628
FZUS52 KKEY 202038
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
438 PM EDT Sun Sep 20 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.

GMZ005-210845-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
438 PM EDT Sun Sep 20 2026

.SYNOPSIS...
A wet weather pattern will persist across the Florida Keys
coastal waters for the next several days as an upper- level low
lingers in the eastern Gulf waters. As a result, the main hazards
from scattered to numerous showers and thunderstorms will be a
daily occurence with gusty winds, lightning strikes, blinding
downpours, and locally hazardous seas. Breezes will generally
remain light to gentle into the new week but brief periods of
moderate breezes may occur in the evening hours.

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.

$$

GMZ031-210845-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
438 PM EDT Sun Sep 20 2026

.TONIGHT...Variable winds near 5 knots, becoming south 5 to
10 knots late this evening and overnight. Bay waters smooth,
becoming smooth to a light chop. A chance of showers and
thunderstorms.
.MONDAY...South to southwest winds 5 to 10 knots. Bay waters
smooth to a light chop. Showers likely with a chance of
thunderstorms.
.MONDAY NIGHT...South winds 5 to 10 knots. Bay waters smooth to a
light chop. Showers likely with a chance of thunderstorms.
.TUESDAY THROUGH WEDNESDAY...Southeast to south winds 5 to 10
knots. Bay waters smooth to a light chop. Showers likely with a
chance of thunderstorms.
.WEDNESDAY NIGHT AND THURSDAY...Southeast winds near 5 knots. Bay
waters smooth. Showers likely with a chance of thunderstorms.
.THURSDAY NIGHT...East to southeast winds near 5 knots, becoming
north to northeast after midnight. Bay waters smooth. A chance of
showers and thunderstorms.
.FRIDAY...North to northeast winds near 5 knots, becoming east to
southeast near 5 knots in the afternoon. Bay waters smooth.
Showers likely with a chance of thunderstorms.
.FRIDAY NIGHT...Northeast winds near 5 knots. Bay waters smooth.
A chance of showers and thunderstorms.

$$

GMZ032-035-210845-
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-
438 PM EDT Sun Sep 20 2026

.TONIGHT...Variable winds near 5 knots, becoming south 5 to
10 knots late this evening and overnight. Seas 1 foot or less,
then 1 foot or less after midnight. Nearshore waters smooth,
becoming smooth to a light chop. A chance of showers and
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. Seas 1 foot or less.
Nearshore waters smooth to a light chop. Showers likely with a
chance of thunderstorms.
.TUESDAY THROUGH WEDNESDAY...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.
.WEDNESDAY NIGHT AND THURSDAY...Southeast winds near 5 knots.
Seas 1 foot or less. Nearshore waters smooth. Showers likely with
a chance of thunderstorms.
.THURSDAY NIGHT...East to southeast winds near 5 knots. Seas
1 foot or less. Nearshore waters smooth. A chance of showers and
thunderstorms.
.FRIDAY...Northeast winds near 5 knots. Seas 1 foot or less.
Nearshore waters smooth. A chance of showers and thunderstorms.
.FRIDAY NIGHT...Northeast to east winds near 5 knots. Seas 1 foot
or less. Nearshore waters smooth. A chance of showers and
thunderstorms.

$$

GMZ042>044-210845-
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-
438 PM EDT Sun Sep 20 2026

.TONIGHT...Variable winds near 5 knots, becoming south 5 to
10 knots late this evening and overnight. Seas 1 foot or less,
then 1 foot or less after midnight. Nearshore waters smooth,
becoming smooth to a light chop. A chance of showers and
thunderstorms.
.MONDAY...South to southwest winds 5 to 10 knots. Seas around
1 foot. Nearshore waters smooth to a light chop. A chance of
showers and thunderstorms.
.MONDAY NIGHT...South winds near 10 knots. Seas 1 to 2 feet.
Nearshore waters 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 near 10 knots. Seas
1 to 2 feet. Nearshore waters 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 winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. Showers likely with a chance of
thunderstorms.
.THURSDAY AND THURSDAY NIGHT...Southeast to south winds near 5
knots. Seas 1 foot or less. Nearshore waters smooth. Showers
likely with a chance of thunderstorms.
.FRIDAY AND FRIDAY NIGHT...Northeast to east winds near 5 knots.
Seas 1 foot or less. Nearshore waters smooth. A chance of showers
and thunderstorms.

$$

GMZ052>055-072>075-210845-
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-
438 PM EDT Sun Sep 20 2026

.TONIGHT...South winds near 5 knots, increasing to 5 to 10 knots
after midnight. Seas around 1 foot. Wave Detail: Southeast to
south 1 foot at 3 seconds. Showers likely with a chance of
thunderstorms.
.MONDAY...Southwest winds 5 to 10 knots. Seas around 1 foot. Wave
Detail: Southeast to south 1 foot at 3 seconds. A chance of
showers and thunderstorms.
.MONDAY 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. Wave Detail: East to southeast 2 feet
at 3 seconds. Showers likely with a chance of thunderstorms.
.TUESDAY...Southeast to south winds near 10 knots, decreasing to 5
to 10 knots. Seas around 2 feet, subsiding to 1 to 2 feet.
Showers likely with a chance of thunderstorms.
.TUESDAY NIGHT...Southeast to south winds near 10 knots. Seas
1 to 2 feet. Showers likely with a chance of thunderstorms.
.WEDNESDAY...Southeast to south winds 5 to 10 knots. Seas around
1 foot. Showers with a chance of thunderstorms.
.WEDNESDAY NIGHT...Southeast winds near 5 knots. Seas around
1 foot. Showers likely with a chance of thunderstorms.
.THURSDAY...Southeast to south winds near 5 knots. Seas around
1 foot. Showers likely with a chance of thunderstorms.
.THURSDAY NIGHT...Southeast to south winds near 5 knots. Seas
around 1 foot. A chance of showers and thunderstorms.
.FRIDAY...Northeast winds near 5 knots. Seas 1 foot or less. A
chance of showers and thunderstorms.
.FRIDAY NIGHT...East winds near 5 knots. Seas around 1 foot. A
chance of showers and thunderstorms.

$$

GMZ033-034-210845-
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-
438 PM EDT Sun Sep 20 2026

.TONIGHT...Northeast to east winds near 5 knots, becoming
southeast near 5 knots late this evening, then becoming south
after midnight. Seas 1 foot or less. Wave Detail: South 1 foot at
3 seconds. A chance of showers and thunderstorms.
.MONDAY...South to southwest winds near 5 knots. Seas 1 foot or
less. Wave Detail: South 1 foot at 3 seconds. A chance of showers
and thunderstorms.
.MONDAY NIGHT...Southeast to south winds 5 to 10 knots. Seas
around 1 foot. Wave Detail: Southeast to south 1 foot at
3 seconds. Showers likely with a chance of thunderstorms.
.TUESDAY...South winds 5 to 10 knots. Seas around 1 foot. Showers
likely with a chance of thunderstorms.
.TUESDAY NIGHT AND WEDNESDAY...Southeast to south winds 5 to 10
knots. Seas around 1 foot. Showers likely with a chance of
thunderstorms.
.WEDNESDAY NIGHT...Southeast winds near 5 knots. Seas 1 foot or
less. Showers likely with a chance of thunderstorms.
.THURSDAY...East to southeast winds near 5 knots. Seas 1 foot or
less. A chance of thunderstorms. A chance of showers.
.THURSDAY NIGHT...East winds near 5 knots. Seas 1 foot or less. A
chance of showers and thunderstorms.
.FRIDAY AND FRIDAY NIGHT...Northeast to east winds 5 to 10 knots.
Seas 1 to 2 feet. A chance of showers and thunderstorms.

$$

CLR