bay waters
smooth to a light chop. A chance of showers and thunderstorms.
.SATURDAY...East winds near 5 knots. Bay waters smooth. Showers
likely with a chance of thunderstorms.
.SATURDAY NIGHT...Southeast winds 5 to 10 knots. Bay waters
smooth to a light chop. A chance of showers and thunderstorms.
.SUNDAY...South winds near 5 knots. Bay waters smooth. Showers
likely with a chance of thunderstorms.
.SUNDAY NIGHT...South winds 5 to 10 knots. Bay waters smooth to a
light chop. A chance of showers and thunderstorms.
.MONDAY...South to southwest winds near 5 knots. Bay waters
smooth. Showers likely with a chance of thunderstorms.
.MONDAY NIGHT...Southeast to south winds 5 to 10 knots, increasing
to near 10 knots. Bay waters smooth to a light chop, becoming a
light chop. Showers likely with a chance of thunderstorms.
.TUESDAY AND TUESDAY NIGHT...Southeast to south winds near 10
knots. Bay waters a light chop. Showers and thunderstorms likely.
.WEDNESDAY AND WEDNESDAY NIGHT...Southeast to south winds 5 to 10
knots. Bay waters smooth to a light chop. Showers likely with a
chance of thunderstorms.

$$

GMZ032-035-190830-
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-
425 PM EDT Fri Sep 18 2026

.TONIGHT...Northeast to east winds 5 to 10 knots. Seas 1 foot or
less. Nearshore waters smooth to a light chop. Showers likely with
a chance of thunderstorms.
.SATURDAY...East winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth. Showers likely with a chance of
thunderstorms.
.SATURDAY NIGHT...East winds 5 to 10 knots, becoming southeast.
Seas 1 foot or less. Nearshore waters smooth to a light chop.
Showers likely with a chance of thunderstorms.
.SUNDAY...South winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth. Showers likely with a chance of
thunderstorms.
.SUNDAY NIGHT...South winds 5 to 10 knots. Seas 1 foot or less.
Nearshore waters smooth to a light chop. Showers likely with a
chance of thunderstorms.
.MONDAY...South to southwest winds 5 to 10 knots. Seas 1 foot or
less. Nearshore waters smooth to a light chop. Showers likely
with a chance of thunderstorms.
.MONDAY NIGHT...South winds 5 to 10 knots, increasing to near 10
knots. Seas 1 foot or less. Nearshore waters smooth to a light
chop, becoming a light chop. Showers likely with a chance of
thunderstorms.
.TUESDAY...Southeast to south winds 5 to 10 knots. Seas 1 foot or
less. Nearshore waters smooth to a light chop. Showers and
thunderstorms likely.
.TUESDAY NIGHT...Southeast winds 5 to 10 knots, 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.
Showers likely with a chance of thunderstorms.
.WEDNESDAY...Southeast to south winds 5 to 10 knots. Seas around 1
foot. Nearshore waters smooth to a light chop. Showers likely
with a chance of thunderstorms.
.WEDNESDAY NIGHT...Southeast to south winds 5 to 10 knots. Seas 1
foot or less. Nearshore waters smooth to a light chop. Showers
likely with a chance of thunderstorms.

$$

GMZ042>044-190830-
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-
425 PM EDT Fri Sep 18 2026

.TONIGHT...Northeast to east winds 5 to 10 knots. Seas around 1
foot. Nearshore waters smooth to a light chop. Showers likely
with a chance of thunderstorms.
.SATURDAY...East winds near 5 knots. Seas around 1 foot.
Nearshore waters smooth. A chance of showers and thunderstorms.
.SATURDAY NIGHT...East winds 5 to 10 knots, becoming southeast to
south. Seas around 1 foot. Nearshore waters smooth to a light
chop. Showers likely with a chance of thunderstorms.
.SUNDAY...South to southwest winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. Showers likely with a chance of
thunderstorms.
.SUNDAY NIGHT...South winds 5 to 10 knots. Seas around 1 foot.
Nearshore waters smooth to a light chop. A chance of showers and
thunderstorms.
.MONDAY...South winds 5 to 10 knots. Seas around 1 foot.
Nearshore waters smooth to a light chop. Showers likely with a
chance of thunderstorms.
.MONDAY NIGHT...Southeast to south winds 5 to 10 knots, 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.
Showers likely with a chance of thunderstorms.
.TUESDAY...Southeast to south winds 5 to 10 knots. Seas around 1
foot. Nearshore waters smooth to a light chop. Showers likely with
a chance of thunderstorms.
.TUESDAY NIGHT...Southeast to south winds 5 to 10 knots,
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. Showers likely with a chance of thunderstorms.
.WEDNESDAY...Southeast to south winds 5 to 10 knots. Seas around
1 foot. Nearshore waters smooth to a light chop. Showers likely
with a chance of thunderstorms.
.WEDNESDAY NIGHT...Southeast to south winds 5 to 10 knots,
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. Showers likely with a chance of thunderstorms.

$$

GMZ052>055-072>075-190830-
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-
425 PM EDT Fri Sep 18 2026

.TONIGHT...East winds 5 to 10 knots. Seas 1 to 2 feet. Wave
Detail: Northeast to east 2 feet at 5 seconds. Showers likely
with a chance of thunderstorms.
.SATURDAY...East winds near 5 knots. Seas around 1 foot. Wave
Detail: East 1 foot at 4 seconds. A chance of showers and
thunderstorms.
.SATURDAY NIGHT...East winds 5 to 10 knots, becoming southeast to
south. Seas 1 to 2 feet. Wave Detail: East to southeast 1 foot at
4 seconds. Showers likely with a chance of thunderstorms.
.SUNDAY...South to southwest winds near 5 knots. Seas around
1 foot. Showers likely with a chance of thunderstorms.
.SUNDAY NIGHT...South winds 5 to 10 knots. Seas 1 to 2 feet. A
chance of showers and thunderstorms.
.MONDAY...South winds 5 to 10 knots. Seas 1 to 2 feet. Showers
likely with a chance of thunderstorms.
.MONDAY NIGHT...Southeast to south winds 5 to 10 knots, increasing
to near 10 knots. Seas 1 to 2 feet, building to around 2 feet.
Showers likely with a chance of thunderstorms.
.TUESDAY...Southeast to south winds 5 to 10 knots. Seas 1 to 2 feet.
Showers likely with a chance of thunderstorms.
.TUESDAY NIGHT...Southeast to south winds near 10 knots. Seas
around 2 feet. Showers likely with a chance of thunderstorms.
.WEDNESDAY...Southeast to south winds 5 to 10 knots. Seas 1 to
2 feet. Showers likely with a chance of thunderstorms.
.WEDNESDAY NIGHT...Southeast to south winds near 10 knots. Seas
around 2 feet. Showers likely with a chance of thunderstorms

$$

GMZ033-034-190830-
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-
425 PM EDT Fri Sep 18 2026

.TONIGHT...Northeast to east winds 5 to 10 knots. Seas around
1 foot. Wave Detail: Northeast to east 1 foot at 4 seconds.
Showers likely with a chance of thunderstorms.
.SATURDAY...East winds near 5 knots. Seas 1 foot or less. Wave
Detail: East 1 foot at 3 seconds. Showers likely with a chance of
thunderstorms.
.SATURDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
1 around 1 foot. Wave Detail: East 1 foot at 3 seconds. A chance
of showers and thunderstorms.
.SUNDAY...Southeast to south winds near 5 knots. Seas 1 foot or
less. Showers likely with a chance of thunderstorms.
.SUNDAY NIGHT...South to southwest winds near 5 knots, becoming
southeast to south. Seas 1 foot or less. A chance of showers and
thunderstorms.
.MONDAY...South to southwest winds 5 to 10 knots. Seas around
1 foot. Showers likely with a chance of thunderstorms.
.MONDAY NIGHT...South winds 5 to 10 knots, increasing to near 10
knots. Seas around 1 foot, building to 1 to 2 feet. Showers
likely with a chance of thunderstorms.
.TUESDAY...Southeast to south winds 5 to 10 knots. Seas around 1
foot. Showers and thunderstorms likely.
.TUESDAY NIGHT...Southeast winds 5 to 10 knots. Seas around
1 foot. Showers likely with a chance of thunderstorms.
.WEDNESDAY...Southeast winds 5 to 10 knots. Seas around 1 foot.
Showers likely with a chance of thunderstorms.
.WEDNESDAY NIGHT...Southeast winds 5 to 10 knots. Seas around 1
foot. Showers likely with a chance of thunderstorms.

$$

BT/RG