577
FZUS52 KKEY 200825
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
425 AM EDT Wed Aug 20 2025

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.

Wave Detail will include details about the period and direction
of origin for the highest energy waves. Long-period swells coming
from a different direction than the wind would be included in the
Wave Detail.

GMZ005-202030-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
425 AM EDT Wed Aug 20 2025

.SYNOPSIS...Hurricane Erin will continue to follow a mainly northerly
track today. The increasingly expansive circulation of Erin will
result in a transition from light to gentle variable breezes early
this morning to gentle to moderate northwest breezes by Tuesday
followed by moderate to fresh westerly breezes on Wednesday. A
slight swell from the north will lead to elevated seas in eastern
portions of the Florida Straits. As Hurricane Erin migrates
farther away toward the north and northeast, a weak subtropical
high pressure ridge will settle over Florida Keys coastal waters,
resulting in a lighter wind pattern Thursday through Saturday.

The Approximate Shoreward Edge of the Gulf Stream as of August
14...

45 NM South of Dry Tortugas Light...on Loggerhead Key.
34 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
41 NM South of Sand Key Light...off Key West.
24 NM South of Looe Key...off Big Pine Key.
18 NM Southeast of Sombrero Key Light...off Marathon.
 9 NM Southeast of Alligator Reef Light...off Islamorada.
 5 NM Southeast of Molasses Reef Light...off Key Largo.
 3 NM Southeast of Carysfort Reef Light...off Ocean Reef.

Gulf Stream Information Courtesy of the National Weather Service in
Key West based on products from NASA SPoRT.

$$

GMZ031-202030-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
425 AM EDT Wed Aug 20 2025

.TODAY...Variable winds 5 to 10 knots early, becoming west and
increasing to 10 to 15 knots. Bay waters smooth to a light chop,
becoming a light to moderate chop. Scattered showers and isolated
thunderstorms.
.TONIGHT...West winds 10 to 15 knots, decreasing to near 10 knots
late. Bay waters a light to moderate chop, becoming a light chop.
Scattered showers and isolated thunderstorms.
.THURSDAY...Southwest to west winds near 10 knots. Bay waters a
light chop. Scattered showers and isolated thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 10 knots,
decreasing to 5 to 10 knots. Bay waters a light chop, becoming smooth
to a light chop. Scattered showers and isolated thunderstorms.
.FRIDAY...Southwest to west winds 5 to 10 knots. Bay waters
smooth to a light chop. Scattered showers and isolated
thunderstorms.
.FRIDAY NIGHT...West winds 5 to 10 knots. Bay waters smooth to a
light chop. Isolated showers and thunderstorms.
.SATURDAY...Southwest to west winds 5 to 10 knots, decreasing to
near 5 knots. Bay waters smooth to a light chop, becoming smooth.
Scattered showers and isolated thunderstorms.
.SATURDAY NIGHT...Southwest to west winds near 5 knots. Bay
waters smooth. Isolated showers and thunderstorms.
.SUNDAY...Southwest winds near 5 knots, increasing to 5 to 10
knots. Bay waters smooth, becoming smooth to a light chop.
Isolated showers and thunderstorms.
.SUNDAY NIGHT...Southwest to west winds 5 to 10 knots, becoming
southwest. Bay waters smooth to a light chop. Isolated showers
and thunderstorms.

$$

GMZ032-035-202030-
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 AM EDT Wed Aug 20 2025

.TODAY...Variable winds 5 to 10 knots early, becoming west to
northwest and increasing to 10 to 15 knots. Seas 1 foot or less,
building to 1 to 2 feet. Nearshore waters smooth to a light chop,
becoming a light to moderate chop. Scattered showers and isolated
thunderstorms.
.TONIGHT...West winds 10 to 15 knots, decreasing to near 10 knots.
Seas 1 to 2 feet, subsiding to around 1 foot. Nearshore waters a
light to moderate chop, becoming a light chop. Scattered showers
and isolated thunderstorms.
.THURSDAY...Southwest to west winds near 10 knots. Seas around
1 foot. Nearshore waters a light chop. Scattered showers and
isolated thunderstorms.
.THURSDAY NIGHT...Southwest to west winds decreasing to 5 to 10
knots. Seas around 1 foot. Nearshore waters becoming smooth to a
light chop. Scattered showers and isolated thunderstorms.
.FRIDAY...Southwest to west winds 5 to 10 knots. Seas around 1
foot. Nearshore waters smooth to a light chop. Scattered showers
and isolated thunderstorms.
.FRIDAY NIGHT...Southwest to west winds 5 to 10 knots. Seas
1 foot or less. Nearshore waters smooth to a light chop. Isolated
showers and thunderstorms.
.SATURDAY...Southwest to west winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. Scattered showers and isolated
thunderstorms.
.SATURDAY NIGHT...West to northwest winds 5 to 10 knots, becoming
south to southwest. Seas 1 foot or less. Nearshore waters smooth
to a light chop. Isolated showers and thunderstorms.
.SUNDAY...Southwest to west winds 5 to 10 knots. Seas 1 foot or
less. Nearshore waters smooth to a light chop. Isolated showers
and thunderstorms.
.SUNDAY NIGHT...West to northwest winds 5 to 10 knots. Seas 1
foot or less. Nearshore waters smooth to a light chop, becoming
smooth. Isolated showers and thunderstorms.

$$

GMZ042-202030-
Hawk Channel from Ocean Reef to Craig Key out to the reef-
425 AM EDT Wed Aug 20 2025

.TODAY...Variable winds 5 to 10 knots early, becoming west and
increasing to 10 to 15 knots. Seas around 1 foot, building to 1
to 2 feet. Nearshore waters smooth to a light chop, becoming a
light to moderate chop. Scattered showers and isolated
thunderstorms.
.TONIGHT...West winds 10 to 15 knots. Seas 1 to 2 feet. Nearshore
waters a light to moderate chop. Scattered showers and isolated
thunderstorms.
.THURSDAY...Southwest to west 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. Scattered showers and
isolated thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 10 knots,
decreasing to 5 to 10 knots. Seas 1 to 2 feet, subsiding to around
1 foot. Nearshore waters a light chop, becoming smooth to a light
chop. Scattered showers and isolated thunderstorms.
.FRIDAY...Southwest to west winds 5 to 10 knots. Seas around
1 foot. Nearshore waters smooth to a light chop. Scattered
showers and isolated thunderstorms.
.FRIDAY NIGHT...West winds 5 to 10 knots. Seas around 1 foot.
Nearshore waters smooth to a light chop. Isolated showers and
thunderstorms.
.SATURDAY...Southwest to west winds near 5 knots. Seas around 1
foot. Nearshore waters smooth. Scattered showers and isolated
thunderstorms.
.SATURDAY NIGHT...Southwest to west winds near 5 knots. Seas
around 1 foot. Nearshore waters smooth. Isolated showers and
thunderstorms.
.SUNDAY AND SUNDAY NIGHT...Southwest winds 5 to 10 knots. Seas
around 1 foot. Nearshore waters smooth to a light chop. Isolated
showers and thunderstorms.

$$

GMZ043-044-202030-
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 AM EDT Wed Aug 20 2025

.TODAY...Variable winds 5 to 10 knots early, becoming west and
increasing to 10 to 15 knots. Seas around 1 foot. Nearshore waters
smooth to a light chop, becoming a light to moderate chop.
Scattered showers and isolated thunderstorms.
.TONIGHT...West winds 10 to 15 knots, decreasing to near 10
knots. Seas around 1 foot. Nearshore waters a light to moderate
chop, becoming a light chop. Scattered showers and isolated
thunderstorms.
.THURSDAY...Southwest to west winds near 10 knots, decreasing to 5
to 10 knots. Seas around 1 foot, subsiding to 1 foot or less.
Nearshore waters a light chop, becoming smooth to a light chop.
Scattered showers and isolated thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 5 knots. Seas
around 1 foot. Nearshore waters smooth. Scattered showers and
isolated thunderstorms.
.FRIDAY...Southwest to west winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. Scattered showers and isolated
thunderstorms.
.FRIDAY NIGHT...Southwest to west winds near 5 knots. Seas 1 foot
or less. Nearshore waters smooth. Isolated showers and
thunderstorms.
.SATURDAY...Southwest to west winds near 5 knots, becoming
variable. Seas 1 foot or less. Nearshore waters smooth. Scattered
showers and isolated thunderstorms.
.SATURDAY NIGHT...Variable winds near 5 knots, becoming southeast
to south. Seas 1 foot or less. Nearshore waters smooth. Isolated
showers and thunderstorms.
.SUNDAY...South winds near 5 knots, becoming southwest to west
Seas 1 foot or less. Nearshore waters smooth. Isolated showers and
thunderstorms.
.SUNDAY NIGHT...West to northwest winds near 5 knots. Seas 1 foot
or less. Nearshore waters smooth. Isolated showers and
thunderstorms.

$$

GMZ052-072-202030-
Straits of Florida from Ocean Reef to Craig Key out 20 NM-
Straits of Florida from Ocean Reef to Craig Key 20 to 60 NM out-
425 AM EDT Wed Aug 20 2025

.TODAY...West winds near 10 knots, increasing to 10 to 15 knots.
Seas around 2 feet, building to 2 to 3 feet due to northerly
swell. Wave Detail: West 2 feet at 3 seconds and north to
northeast 2 feet at 6 seconds. Scattered showers and isolated
thunderstorms.
.TONIGHT...West winds 10 to 15 knots. Seas 2 to 3 feet. Wave
Detail: West 2 feet at 4 seconds and north to northeast 1 foot at
5 seconds. Scattered showers and isolated thunderstorms.
.THURSDAY...Southwest to west winds 10 to 15 knots, decreasing to
near 10 knots. Seas 2 to 3 feet. Wave Detail: Southwest to west 2
feet at 3 seconds and north to northeast 2 feet at 12 seconds.
Scattered showers and isolated thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 10 knots,
decreasing to 5 to 10 knots. Seas 2 to 3 feet, subsiding to 1 to 2
feet. Isolated showers and thunderstorms.
.FRIDAY...Southwest to west winds 5 to 10 knots. Seas 1 to
2 feet. Isolated showers and thunderstorms.
.FRIDAY NIGHT...Southwest to west winds 5 to 10 knots. Seas 1 to
2 feet. Isolated showers and thunderstorms.
.SATURDAY AND SATURDAY NIGHT...Southwest to west winds near 5
knots. Seas 1 to 2 feet. Isolated showers and thunderstorms.
.SUNDAY...South to southwest winds near 5 knots. Seas 1 to
2 feet. Isolated showers and thunderstorms.
.SUNDAY NIGHT...South winds near 5 knots. Seas 1 to 2 feet.
Isolated showers and thunderstorms.

$$

GMZ053>055-073>075-202030-
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 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 AM EDT Wed Aug 20 2025

.TODAY...Variable winds 5 to 10 knots early, becoming west and
increasing to 10 to 15 knots. Seas 1 to 2 feet. Wave Detail:
Northwest 1 foot at 3 seconds and northeast to east 1 foot at
5 seconds. Scattered showers and isolated thunderstorms.
.TONIGHT...West winds 10 to 15 knots, decreasing to near 10
knots. Seas 1 to 2 feet. Wave Detail: Northwest 1 foot at 3
seconds and east 1 foot at 5 seconds. Scattered showers and
isolated thunderstorms.
.THURSDAY...Southwest to west winds near 10 knots, decreasing to 5
to 10 knots. Seas 1 to 2 feet. Wave Detail: Southwest to west 1
foot at 3 seconds and east 1 foot at 5 seconds. Scattered showers
and isolated thunderstorms.
.THURSDAY NIGHT...West winds decreasing to near 5 knots, becoming
south to southwest. Seas subsiding to around 1 foot. Isolated
showers and thunderstorms.
.FRIDAY...Southwest to west winds near 5 knots, becoming west to
northwest. Seas around 1 foot. Isolated showers and thunderstorms.
.FRIDAY NIGHT...West to northwest winds near 5 knots, becoming
variable. Seas around 1 foot. Isolated showers and thunderstorms.
.SATURDAY...Variable winds near 5 knots. Seas around 1 foot.
Isolated showers and thunderstorms.
.SATURDAY NIGHT...Variable winds near 5 knots, becoming east to
southeast. Seas around 1 foot. Isolated showers and thunderstorms.
.SUNDAY...East to southeast winds near 5 knots. Seas around
1 foot. Isolated showers and thunderstorms.
.SUNDAY NIGHT...Variable winds 5 to 10 knots. Seas around 1 foot.
Isolated showers and thunderstorms.

$$

GMZ033-034-202030-
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 AM EDT Wed Aug 20 2025

.TODAY...Variable winds 5 to 10 knots early, becoming west to
northwest and increasing to 10 to 15 knots late. Seas around 1
foot, building to 1 to 2 feet. Wave Detail: Northwest to north 1
foot at 3 seconds. Scattered showers and isolated thunderstorms.
.TONIGHT...West winds 10 to 15 knots, decreasing to near 10 knots.
Seas 1 to 2 feet. Wave Detail: Northwest 2 feet at 3 seconds.
Scattered showers and isolated thunderstorms.
.THURSDAY...Southwest to west winds near 10 knots, decreasing to
5 to 10 knots. Seas 1 to 2 feet, subsiding to around 1 foot. Wave
Detail: West 1 foot at 3 seconds. Scattered showers and isolated
thunderstorms.
.THURSDAY NIGHT...Southwest to west winds 5 to 10 knots. Seas
around 1 foot. Isolated showers and thunderstorms.
.FRIDAY...Southwest to west winds 5 to 10 knots. Seas around
1 foot. Scattered showers and isolated thunderstorms.
.FRIDAY NIGHT...Southwest to west winds 5 to 10 knots. Seas
around 1 foot. Isolated showers and thunderstorms.
.SATURDAY...Southwest to west winds near 5 knots, becoming west to
northwest. Seas around 1 foot. Scattered showers and isolated
thunderstorms.
.SATURDAY NIGHT...West to northwest winds near 5 knots, becoming
southwest to west. Seas around 1 foot. Isolated showers and
thunderstorms.
.SUNDAY...Southwest to west winds near 5 knots. Seas around 1
foot. Isolated showers and thunderstorms.
.SUNDAY NIGHT...West to northwest winds near 5 knots. Seas around
1 foot. Isolated showers and thunderstorms.

$$

DP