639
FZUS52 KCHS 171040
CWFCHS

Coastal Waters Forecast
National Weather Service Charleston SC
640 AM 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

AMZ300-172300-
640 AM EDT Sun Aug 17 2025

.Synopsis for the coastal waters of south coastal South Carolina
and north coastal Georgia...
A weak backdoor boundary will work southward across the area
today and tonight. High pressure will then build into the region
through early next week as Hurricane Erin passes well offshore
through the middle of the coming week.

$$

AMZ330-172300-
Charleston Harbor-
640 AM EDT Sun Aug 17 2025

.TODAY...NE winds 5 to 10 kt, becoming E this afternoon. Patchy
fog early this morning. A slight chance of showers and tstms this
morning. A chance of showers and tstms early this afternoon, then
a slight chance of showers and tstms late.
.TONIGHT...E winds 5 to 10 kt, becoming N after midnight.
.MON...N winds 5 kt, becoming SE in the afternoon.
.MON NIGHT...SE winds 5 to 10 kt, becoming NE after midnight.
.TUE...NE winds 10 to 15 kt. 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, then a slight chance of showers after midnight.
.WED...N winds 10 to 15 kt. A chance of showers and tstms.
.WED NIGHT...NW winds 10 to 15 kt.
.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.

Winds and waves higher in and near tstms.

Unless otherwise noted, waves 1 foot or less.

Charleston Harbor water temperature 84 degrees.

$$

AMZ350-172300-
Waters from South Santee River to Edisto Beach SC out 20 NM-
640 AM EDT Sun Aug 17 2025

.TODAY...NE winds 10 kt, becoming E late. Seas 2 to 3 ft. Wave
Detail: NE 2 ft at 3 seconds and SE 2 ft at 9 seconds. A chance
of showers and tstms.
.TONIGHT...E 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.
.MON...N winds 5 to 10 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 10 kt, becoming E after midnight. Seas 3 to
4 ft, building to 4 to 6 ft after midnight. Wave Detail: SE 4 ft
at 15 seconds, becoming SE 5 ft at 16 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 7 ft at 16 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 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 16 seconds, becoming SE 9 ft at 15 seconds. A chance of
showers and tstms.
.WED...N winds 15 to 20 kt. Seas 9 to 11 ft. A chance of showers
and tstms.
.WED NIGHT...N winds 15 kt. Seas 8 to 10 ft. A slight chance of
showers and tstms.
.THU...NE winds 10 to 15 kt. Seas 6 to 8 ft. A slight chance of
showers and tstms.
.THU NIGHT...S winds 10 to 15 kt. Seas 4 to 5 ft. A chance of
showers and tstms.

Winds and seas higher in and near tstms.

$$

AMZ352-172300-
Waters from Edisto Beach SC to Savannah GA out 20 NM-
640 AM EDT Sun Aug 17 2025

.TODAY...NE winds 5 to 10 kt, becoming E late. Seas 2 ft. Wave
Detail: NE 2 ft at 3 seconds and SE 1 foot at 10 seconds. A
chance of showers and tstms.
.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 slight chance of showers
and tstms in the evening.
.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 10 kt, becoming E after midnight. Seas 2 to
3 ft, building to 4 to 5 ft after midnight. Wave Detail: SE 3 ft
at 16 seconds and E 2 ft at 8 seconds, becoming SE 4 ft at
16 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 6 ft at 16 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 15 kt with gusts to 20 kt. Seas 6 to 8 ft,
building to 7 to 9 ft after midnight. Wave Detail: SE 8 ft at
15 seconds. A chance of showers. A chance of tstms, mainly in the
evening.
.WED...N winds 15 to 20 kt. Seas 7 to 9 ft. A chance of showers
and tstms.
.WED NIGHT...NW winds 10 to 15 kt. Seas 7 to 9 ft. A slight
chance of showers and tstms.
.THU...N winds 10 to 15 kt. Seas 6 to 8 ft. A slight chance of
showers and tstms.
.THU NIGHT...S winds 10 kt. Seas 4 to 6 ft. A chance of showers
and tstms.

Winds and seas higher in and near tstms.

$$

AMZ354-172300-
Waters from Savannah GA to Altamaha Sound GA out 20 NM, including
Grays Reef National Marine Sanctuary-
640 AM EDT Sun Aug 17 2025

.TODAY...NE winds 5 to 10 kt. Seas 2 ft. Wave Detail: NE 2 ft at
3 seconds and E 1 foot at 10 seconds. A chance of showers and
tstms.
.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 chance of showers and
tstms, mainly in the evening.
.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 10 kt. Seas 3 to 4 ft, building to 4 to 5 ft
after midnight. Wave Detail: SE 3 ft at 16 seconds and E 2 ft at
8 seconds, becoming SE 4 ft at 16 seconds.
.TUE...NE winds 10 to 15 kt with gusts to 20 kt. Seas 4 to 6 ft,
building to 6 to 8 ft in the afternoon. Wave Detail: SE 6 ft at
15 seconds, becoming SE 7 ft at 15 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. Seas 7 to 9 ft. Wave Detail:
SE 8 ft at 15 seconds and E 5 ft at 8 seconds. A chance of
showers. A chance of tstms, mainly in the evening.
.WED...N winds 15 to 20 kt. Seas 7 to 9 ft. A chance of showers
and tstms.
.WED NIGHT...SW winds 10 to 15 kt. Seas 7 to 9 ft. A slight
chance of showers and tstms.
.THU...N winds 10 to 15 kt. Seas 6 to 7 ft. A chance of showers
and tstms.
.THU NIGHT...S winds 10 to 15 kt. Seas 5 to 7 ft. A chance of
showers and tstms.

Winds and seas higher in and near tstms.

$$

AMZ374-172300-
Waters from Savannah GA to Altamaha Sound GA from 20 to 60 NM-
640 AM EDT Sun Aug 17 2025

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

Winds and seas higher in and near tstms.

$$