419
FZUS52 KKEY 020819
CWFKEY

Coastal Waters Forecast for the Florida Keys
National Weather Service Key West FL
419 AM EDT Tue Sep 2 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.

GMZ005-022030-
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas
419 AM EDT Tue Sep 2 2025

.SYNOPSIS...A broad surface low situated along a stationary
front sits off the Florida East coast, east of Lake Okeechobee
with the Keys lying to the south of this boundary. This is
maintaining west to northwest winds across the Florida Keys
coastal waters this morning. The low and front will remain rooted
in place through the next few days with undulating winds varying
between northwest and southwest. Localized wind surges will be
possible off the Upper Keys each afternoon starting today and
going through Thursday. In addition, abundant moisture will
promote above normal rain and thunder chances through the end of
the week.


The Approximate Shoreward Edge of the Gulf Stream as of September 1...

41 NM South of Dry Tortugas Light...on Loggerhead Key.
30 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
 9 NM South of Sand Key Light...off Key West.
 8 NM South of Looe Key...off Big Pine Key.
 7 NM Southeast of Sombrero Key Light...off Marathon.
 6 NM Southeast of Alligator Reef Light...off Islamorada.
 4 NM Southeast of Molasses Reef Light...off Key Largo.
 4 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.

$$

GMZ031-022030-
Florida Bay including Barnes Sound, Blackwater Sound, and
Buttonwood Sound-
419 AM EDT Tue Sep 2 2025

.TODAY...West to northwest winds near 10 knots, increasing to
near 15 knots. Bay waters a light chop, becoming to a moderate
chop. Bay waters rough and winds higher in and around numerous
showers and scattered thunderstorms.
.TONIGHT...West to northwest winds 10 to 15 knots, decreasing to
near 10 knots. Bay waters a light to moderate chop, becoming a
light chop. Numerous showers and scattered thunderstorms.
.WEDNESDAY...West winds near 10 knots, becoming southwest to west
10 to 15 knots. Bay waters a light chop, becoming a light to
moderate chop. Widespread showers and scattered thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds 10 to 15 knots. Bay
waters a light to moderate chop. Numerous showers and scattered
thunderstorms.
.THURSDAY...Southwest to west winds increasing to near 15 knots.
Bay waters becoming a moderate chop. Widespread showers and
scattered thunderstorms.
.THURSDAY NIGHT...Southwest to west winds decreasing to 10 to 15
knots. Bay waters becoming a light to moderate chop. Widespread
showers and scattered thunderstorms.
.FRIDAY...Southwest to west winds 10 to 15 knots. Bay waters a
light to moderate chop. Widespread showers and scattered
thunderstorms.
.FRIDAY NIGHT...Southwest winds near 10 knots. Bay waters a light
chop. Scattered showers and thunderstorms.
.SATURDAY...South to southwest winds decreasing to 5 to 10 knots.
Bay waters becoming smooth to a light chop. Scattered showers and
thunderstorms.
.SATURDAY NIGHT...South to southwest winds 5 to 10 knots,
becoming east to southeast. Bay waters smooth to a light chop.
Scattered showers and thunderstorms.

$$

GMZ032-035-022030-
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-
419 AM EDT Tue Sep 2 2025

.TODAY...West to northwest winds near 10 knots, increasing to 10
to 15 knots. Seas 1 to 2 feet. Nearshore waters a light chop,
becoming a light to moderate chop. Winds and seas higher in and
around numerous showers and scattered thunderstorms.
.TONIGHT...West to northwest 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.
Numerous showers and scattered thunderstorms.
.WEDNESDAY...West winds near 10 knots, increasing to 10 to 15
knots. Seas around 1 foot, except building to 1 to 2 feet west of
the Marquesas Keys. Nearshore waters a light chop, becoming a
light to moderate chop. Widespread showers and scattered
thunderstorms.
.WEDNESDAY NIGHT...West winds 10 to 15 knots. Seas 1 to 2 feet.
Nearshore waters a light to moderate chop. Widespread showers and
scattered thunderstorms.
.THURSDAY...Southwest to west winds 10 to 15 knots. Seas 1 to
2 feet, except building to 2 to 3 feet west of the Marquesas Keys.
Nearshore waters a light to moderate chop. Widespread showers and
scattered thunderstorms.
.THURSDAY NIGHT...Southwest to west winds 10 to 15 knots,
decreasing to near 10 knots. Seas 1 to 2 feet. West of the
Marquesas Keys, seas 2 to 3 feet, subsiding to around 2 feet.
Nearshore waters a light to moderate chop, becoming a light chop.
Widespread showers and scattered thunderstorms.
.FRIDAY...Southwest to west winds near 10 knots, increasing to
10 to 15 knots. Seas 1 to 2 feet. Nearshore waters a light chop,
becoming to a light to moderate chop. Widespread showers and
scattered thunderstorms.
.FRIDAY NIGHT...Southwest winds decreasing to near 10 knots. Seas
1 to 2 feet. Nearshore waters becoming a light chop. Scattered
showers and thunderstorms.
.SATURDAY...Southwest winds decreasing to 5 to 10 knots. Seas
subsiding to around 1 foot. Nearshore waters becoming smooth to a
light chop. Scattered showers and thunderstorms.
.SATURDAY NIGHT...South to southwest winds 5 to 10 knots,
becoming east to southeast. Seas 1 foot or less. Nearshore waters
smooth to a light chop. Scattered showers and thunderstorms.

$$

GMZ042-022030-
Hawk Channel from Ocean Reef to Craig Key out to the reef-
419 AM EDT Tue Sep 2 2025

...SMALL CRAFT SHOULD EXERCISE CAUTION FOR INCREASING WINDS...

.TODAY...West to northwest winds near 10 knots, briefly
increasing to 15 to 20 knots in the afternoon. Seas 1 to 2 feet,
building to around 2 feet. Nearshore waters a light chop,
becoming choppy. Winds and seas higher in and around numerous
showers and scattered thunderstorms.
.TONIGHT...West to northwest winds near 15 knots, decreasing to
10 to 15 knots. Seas subsiding to 1 to 2 feet. Nearshore waters a
moderate chop, becoming a light to moderate chop. Numerous
showers and scattered thunderstorms.
.WEDNESDAY...West winds near 10 knots, becoming southwest to west
10 to 15 knots. Seas 1 to 2 feet. Nearshore waters a light chop,
becoming a light to moderate chop. Widespread showers and
scattered thunderstorms.
.WEDNESDAY NIGHT...West winds 10 to 15 knots. Seas 1 to 2 feet.
Nearshore waters a light to moderate chop. Widespread showers and
scattered thunderstorms.
.THURSDAY...Southwest to west winds 10 to 15 knots, increasing to
near 15 knots. Seas 1 to 2 feet, building to around 2 feet.
Nearshore waters a light to moderate chop, becoming a moderate
chop. Widespread showers and scattered thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 15 knots,
decreasing to 10 to 15 knots. Seas subsiding to 1 to 2 feet.
Nearshore waters a moderate chop, becoming a light to moderate
chop. Widespread showers and scattered thunderstorms.
.FRIDAY...Southwest to west winds 10 to 15 knots. Seas 1 to
2 feet. Nearshore waters a light to moderate chop. Widespread
showers and scattered thunderstorms.
.FRIDAY NIGHT...Southwest winds decreasing to near 10 knots. Seas
1 to 2 feet. Nearshore waters becoming a light chop. Scattered
showers and thunderstorms.
.SATURDAY...Southwest winds decreasing to 5 to 10 knots. Seas
around 1 foot. Nearshore waters becoming smooth to a light chop.
Scattered showers and thunderstorms.
.SATURDAY NIGHT...South to southwest winds 5 to 10 knots,
becoming east to southeast. Seas around 1 foot. Nearshore waters
smooth to a light chop. Scattered showers and thunderstorms.

$$

GMZ043-044-022030-
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-
419 AM EDT Tue Sep 2 2025

.TODAY...West to northwest winds near 10 knots, increasing to 10
to 15 knots. Seas 1 to 2 feet. Nearshore waters a light chop,
becoming a light to moderate chop. Winds and seas higher in and
around numerous showers and scattered thunderstorms.
.TONIGHT...West to northwest 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. Numerous showers and
scattered thunderstorms.
.WEDNESDAY...West winds near 10 knots, becoming southwest to west
10 to 15 knots. Seas around 1 foot. Nearshore waters a light
chop, becoming a light to moderate chop. Widespread showers and
scattered thunderstorms.
.WEDNESDAY NIGHT...West winds 10 to 15 knots. Seas 1 to 2 feet.
Nearshore waters a light to moderate chop. Widespread showers and
scattered thunderstorms.
.THURSDAY...Southwest to west winds 10 to 15 knots, increasing to
near 15 knots. Seas 1 to 2 feet, except building to 2 to 3 feet
west of Cosgrove Shoal Light. Nearshore waters a light to
moderate chop, becoming a moderate chop. Widespread showers and
scattered thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 15 knots,
decreasing to 10 to 15 knots. Seas around 2 feet. West of
Cosgrove Shoal Light, seas 2 to 3 feet, subsiding to around 2
feet. Nearshore waters a moderate chop, becoming a light to
moderate chop. Widespread showers and scattered thunderstorms.
.FRIDAY...Southwest to west winds 10 to 15 knots. Seas around 2
feet. Nearshore waters a light to moderate chop. Widespread
showers and scattered thunderstorms.
.FRIDAY NIGHT...Southwest winds decreasing to near 10 knots. Seas
1 to 2 feet. Nearshore waters becoming a light chop. Scattered
showers and thunderstorms.
.SATURDAY...Southwest winds decreasing to 5 to 10 knots. Seas
around 1 foot. Nearshore waters becoming smooth to a light chop.
Scattered showers and thunderstorms.
.SATURDAY NIGHT...South to southwest winds 5 to 10 knots,
becoming east to southeast. Seas around 1 foot. Nearshore waters
smooth to a light chop. Scattered showers and thunderstorms.

$$

GMZ052-072-022030-
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-
419 AM EDT Tue Sep 2 2025

...SMALL CRAFT SHOULD EXERCISE CAUTION FOR INCREASING WINDS...

.TODAY...West to northwest winds 10 to 15 knots, becoming
southwest to west and briefly increasing to 15 to 20 knots in the
afternoon. Seas 1 to 2 feet, building to 2 to 3 feet. Wave
Detail: Southwest to west 2 feet at 3 seconds and north to
northeast 1 foot at 8 seconds. Winds and seas higher in and around
numerous showers and scattered thunderstorms.
.TONIGHT...Southwest to west winds 15 to 20 knots early, becoming
west to northwest 10 to 15 knots. Seas 3 to 4 feet, subsiding to
2 to 3 feet. Wave Detail: Southwest to west 2 feet at 3 seconds
and north to northeast 1 foot at 8 seconds. Numerous showers and
scattered thunderstorms.
.WEDNESDAY...West to northwest winds 10 to 15 knots, becoming
southwest to west. Seas subsiding to around 2 feet. Wave Detail:
Southwest to west 2 feet at 3 seconds and north to northeast 1
foot at 8 seconds. Widespread showers and scattered thunderstorms.
.WEDNESDAY NIGHT...Southwest to west winds 10 to 15 knots. Seas
around 2 feet. Widespread showers and scattered thunderstorms.
.THURSDAY...Southwest to west winds near 15 knots. Seas 2 to 3
feet. Widespread showers and scattered thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 15 knots,
decreasing to 10 to 15 knots. Seas subsiding to around 2 feet.
Widespread showers and scattered thunderstorms.
.FRIDAY...Southwest winds 10 to 15 knots. Seas around 2 feet.
Widespread showers and scattered thunderstorms.
.FRIDAY NIGHT...South to southwest winds decreasing to near 10
knots. Seas subsiding to 1 to 2 feet. Scattered showers and
thunderstorms.
.SATURDAY...South to southwest winds decreasing to 5 to 10 knots.
Seas subsiding to around 1 foot. Scattered showers and
thunderstorms.
.SATURDAY NIGHT...Southeast winds 5 to 10 knots. Seas around 1
foot. Numerous showers and scattered thunderstorms.

$$

GMZ053>055-073>075-022030-
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-
419 AM EDT Tue Sep 2 2025

.TODAY...West to northwest winds 10 to 15 knots, increasing to
near 15 knots in the afternoon. Seas around 2 feet, building to 2
to 3 feet. Wave Detail: West 1 foot at 4 seconds. Winds and seas
higher in and around numerous showers and scattered thunderstorms.
.TONIGHT...West to northwest winds near 15 knots, decreasing to
10 to 15 knots. Seas 2 to 3 feet, subsiding to around 2 feet.
Wave Detail: West 1 foot at 3 seconds. Numerous showers and
scattered thunderstorms.
.WEDNESDAY...West winds 10 to 15 knots. Seas around 2 feet. Wave
Detail: West 2 feet at 3 seconds. Widespread showers and scattered
thunderstorms.
.WEDNESDAY NIGHT...West winds 10 to 15 knots. Seas around 2 feet.
Numerous showers and scattered thunderstorms.
.THURSDAY...Southwest to west winds near 15 knots. Seas 2 to 3
feet. Widespread showers and scattered thunderstorms.
.THURSDAY NIGHT...Southwest to west winds decreasing to 10 to 15
knots. Seas subsiding to around 2 feet. Numerous showers and
scattered thunderstorms.
.FRIDAY...Southwest to west winds 10 to 15 knots. Seas around 2
feet. Widespread showers and scattered thunderstorms.
.FRIDAY NIGHT...Southwest winds near 10 knots, decreasing to 5 to
10 knots. Seas subsiding to 1 to 2 feet. Scattered showers and
thunderstorms.
.SATURDAY...Southwest to west winds 5 to 10 knots. Seas around
1 foot. Scattered showers and thunderstorms.
.SATURDAY NIGHT...Winds becoming east to southeast 5 to 10 knots.
Seas around 1 foot. Scattered showers and thunderstorms.

$$

GMZ033-034-022030-
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-
419 AM EDT Tue Sep 2 2025

.TODAY...Northwest winds near 10 knots, increasing to 10 to 15
knots late in the afternoon. Seas around 2 feet, building to 2 to
3 feet. Wave Detail: West 1 foot at 4 seconds. Winds and seas
higher in and around numerous showers and scattered thunderstorms.
.TONIGHT...West to northwest winds 10 to 15 knots, decreasing to
near 10 knots. Seas 2 to 3 feet, subsiding to 1 to 2 feet. Wave
Detail: West 1 foot at 4 seconds. Numerous showers and scattered
thunderstorms.
.WEDNESDAY...West to northwest winds near 10 knots. Seas 1 to 2
feet. Wave Detail: West 2 feet at 3 seconds. Widespread showers
and scattered thunderstorms.
.WEDNESDAY NIGHT...West winds near 10 knots, becoming southwest to
west 10 to 15 knots late. Seas 1 to 2 feet. Widespread showers
and scattered thunderstorms.
.THURSDAY...Southwest to west winds 10 to 15 knots. Seas 1 to
3 feet. Widespread showers and scattered thunderstorms.
.THURSDAY NIGHT...Southwest to west winds near 15 knots,
decreasing to 10 to 15 knots. Seas 2 to 3 feet. Widespread
showers and scattered thunderstorms.
.FRIDAY...Southwest to west winds 10 to 15 knots. Seas 1 to 3
feet. Widespread showers and scattered thunderstorms.
.FRIDAY NIGHT...Southwest winds 10 to 15 knots, decreasing to near
10 knots. Seas subsiding to around 2 feet. Numerous showers and
scattered thunderstorms.
.SATURDAY...Southwest to west winds decreasing to 5 to 10 knots.
Seas subsiding to 1 to 2 feet. Scattered showers and
thunderstorms.
.SATURDAY NIGHT...Southwest to west winds near 5 knots, becoming
east to southeast 5 to 10 knots. Seas around 1 foot. Scattered
showers and thunderstorms.

$$