220
FZUS52 KCHS 180535
CWFCHS

Coastal Waters Forecast
National Weather Service Charleston SC
135 AM EDT Mon Aug 18 2025

South Santee River SC to Savannah GA out 20 NM and Savannah GA to
Altamaha Sound GA out 60 NM, including Charleston Harbor and
Grays Reef National Marine Sanctuary

AMZ300-181800-
135 AM EDT Mon Aug 18 2025

.Synopsis for the coastal waters of south coastal South Carolina
and north coastal Georgia...
Weak high pressure will build into the region early this week as
Hurricane Erin passes well offshore through the middle of the
week. A cold front could drop into the area late this week.

$$

AMZ330-181800-
Charleston Harbor-
135 AM EDT Mon Aug 18 2025

.REST OF TONIGHT...S winds 5 kt, becoming NW late.
.MON...N winds 5 kt, becoming SE in the afternoon.
.MON NIGHT...SE winds 5 kt, becoming NE after midnight.
.TUE...NE winds 10 to 15 kt with gusts to 20 kt. A chance of
showers and tstms in the afternoon.
.TUE NIGHT...NE winds 10 to 15 kt with gusts to 20 kt. A chance
of showers and tstms in the evening, then a slight chance of
showers after midnight.
.WED...N winds 15 to 20 kt. Waves 1 to 2 ft. A slight chance of
showers in the morning, then a chance of showers and tstms in the
afternoon.
.WED NIGHT...N winds 10 to 15 kt. A chance of showers and tstms
in the evening.
.THU...N winds 10 to 15 kt. A slight chance of showers and tstms.
.THU NIGHT...S winds 10 to 15 kt. A chance of showers and tstms.
.FRI...E winds 5 to 10 kt. A chance of showers and tstms.
.FRI NIGHT...SE winds 5 to 10 kt. A chance of showers and tstms.

Winds and waves higher in and near tstms.

Unless otherwise noted, waves 1 foot or less.

Charleston Harbor water temperature 85 degrees.

$$

AMZ350-181800-
Waters from South Santee River to Edisto Beach SC out 20 NM-
135 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT FROM LATE TONIGHT THROUGH
THURSDAY EVENING...

.REST OF TONIGHT...SE winds 5 kt, becoming NE late. Seas 2 to
3 ft. Wave Detail: E 2 ft at 9 seconds.
.MON...N winds 5 kt, becoming E in the afternoon. Seas 2 to 3 ft.
Wave Detail: SE 3 ft at 15 seconds and E 2 ft at 9 seconds.
.MON NIGHT...SE winds 5 to 10 kt, becoming E after midnight. Seas
3 to 4 ft, building to 4 to 5 ft after midnight. Wave Detail: SE
4 ft at 14 seconds, becoming SE 5 ft at 17 seconds.
.TUE...NE winds 15 to 20 kt with gusts to 25 kt. Seas 5 to 7 ft,
building to 7 to 9 ft in the afternoon. Wave Detail: SE 7 ft at
17 seconds, becoming SE 9 ft at 16 seconds. A slight chance of
showers in the morning, then a chance of showers and tstms in the
afternoon.
.TUE NIGHT...NE winds 20 kt with gusts to 25 kt. Seas 8 to 10 ft,
building to 9 to 11 ft after midnight. Wave Detail: SE 9 ft at
15 seconds, becoming SE 10 ft at 16 seconds. A chance of showers.
A chance of tstms, mainly in the evening.
.WED...N winds 20 to 25 kt with gusts to 30 kt. Seas 9 to 12 ft.
Wave Detail: SE 11 ft at 16 seconds. A chance of showers and
tstms.
.WED NIGHT...N winds 15 to 20 kt with gusts to 30 kt. Seas 10 to
12 ft, subsiding to 9 to 12 ft after midnight. A chance of
showers and tstms in the evening.
.THU...N winds 15 to 20 kt. Seas 8 to 10 ft.
.THU NIGHT...SE winds 10 to 15 kt. Seas 6 to 8 ft. A chance of
showers and tstms.
.FRI...E winds 10 to 15 kt. Seas 4 to 6 ft. A chance of showers
and tstms.
.FRI NIGHT...SE winds 10 to 15 kt. Seas 4 to 5 ft. A chance of
showers and tstms.

Winds and seas higher in and near tstms.

$$

AMZ352-181800-
Waters from Edisto Beach SC to Savannah GA out 20 NM-
135 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT FROM LATE TONIGHT THROUGH
THURSDAY EVENING...

.REST OF TONIGHT...E winds 5 kt. Seas 2 ft. Wave Detail: E 2 ft
at 4 seconds and E 2 ft at 9 seconds.
.MON...NE winds 5 to 10 kt, becoming E in the afternoon. Seas
2 to 3 ft. Wave Detail: E 2 ft at 9 seconds and E 1 foot at
4 seconds.
.MON NIGHT...SE winds 5 to 10 kt, becoming NE after midnight.
Seas 2 to 3 ft, building to 3 to 4 ft after midnight. Wave
Detail: SE 3 ft at 15 seconds and E 2 ft at 8 seconds, becoming
SE 4 ft at 14 seconds.
.TUE...NE winds 10 to 15 kt, increasing to 15 to 20 kt in the
afternoon. Seas 5 to 7 ft, building to 6 to 8 ft in the
afternoon. Wave Detail: SE 6 ft at 17 seconds, becoming SE 8 ft
at 16 seconds. A slight chance of showers and tstms in the
morning, then a chance of showers and tstms in the afternoon.
.TUE NIGHT...NE winds 15 to 20 kt with gusts to 25 kt. Seas 7 to
9 ft, building to 8 to 10 ft after midnight. Wave Detail: SE 9 ft
at 15 seconds. A chance of showers. A chance of tstms, mainly in
the evening.
.WED...N winds 15 to 20 kt with gusts to 25 kt. Seas 8 to 10 ft,
building to 9 to 11 ft in the afternoon. Wave Detail: SE 10 ft at
16 seconds. A chance of showers. A slight chance of tstms in the
morning, then a chance of tstms in the afternoon.
.WED NIGHT...N winds 15 kt with gusts to 20 kt. Seas 9 to 11 ft,
subsiding to 8 to 10 ft after midnight. A chance of showers and
tstms in the evening.
.THU...N winds 10 to 15 kt. Seas 8 to 10 ft. A slight chance of
showers and tstms.
.THU NIGHT...S winds 10 to 15 kt. Seas 6 to 8 ft. A chance of
showers and tstms.
.FRI...E winds 5 to 10 kt. Seas 4 to 6 ft. Showers likely with a
chance of tstms.
.FRI NIGHT...SE winds 10 to 15 kt. Seas 3 to 4 ft. Showers likely
with a chance of tstms.

Winds and seas higher in and near tstms.

$$

AMZ354-181800-
Waters from Savannah GA to Altamaha Sound GA out 20 NM, including
Grays Reef National Marine Sanctuary-
135 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT FROM LATE TONIGHT THROUGH
THURSDAY EVENING...

.REST OF TONIGHT...E winds 5 kt. Seas 2 ft. Wave Detail: E 2 ft
at 4 seconds and E 1 foot at 9 seconds. A slight chance of
showers and tstms.
.MON...NE winds 5 to 10 kt. Seas 2 to 3 ft. Wave Detail: E 2 ft
at 4 seconds and E 2 ft at 9 seconds. A slight chance of showers
and tstms.
.MON NIGHT...E winds 5 to 10 kt. Seas 3 to 4 ft, building to 4 to
5 ft after midnight. Wave Detail: SE 3 ft at 15 seconds and E
2 ft at 8 seconds, becoming E 4 ft at 14 seconds.
.TUE...NE winds 15 to 20 kt with gusts to 25 kt. Seas 5 to 7 ft,
building to 6 to 8 ft in the afternoon. Wave Detail: SE 6 ft at
16 seconds, becoming SE 8 ft at 16 seconds. A slight chance of
showers in the morning, then a chance of showers and tstms in the
afternoon.
.TUE NIGHT...NE winds 15 to 20 kt with gusts to 25 kt. Seas 7 to
9 ft, building to 8 to 10 ft after midnight. Wave Detail: SE 8 ft
at 15 seconds, becoming SE 9 ft at 15 seconds. A chance of
showers. A chance of tstms, mainly in the evening.
.WED...N winds 15 to 20 kt with gusts to 25 kt. Seas 8 to 10 ft,
building to 9 to 11 ft in the afternoon. Wave Detail: E 9 ft at
16 seconds and E 7 ft at 7 seconds, becoming E 9 ft at 16 seconds
and E 7 ft at 8 seconds. A chance of showers. A slight chance of
tstms in the morning, then a chance of tstms in the afternoon.
.WED NIGHT...N winds 10 to 15 kt with gusts to 20 kt. Seas 8 to
10 ft. A chance of showers and tstms in the evening.
.THU...N winds 10 to 15 kt. Seas 7 to 9 ft. A slight chance of
showers and tstms.
.THU NIGHT...S winds 10 to 15 kt. Seas 6 to 8 ft. A chance of
showers and tstms.
.FRI...SE winds 5 to 10 kt. Seas 5 to 7 ft. Showers likely with a
chance of tstms.
.FRI NIGHT...SE winds 10 to 15 kt. Seas 4 to 5 ft. Showers likely
with a chance of tstms.

Winds and seas higher in and near tstms.

$$

AMZ374-181800-
Waters from Savannah GA to Altamaha Sound GA from 20 to 60 NM-
135 AM EDT Mon Aug 18 2025

...SMALL CRAFT ADVISORY IN EFFECT FROM LATE TONIGHT THROUGH
FRIDAY MORNING...

.REST OF TONIGHT...E winds 5 to 10 kt. Seas 2 to 3 ft. Wave
Detail: NE 2 ft at 7 seconds and SE 2 ft at 9 seconds. A slight
chance of showers and tstms, then a chance of showers and tstms
late.
.MON...NE winds 5 to 10 kt. Seas 2 to 3 ft, building to 3 to 4 ft
in the afternoon. Wave Detail: NE 2 ft at 7 seconds and SE 2 ft
at 9 seconds, becoming NE 3 ft at 7 seconds and SE 2 ft at
8 seconds. A chance of showers with a slight chance of tstms.
.MON NIGHT...E winds 10 kt. Seas 4 to 5 ft, building to 5 to 7 ft
after midnight. Wave Detail: SE 4 ft at 15 seconds and E 3 ft at
7 seconds, becoming SE 6 ft at 16 seconds and E 3 ft at
7 seconds.
.TUE...NE winds 15 to 20 kt with gusts to 25 kt. Seas 7 to 9 ft,
building to 9 to 11 ft in the afternoon. Wave Detail: SE 8 ft at
16 seconds and NE 4 ft at 4 seconds, becoming SE 11 ft at
15 seconds and NE 5 ft at 5 seconds. A chance of showers with a
slight chance of tstms.
.TUE NIGHT...NE winds 20 kt with gusts to 25 kt. Seas 10 to
12 ft, building to 10 to 13 ft after midnight. Wave Detail: SE
11 ft at 15 seconds. A chance of showers and tstms.
.WED...N winds 20 to 25 kt with gusts to 30 kt. Seas 11 to 13 ft,
building to 11 to 14 ft in the afternoon. Wave Detail: SE 11 ft
at 16 seconds and NE 8 ft at 7 seconds, becoming SE 11 ft at
16 seconds and NE 8 ft at 8 seconds. A chance of showers and
tstms.
.WED NIGHT...N winds 15 to 20 kt with gusts to 25 kt. Seas 10 to
13 ft, subsiding to 9 to 12 ft after midnight. A chance of
showers and tstms, mainly in the evening.
.THU...N winds 15 to 20 kt. Seas 9 to 11 ft. A slight chance of
showers and tstms.
.THU NIGHT...S winds 10 to 15 kt. Seas 8 to 10 ft. A chance of
showers and tstms.
.FRI...E winds 5 to 10 kt. Seas 6 to 8 ft. Showers likely with a
chance of tstms.
.FRI NIGHT...SE winds 10 kt. Seas 5 to 7 ft. Showers likely with
a chance of tstms.

Winds and seas higher in and near tstms.

$$