255
FZUS52 KKEY 092018
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
418 PM EDT Thu Oct 9 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.

GMZ005-100830-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
418 PM EDT Thu Oct 9 2025

.SYNOPSIS...An inverted trough will remain in the vicinity of the
Florida Keys marine zones over the next couple of days,
supporting bouts of elevated rain and thunder chances. The
proximity of the trough to the Keys will also maintain generally
gentle northeast to east breezes. A developing area of low
pressure off the coast of the Carolinas will drive an early season
cold front towards the Keys over the weekend, backing winds to
the north to northeast. Northerly swells will be possible in our
eastern marine zones late in the weekend into early next week due
to the influence of the low pressure system.

The Approximate Shoreward Edge of the Gulf Stream as of October
08...

46 NM South of Dry Tortugas Light...on Loggerhead Key.
27 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
21 NM South of Sand Key Light...off Key West.
30 NM South of Looe Key...off Big Pine Key.
14 NM Southeast of Sombrero Key Light...off Marathon.
 8 NM Southeast of Alligator Reef Light...off Islamorada.
 7 NM Southeast of Molasses Reef Light...off Key Largo.
 6 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.

$$

GMZ031-100830-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
418 PM EDT Thu Oct 9 2025

.TONIGHT...East to southeast winds near 10 knots, becoming
decreasing to 5 to 10 knots. Bay waters a light chop, becoming
smooth to a light chop. Widespread showers and scattered
thunderstorms.
.FRIDAY...East to southeast winds near 5 knots, becoming variable.
Bay waters smooth. Widespread showers and isolated thunderstorms.
.FRIDAY NIGHT...Variable winds near 5 knots. Bay waters smooth.
Numerous showers and isolated thunderstorms.
.SATURDAY...Variable winds near 5 knots, becoming northwest. Bay
waters smooth. Scattered showers and isolated thunderstorms.
.SATURDAY NIGHT...Northwest to north winds increasing to 5 to 10
knots. Bay waters becoming smooth to a light chop. Isolated
showers and thunderstorms.
.SUNDAY...North winds 5 to 10 knots. Bay waters smooth to a light
chop. Isolated showers.
.SUNDAY NIGHT...Northeast winds 5 to 10 knots. Bay waters smooth
to a light chop. Isolated showers.
.MONDAY...Northeast to east winds 5 to 10 knots. Bay waters
smooth to a light chop. Isolated showers.
.MONDAY NIGHT...Northeast to east winds near 10 knots. Bay waters
a light chop. Isolated showers.
.TUESDAY...Northeast winds near 10 knots. Bay waters a light
chop. Isolated showers.
.TUESDAY NIGHT...North to northeast winds 5 to 10 knots. Bay
waters smooth to a light chop. Isolated showers.

$$

GMZ032-035-100830-
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-
418 PM EDT Thu Oct 9 2025

.TONIGHT...East winds near 10 knots, becoming east to southeast
and decreasing to 5 to 10 knots. Seas 1 to 2 feet, subsiding to
around 1 foot. Nearshore waters smooth to a light chop. Widespread
showers and scattered thunderstorms.
.FRIDAY...East to southeast winds 5 to 10 knots, becoming
northeast to east and decreasing to near 5 knots. Seas around 1
foot, except building to 1 to 2 feet west of the Marquesas Keys
due to a northerly swell. Nearshore waters smooth to a light
chop, becoming smooth. Widespread showers and scattered
thunderstorms.
.FRIDAY NIGHT...North to northeast winds near 5 knots, becoming
northwest to north. Seas around 1 foot, except around 2 feet west
of the Marquesas Keys. Nearshore waters smooth. Numerous showers
and isolated thunderstorms.
.SATURDAY...Northwest to north winds 5 to 10 knots, increasing to
near 10 knots. Seas 1 to 2 feet. Nearshore waters smooth to a
light chop, becoming a light chop. Scattered showers and isolated
thunderstorms.
.SATURDAY NIGHT...North 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. Isolated
showers and thunderstorms.
.SUNDAY...North winds 5 to 10 knots. Seas around 1 foot.
Nearshore waters smooth to a light chop. Isolated showers.
.SUNDAY NIGHT...North winds 5 to 10 knots. Seas around 1 foot.
Nearshore waters smooth to a light chop. Isolated showers.
.MONDAY AND MONDAY NIGHT...Northeast to east winds 5 to 10 knots.
Seas around 1 foot. Nearshore waters smooth to a light chop.
Isolated showers.
.TUESDAY...Northeast winds near 10 knots. Seas around 1 foot.
Nearshore waters a light chop. Isolated showers.
.TUESDAY NIGHT...North to northeast winds 5 to 10 knots. Seas
1 to 2 feet. Nearshore waters smooth to a light chop. Isolated
showers.

$$

GMZ042>044-100830-
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-
418 PM EDT Thu Oct 9 2025

.TONIGHT...East winds near 10 knots, becoming east to southeast
and 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. Widespread showers and scattered thunderstorms.
.FRIDAY...East to southeast winds near 5 knots, becoming variable.
Seas around 1 foot. Nearshore waters smooth. Widespread showers
and scattered thunderstorms.
.FRIDAY NIGHT...Variable winds near 5 knots, becoming southeast
after midnight. Seas around 1 foot. Nearshore waters smooth.
Numerous showers and isolated thunderstorms.
.SATURDAY...Variable winds increasing to 5 to 10 knots, becoming
northwest to north. Seas around 1 foot, except building to 2 to 3
feet west of Cosgrove Shoal Light due to a northerly swell.
Nearshore waters smooth to a light chop. Scattered showers and
isolated thunderstorms.
.SATURDAY NIGHT...Northwest to north winds 5 to 10 knots. Seas
1 to 2 feet. Nearshore waters smooth to a light chop. Scattered
showers and isolated thunderstorms.
.SUNDAY...North to northeast winds 5 to 10 knots. Seas 1 to 2
feet. Nearshore waters smooth to a light chop. Isolated showers.
.SUNDAY NIGHT THROUGH MONDAY NIGHT...Northeast to east winds near
10 knots. Seas 1 to 2 feet. Nearshore waters a light chop.
Isolated showers.
.TUESDAY...Northeast winds near 10 knots. Seas 1 to 2 feet.
Nearshore waters a light chop. Isolated showers.
.TUESDAY NIGHT...Northeast winds near 10 knots. Seas 1 to 2 feet.
Nearshore waters a light chop. Isolated showers.

$$

GMZ052>055-072>075-100830-
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-
418 PM EDT Thu Oct 9 2025

.TONIGHT...East to southeast winds near 10 knots, decreasing to 5
to 10 knots. Seas 1 to 2 feet. Wave Detail: East 2 feet at 4
seconds. Widespread showers and scattered thunderstorms.
.FRIDAY...Southeast to south winds 5 to 10 knots. Seas 1 to
2 feet. Wave Detail: East 1 foot at 4 seconds. Widespread showers
and scattered thunderstorms.
.FRIDAY NIGHT...South to southwest winds 5 to 10 knots. Seas 1 to
2 feet, building to 2 to 3 feet due to northerly swell. Wave
Detail: Northwest 2 feet at 7 seconds and east 1 foot at 4
seconds. Numerous showers and isolated thunderstorms.
.SATURDAY...West to northwest winds 5 to 10 knots. Seas 2 to
3 feet. Scattered showers and isolated thunderstorms.
.SATURDAY NIGHT...Northwest to north winds 5 to 10 knots. Seas
2 to 3 feet. Scattered showers and isolated thunderstorms.
.SUNDAY...North to northeast winds 5 to 10 knots. Seas 2 to
3 feet. Isolated showers.
.SUNDAY NIGHT THROUGH MONDAY NIGHT...Northeast to east winds near
10 knots. Seas 2 to 3 feet. Isolated showers.
.TUESDAY...Northeast winds 10 to 15 knots. Seas 2 to 4 feet,
occasionally to 5 feet. Isolated showers.
.TUESDAY NIGHT...Northeast winds near 10 knots. Seas 2 to 4 feet,
occasionally to 5 feet. Isolated showers.

$$

GMZ033-034-100830-
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-
418 PM EDT Thu Oct 9 2025

.TONIGHT...Northeast to east winds 10 to 15 knots, decreasing to
near 10 knots. Seas 2 to 3 feet, subsiding to 1 to 2 feet. Wave
Detail: Northeast to east 2 feet at 4 seconds. Numerous showers
and scattered thunderstorms.
.FRIDAY...Northeast to east winds near 10 knots, decreasing to 5
to 10 knots. Seas building to 2 to 3 feet due to a northerly
swell. Wave Detail: North to northeast 2 feet at 5 seconds.
Numerous showers and scattered thunderstorms.
.FRIDAY NIGHT...Northeast winds 5 to 10 knots. Seas 2 to 3 feet.
Wave Detail: Northwest to north 3 feet at 7 seconds. Numerous
showers and isolated thunderstorms.
.SATURDAY...North to northeast winds near 10 knots. Seas building
to 2 to 4 feet, occasionally to 5 feet due to a northerly swell.
Scattered showers and isolated thunderstorms.
.SATURDAY NIGHT...North winds near 10 knots. Seas 2 to 3 feet.
Isolated showers and thunderstorms.
.SUNDAY...North to northeast winds 5 to 10 knots. Seas 2 to
3 feet. Isolated showers.
.SUNDAY NIGHT...Northeast to east winds near 10 knots. Seas 1 to
2 feet. Isolated showers.
.MONDAY...Northeast to east winds 5 to 10 knots. Seas 1 to
2 feet. Isolated showers.
.MONDAY NIGHT...Northeast to east winds near 10 knots. Seas 1 to
2 feet. Isolated showers.
.TUESDAY...Northeast winds near 10 knots. Seas 1 to 2 feet.
Isolated showers.
.TUESDAY NIGHT...North to northeast winds 10 to 15 knots. Seas
1 to 2 feet. Isolated showers.

$$