Coastal Waters Forecast
Issued by NWS Key West, FL

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961
FZUS52 KKEY 282026
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
426 PM EDT Thu Aug 28 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.

GMZ005-290830-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
426 PM EDT Thu Aug 28 2025

.SYNOPSIS...An early season Canadian high pressure system will
continue to traverse the eastern United States over the next few
days. As it does, it will enhance the pressure gradient slightly
across the Florida Keys marine zones. As a result, expect light to
gentle, except gentle to moderate breezes across the Straits of
Florida through tonight. As the high moves into the Atlantic late
week and over the weekend, breezes will slacken. Increased
moisture will support higher shower and thunderstorm coverage
through early next week.

The Approximate Shoreward Edge of the Gulf Stream as of August 21...

20 NM South of Dry Tortugas Light...on Loggerhead Key.
 9 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
 9 NM South of Sand Key Light...off Key West.
13 NM South of Looe Key...off Big Pine Key.
17 NM Southeast of Sombrero Key Light...off Marathon.
17 NM Southeast of Alligator Reef Light...off Islamorada.
13 NM Southeast of Molasses Reef Light...off Key Largo.
 5 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.

$$

GMZ031-290830-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
426 PM EDT Thu Aug 28 2025

.TONIGHT...East to southeast winds near 10 knots, decreasing to 5
to 10 knots. Bay waters a light chop, becoming smooth to a light
chop. Scattered showers and thunderstorms.
.FRIDAY...East to southeast winds near 5 knots. Bay waters
smooth. Scattered showers and thunderstorms.
.FRIDAY NIGHT...Variable winds near 5 knots, becoming southeast
to south and increasing to 5 to 10 knots after midnight. Bay
waters smooth, becoming smooth to a light chop. Scattered showers
and thunderstorms.
.SATURDAY...Southwest winds decreasing to near 5 knots. Bay
waters becoming smooth. Scattered showers and thunderstorms.
.SATURDAY NIGHT...Variable winds near 5 knots. Bay waters smooth.
Scattered showers and thunderstorms.
.SUNDAY...Southwest to west winds 5 to 10 knots. Bay waters
smooth to a light chop. Scattered showers and thunderstorms.
.SUNDAY NIGHT...West to northwest winds near 10 knots. Bay waters
a light chop. Scattered showers and thunderstorms.
.MONDAY...Southwest to west winds near 10 knots, increasing to 10
to 15 knots. Bay waters a light chop, becoming a light to
moderate chop. Scattered showers and thunderstorms.
.MONDAY NIGHT THROUGH TUESDAY NIGHT...West winds 10 to 15 knots.
Bay waters a light to moderate chop. Scattered showers and
thunderstorms.

$$

GMZ032-035-290830-
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-
426 PM EDT Thu Aug 28 2025

.TONIGHT...East to southeast winds near 10 knots. Seas around 1
foot, except 1 to 2 feet west of the Marquesas Keys. Nearshore
waters a light chop. Scattered showers and thunderstorms.
.FRIDAY...East winds 5 to 10 knots, decreasing to near 5 knots.
Seas 1 foot or less, except around 1 foot west of the Marquesas
Keys. Nearshore waters smooth to a light chop, becoming smooth.
Scattered showers and thunderstorms.
.FRIDAY NIGHT...Variable winds near 5 knots, becoming southeast to
south and increasing to 5 to 10 knots after midnight. Seas 1 foot
or less, except around 1 foot west of the Marquesas Keys.
Nearshore waters smooth, becoming smooth to a light chop.
Scattered showers and thunderstorms.
.SATURDAY...South to southwest winds near 5 knots, becoming west.
Seas 1 foot or less. Nearshore waters smooth. Scattered showers
and thunderstorms.
.SATURDAY NIGHT...Variable winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. Scattered showers and
thunderstorms.
.SUNDAY...Southwest to west winds 5 to 10 knots, becoming west to
northwest. Seas 1 foot or less. Nearshore waters smooth to a
light chop. Scattered showers and thunderstorms.
.SUNDAY NIGHT...West to northwest winds 5 to 10 knots. Seas
around 1 foot. Nearshore waters smooth to a light chop. Scattered
showers and thunderstorms.
.MONDAY...West winds near 10 knots. Seas around 1 foot. Nearshore
waters a light chop. Scattered showers and thunderstorms.
.MONDAY NIGHT THROUGH TUESDAY NIGHT...West winds 10 to 15 knots.
Seas 1 to 2 feet. Nearshore waters a light to moderate chop.
Scattered showers and thunderstorms.

$$

GMZ042>044-290830-
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-
426 PM EDT Thu Aug 28 2025

.TONIGHT...East to southeast winds near 10 knots. Seas around 2
feet. Nearshore waters a light chop. Scattered showers and
thunderstorms.
.FRIDAY...East to southeast winds 5 to 10 knots, decreasing to
near 5 knots. Seas 1 to 2 feet, subsiding to around 1 foot.
Nearshore waters smooth to a light chop, becoming smooth.
Scattered showers and thunderstorms.
.FRIDAY NIGHT...Variable winds near 5 knots, becoming southeast to
south and increasing to near 10 knots after midnight. Seas around
1 foot, building to 1 to 2 feet. Nearshore waters smooth,
becoming a light chop. Scattered showers and thunderstorms.
.SATURDAY...Southwest winds decreasing to near 5 knots. Seas
subsiding to 1 foot or less. Nearshore waters becoming smooth.
Scattered showers and thunderstorms.
.SATURDAY NIGHT...Variable winds near 5 knots. Seas 1 foot or
less. Nearshore waters smooth. Scattered showers and
thunderstorms.
.SUNDAY...Southwest to west winds 5 to 10 knots, becoming west to
northwest. Seas around 1 foot. Nearshore waters smooth to a light
chop. Scattered showers and thunderstorms.
.SUNDAY NIGHT...West to northwest winds 5 to 10 knots. Seas
around 1 foot. Nearshore waters smooth to a light chop. Scattered
showers and thunderstorms.
.MONDAY...West winds near 10 knots. Seas 1 to 2 feet. Nearshore
waters a light chop. Scattered showers and thunderstorms.
.MONDAY NIGHT THROUGH TUESDAY NIGHT...West winds 10 to 15 knots.
Seas 1 to 2 feet. Nearshore waters a light to moderate chop.
Scattered showers and thunderstorms.

$$

GMZ052>055-072>075-290830-
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-
426 PM EDT Thu Aug 28 2025

.TONIGHT...East to southeast winds 10 to 15 knots, decreasing to
near 10 knots. Seas 2 to 3 feet, subsiding to around 2 feet. Wave
Detail: East 2 feet at 4 seconds. Scattered showers and
thunderstorms.
.FRIDAY...East to southeast winds 5 to 10 knots, becoming east and
decreasing to near 5 knots. Seas around 2 feet, subsiding to 1 to
2 feet. Wave Detail: East 2 feet at 4 seconds. Scattered showers
and thunderstorms.
.FRIDAY NIGHT...Northeast to east winds 5 to 10 knots, becoming
southeast to south and increasing to near 10 knots after
midnight. Seas around 1 foot, building to 1 to 2 feet. Wave
Detail: East 1 foot at 4 seconds. Scattered showers and
thunderstorms.
.SATURDAY...South to southwest winds 5 to 10 knots, becoming west.
Seas 1 to 2 feet. Scattered showers and thunderstorms.
.SATURDAY NIGHT...Variable winds near 5 knots. Seas 1 foot or
less. Scattered showers and thunderstorms.
.SUNDAY...Southwest winds 5 to 10 knots, becoming west to
northwest in the afternoon. Seas 1 to 2 feet. Scattered showers
and thunderstorms.
.SUNDAY NIGHT...West to northwest winds 5 to 10 knots. Seas
1 to 2 feet. Scattered showers and thunderstorms.
.MONDAY...West winds near 10 knots. Seas 1 to 2 feet. Scattered
showers and thunderstorms.
.MONDAY NIGHT THROUGH TUESDAY NIGHT...West winds 10 to 15 knots.
Seas around 2 feet. Scattered showers and thunderstorms.

$$

GMZ033-034-290830-
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-
426 PM EDT Thu Aug 28 2025

.TONIGHT...East winds 5 to 10 knots, becoming east to southeast.
Seas around 1 foot. Wave Detail: East 1 foot at 2 seconds and
northwest to north 1 foot at 4 seconds. Scattered showers and
thunderstorms.
.FRIDAY...East winds near 5 knots. Seas 1 foot or less. Wave
Detail: East to southeast 1 foot at 3 seconds. Scattered showers
and thunderstorms.
.FRIDAY NIGHT...Northeast winds 5 to 10 knots, becoming southeast
after midnight. Seas around 1 foot. Scattered showers and
thunderstorms.
.SATURDAY...Southwest to west winds near 5 knots. Seas 1 foot or
less. Scattered showers and thunderstorms.
.SATURDAY NIGHT...Variable winds near 5 knots. Seas 1 foot or
less. Scattered showers and thunderstorms.
.SUNDAY...Southwest to west winds 5 to 10 knots, becoming west to
northwest. Seas around 1 foot. Scattered showers and
thunderstorms.
.SUNDAY NIGHT...West to northwest winds 5 to 10 knots. Seas
around 1 foot. Scattered showers and thunderstorms.
.MONDAY...West winds near 10 knots. Seas 1 to 2 feet. Scattered
showers and thunderstorms.
.MONDAY NIGHT...West to northwest winds 10 to 15 knots. Seas
around 2 feet. Scattered showers and thunderstorms.
.TUESDAY...West winds near 10 knots. Seas 1 to 2 feet. Numerous
showers and scattered thunderstorms.
.TUESDAY NIGHT...West winds 10 to 15 knots. Seas 2 to 3 feet.
Scattered showers and thunderstorms.

$$

DP/MC