340
FZUS52 KCHS 172230
CWFCHS

Coastal Waters Forecast
National Weather Service Charleston SC
630 PM EDT Sun Aug 17 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

AMZ300-181100-
630 PM EDT Sun Aug 17 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 later in the week.

$$

AMZ330-181100-
Charleston Harbor-
630 PM EDT Sun Aug 17 2025

.TONIGHT...E winds 5 to 10 kt, becoming S after midnight, then
becoming light and variable late. A slight chance of showers and
tstms early this evening.
.MON...N winds 5 kt, becoming SE in the afternoon.
.MON NIGHT...SE winds 5 to 10 kt, becoming E after midnight.
.TUE...NE winds 5 to 10 kt, increasing to 10 to 15 kt with gusts
to 20 kt in the afternoon. A chance of showers and tstms in the
afternoon.
.TUE NIGHT...NE winds 10 to 15 kt. A chance of showers and tstms
in the evening.
.WED...N winds 10 to 15 kt. A slight chance of showers and tstms
in the afternoon.
.WED NIGHT...N winds 5 to 10 kt. A slight chance of showers and
tstms in the evening.
.THU...NE winds 10 kt. A chance of showers and tstms.
.THU NIGHT...S winds 5 to 10 kt. A chance of showers and tstms.
.FRI...E winds 5 to 10 kt. Showers likely with a chance of 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.

$$

AMZ350-181100-
Waters from South Santee River to Edisto Beach SC out 20 NM-
630 PM EDT Sun Aug 17 2025

...SMALL CRAFT ADVISORY IN EFFECT FROM LATE MONDAY NIGHT THROUGH
THURSDAY EVENING...

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

Winds and seas higher in and near tstms.

$$

AMZ352-181100-
Waters from Edisto Beach SC to Savannah GA out 20 NM-
630 PM EDT Sun Aug 17 2025

...SMALL CRAFT ADVISORY IN EFFECT FROM LATE MONDAY NIGHT THROUGH
THURSDAY EVENING...

.TONIGHT...E winds 5 to 10 kt. Seas 2 ft. Wave Detail: E 2 ft at
4 seconds and E 1 foot at 9 seconds. A chance of showers and
tstms early this evening. A slight chance of showers and tstms
after midnight.
.MON...N winds 5 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...E winds 5 to 10 kt. 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 5 to 10 kt, increasing to 10 to 15 kt with gusts
to 20 kt in the afternoon. Seas 4 to 6 ft, building to 6 to 8 ft
in the afternoon. Wave Detail: SE 5 ft at 15 seconds, becoming SE
7 ft at 15 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 10 to 15 kt with gusts to 20 kt. Seas 6 to
8 ft, building to 7 to 8 ft after midnight. Wave Detail: SE 8 ft
at 15 seconds. A chance of showers and tstms.
.WED...N winds 10 to 15 kt with gusts to 20 kt. Seas 7 to 9 ft.
Wave Detail: SE 9 ft at 15 seconds. A slight chance of showers
and tstms.
.WED NIGHT...N winds 5 to 10 kt, becoming NW after midnight. Seas
7 to 9 ft. A slight chance of showers and tstms.
.THU...N winds 5 to 10 kt. Seas 7 to 9 ft. A chance of showers
and tstms.
.THU NIGHT...S winds 5 to 10 kt. Seas 5 to 7 ft. A chance of
showers and tstms.
.FRI...E winds 5 to 10 kt. Seas 4 to 5 ft. Showers likely with a
chance of tstms.
.FRI NIGHT...SE winds 5 to 10 kt. Seas 2 to 3 ft. Showers likely
with a chance of tstms.

Winds and seas higher in and near tstms.

$$

AMZ354-181100-
Waters from Savannah GA to Altamaha Sound GA out 20 NM, including
Grays Reef National Marine Sanctuary-
630 PM EDT Sun Aug 17 2025

...SMALL CRAFT ADVISORY IN EFFECT FROM LATE MONDAY NIGHT THROUGH
THURSDAY EVENING...

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

Winds and seas higher in and near tstms.

$$

AMZ374-181100-
Waters from Savannah GA to Altamaha Sound GA from 20 to 60 NM-
630 PM EDT Sun Aug 17 2025

...SMALL CRAFT ADVISORY IN EFFECT FROM LATE MONDAY NIGHT THROUGH
FRIDAY MORNING...

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

Winds and seas higher in and near tstms.

$$