Coastal Waters Forecast
Issued by NWS Key West, FL

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852
FZUS52 KKEY 121427
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
1027 AM EDT Wed Mar 12 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.

GMZ005-122030-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
1027 AM EDT Wed Mar 12 2025

.SYNOPSIS...High pressure centered over the central Gulf will
slide eastward through the rest of the work week. Light to gentle
breezes will respond, veering from the north to northeast this
afternoon to the southeast by Thursday. A second, stronger high
will build in the western North Atlantic and interact with a
developing area of low pressure in the central United States,
supporting freshening southeasterly breezes for Friday night
through early Sunday. As the front approaches the Keys marine
zones late Sunday, breezes will once again briefly slacken.

The Approximate Shoreward Edge of the Gulf Stream as of March
8...

35 NM South of Dry Tortugas Light...on Loggerhead Key.
19 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
16 NM South of Sand Key Light...off Key West.
 8 NM South of Looe Key...off Big Pine Key.
 8 NM South of Sombrero Key Light...off Marathon.
 7 NM Southeast of Alligator Reef Light...off Islamorada.
 6 NM Southeast of Molasses Reef Light...off Key Largo.
 3 NM East of Carysfort Reef Light...off Ocean Reef.

Gulf Stream Information Courtesy of the National Weather Service in Key
West based on products from the Real Time Ocean Forecast System and
NASA SPoRT.

$$

GMZ031-122030-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
1027 AM EDT Wed Mar 12 2025

.THIS AFTERNOON...North to northeast winds 5 to 10 knots,
becoming east to southeast and decreasing to near 5 knots. Bay
waters smooth to a light chop, becoming smooth.
.TONIGHT...East to southeast winds 5 to 10 knots, increasing to
near 10 knots. Bay waters smooth to a light chop, becoming a light
chop.
.THURSDAY...Southeast winds near 10 knots, decreasing to 5 to 10
knots. Bay waters a light chop, becoming smooth to a light chop.
.THURSDAY NIGHT...East to southeast winds 5 to 10 knots. Bay
waters smooth to a light chop.
.FRIDAY...East to southeast winds 5 to 10 knots, increasing to
near 10 knots. Bay waters smooth to a light chop, becoming a light
chop.
.FRIDAY NIGHT...East to southeast winds near 10 knots, becoming
southeast and increasing to near 15 knots. Bay waters a light
chop, becoming a moderate chop.
.SATURDAY...Southeast winds 15 to 20 knots. Bay waters choppy.
.SATURDAY NIGHT...Southeast winds 15 to 20 knots. Bay waters
choppy. Isolated showers.
.SUNDAY...Southeast to south winds 15 to 20 knots, decreasing to
10 to 15 knots. Bay waters choppy, becoming a light to moderate
chop. Isolated showers.
.SUNDAY NIGHT...Southeast to south winds 10 to 15 knots,
becoming south and decreasing to 5 to 10 knots. Bay waters a
light to moderate chop, becoming smooth to a light chop. Isolated
showers.

$$

GMZ032-035-122030-
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-
1027 AM EDT Wed Mar 12 2025

.THIS AFTERNOON...North to northeast 5 to 10 knots, becoming east
to southeast. Seas 1 to 2 feet. Nearshore waters smooth to a
light chop.
.TONIGHT...East to southeast 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.
.THURSDAY...Southeast winds near 10 knots, decreasing to 5 to 10
knots. Seas 1 to 2 feet. Nearshore waters a light chop, becoming
smooth to a light chop.
.THURSDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
around 1 foot. Nearshore waters smooth to a light chop.
.FRIDAY...East to southeast winds 5 to 10 knots, increasing to
near 10 knots. Seas around 1 foot. Nearshore waters smooth to a
light chop, becoming a light chop.
.FRIDAY NIGHT...East to southeast winds near 10 knots, becoming
southeast and increasing to near 15 knots. Seas around 1 foot,
building to 1 to 2 feet. Nearshore waters a light chop, becoming
a moderate chop.
.SATURDAY...Southeast winds 15 to 20 knots. Seas 1 to 2 feet,
building to 2 to 3 feet. West of the Marquesas Keys, seas 2 to 3
feet, building to 3 to 4 feet, occasionally to 5 feet. Nearshore
waters choppy.
.SATURDAY NIGHT...Southeast winds 15 to 20 knots. Seas 2 to
3 feet, except 3 to 4 feet, occasionally to 5 feet west of the
Marquesas Keys. Nearshore waters choppy. Isolated showers.
.SUNDAY...Southeast to south winds 15 to 20 knots, becoming
southeast and decreasing to 10 to 15 knots. Seas 2 to 3 feet,
subsiding to 1 to 2 feet. West of the Marquesas Keys, seas 3 to 4
feet, occasionally to 5 feet, subsiding to 2 to 3 feet. Nearshore
waters choppy, becoming a light to moderate chop. Isolated
showers.
.SUNDAY NIGHT...Southeast winds 10 to 15 knots, becoming variable
and decreasing to 5 to 10 knots. Seas 1 to 2 feet. Nearshore
waters a light to moderate chop, becoming smooth to a light chop.
Isolated showers.

$$

GMZ042>044-122030-
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-
1027 AM EDT Wed Mar 12 2025

.THIS AFTERNOON...Northeast winds 5 to 10 knots, becoming east to
southeast. Seas 1 to 2 feet, except around 2 feet west of Cosgrove
Shoal Light. Nearshore waters smooth to a light chop.
.TONIGHT...East to southeast 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.
.THURSDAY...Southeast winds near 10 knots, decreasing to 5 to 10
knots. Seas 1 to 2 feet. Nearshore waters a light chop, becoming
smooth to a light chop.
.THURSDAY NIGHT...East to southeast winds 5 to 10 knots. Seas around
1 foot. Nearshore waters smooth to a light chop.
.FRIDAY...East to southeast winds 5 to 10 knots, increasing to
near 10 knots. Seas around 1 foot. Nearshore waters smooth to a
light chop, becoming a light chop.
.FRIDAY NIGHT...East to southeast winds near 10 knots, becoming
southeast and increasing to near 15 knots. Seas 1 to 2 feet,
building to 2 to 3 feet. Nearshore waters a light chop, becoming
a moderate chop.
.SATURDAY...Southeast winds 15 to 20 knots. Seas 3 to 4 feet,
occasionally to 5 feet. Nearshore waters choppy.
.SATURDAY NIGHT...Southeast winds 15 to 20 knots. Seas 3 to 5
feet, occasionally to 6 feet. Nearshore waters choppy. Isolated
showers.
.SUNDAY...Southeast to south winds 15 to 20 knots, becoming
southeast and decreasing to 10 to 15 knots. Seas 3 to 5 feet,
occasionally to 6 feet, subsiding to 2 to 4 feet, occasionally to
5 feet. Nearshore waters choppy, becoming a light to moderate
chop. Isolated showers.
.SUNDAY NIGHT...Southeast winds 10 to 15 knots, becoming variable
and decreasing to 5 to 10 knots. Seas 2 to 3 feet, subsiding to
around 2 feet. Nearshore waters a light to moderate chop,
becoming smooth to a light chop. Isolated showers.

$$

GMZ052>055-072>075-122030-
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-
1027 AM EDT Wed Mar 12 2025

.THIS AFTERNOON...North to northeast winds near 10 knots,
becoming east to southeast and decreasing to 5 to 10 knots. Seas 2
to 4 feet, occasionally to 5 feet, subsiding to 2 to 3 feet. Wave
Detail: West to northwest 3 feet at 8 seconds and northeast to
east 3 feet at 9 seconds.
.TONIGHT...East winds near 10 knots, becoming east to southeast
and increasing to 10 to 15 knots. Seas 2 to 3 feet. Wave Detail:
East 3 feet at 4 seconds and northwest 2 feet at 6 seconds.
.THURSDAY...Southeast winds 10 to 15 knots, decreasing to 5 to 10
knots. Seas 2 to 3 feet, subsiding to around 2 feet. Wave Detail:
East to southeast 3 feet at 4 seconds and west to northwest 1
foot at 6 seconds.
.THURSDAY NIGHT...East to southeast winds 5 to 10 knots. Seas
around 2 feet, subsiding to 1 to 2 feet.
.FRIDAY...East winds 5 to 10 knots, increasing to near 10 knots.
Seas 1 to 2 feet, building to around 2 feet.
.FRIDAY NIGHT...East to southeast winds 10 to 15 knots, becoming
southeast and increasing to 15 to 20 knots. Seas around 2 feet,
building to 2 to 4 feet, occasionally to 5 feet.
.SATURDAY...Southeast winds 15 to 20 knots. Seas 3 to 5 feet,
occasionally to 6 feet.
.SATURDAY NIGHT...Southeast winds 15 to 20 knots. Seas 4 to 6
feet, occasionally to 8 feet. Isolated showers.
.SUNDAY...Southeast to south winds 15 to 20 knots, becoming
southeast and decreasing to 10 to 15 knots. Seas 4 to 6 feet,
occasionally to 8 feet, subsiding to 3 to 4 feet, occasionally to
5 feet. Isolated showers.
.SUNDAY NIGHT...Southeast winds 10 to 15 knots, becoming east and
decreasing to near 10 knots. Seas 3 to 4 feet, occasionally to 5
feet, subsiding to 2 to 3 feet. Isolated showers.

$$

GMZ033-034-122030-
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-
1027 AM EDT Wed Mar 12 2025

.THIS AFTERNOON...Northeast winds 5 to 10 knots, becoming east.
Seas around 2 feet. Wave Detail: West to northwest 3 feet at 7
seconds.
.TONIGHT...East winds 5 to 10 knots, becoming east to southeast
and increasing to near 10 knots. Seas 1 to 2 feet. Wave Detail:
West to northwest 2 feet at 6 seconds and east to southeast 1 foot
at 2 seconds.
.THURSDAY...Southeast winds near 10 knots, becoming variable and
decreasing to near 5 knots. Seas 1 to 2 feet. Wave Detail:
Southeast 2 feet at 3 seconds and west to northwest 1 foot at 6
seconds.
.THURSDAY NIGHT...Variable winds near 5 knots, becoming northeast
to east. Seas around 1 foot.
.FRIDAY...East to southeast winds 5 to 10 knots. Seas around 1
foot.
.FRIDAY NIGHT...East to southeast winds 5 to 10 knots, becoming
southeast and increasing to near 15 knots. Seas around 1 foot,
building to 2 to 3 feet.
.SATURDAY...Southeast winds near 15 knots, increasing to 15 to 20
knots. Seas 2 to 3 feet, building to 3 to 4 feet, occasionally to
5 feet.
.SATURDAY NIGHT...Southeast winds 15 to 20 knots. Seas 3 to 4
feet, occasionally to 5 feet. Isolated showers.
.SUNDAY...Southeast winds 15 to 20 knots, decreasing to 10 to 15
knots. Seas 3 to 4 feet, occasionally to 5 feet, subsiding to 2 to
3 feet. Isolated showers.
.SUNDAY NIGHT...Southeast winds near 10 knots, becoming northeast
to east. Seas 2 to 3 feet. Isolated showers.

$$

MJV/BT