FZUS51 KLWX 210627 CWFLWX Coastal Waters Forecast National Weather Service Baltimore MD/Washington DC 226 AM EDT Sun Jun 21 2026 Tidal Potomac River and Maryland portion of Chesapeake Bay. Forecasts of wave heights do not include effects of wind direction relative to tidal currents. Expect higher waves when winds are blowing against the tidal flow. Waves flat where waters are iced over. ANZ500-212000- 226 AM EDT Sun Jun 21 2026 .SYNOPSIS FOR THE TIDAL POTOMAC AND MD PORTION OF THE CHESAPEAKE BAY... High pressure will build near the area over the weekend before a frontal system approaches the area Monday. Small Craft Advisories will likely be needed for portions of the waters Monday night into Tuesday. Special Marine Warnings may be needed as thunderstorms track over the waters Monday afternoon and evening. $$ ANZ535-212000- Tidal Potomac from Key Bridge to Indian Head- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. .SUN...NW winds 5 to 10 kt. Waves 1 ft. .SUN NIGHT...N winds 5 to 10 kt...becoming E after midnight. Waves 1 ft. .MON...SE winds 5 to 10 kt...becoming SW 15 kt with gusts to 25 kt in the afternoon. Waves 1 to 2 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft. Widespread showers and scattered tstms. .TUE...NW winds 5 to 10 kt. Waves 1 ft. .TUE NIGHT...NW winds 5 to 10 kt. Waves 1 ft. .WED...NW winds 5 to 10 kt...becoming SE. Waves 1 ft or less. .THU...S winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ536-212000- Tidal Potomac from Indian Head to Cobb Island- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. .SUN...NW winds 5 to 10 kt. Waves 1 ft. .SUN NIGHT...E winds 5 to 10 kt. Waves 1 ft. .MON...S winds 5 to 10 kt...increasing to 15 kt with gusts to 25 kt in the afternoon. Waves 1 to 2 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft. Widespread showers and scattered tstms. .TUE...NW winds 5 to 10 kt. Waves 1 ft. .TUE NIGHT...NW winds 5 to 10 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft. .THU...S winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ537-212000- Tidal Potomac from Cobb Island to Smith Point- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .OVERNIGHT...NW winds 5 kt. Waves flat. .SUN...NW winds 5 to 10 kt. Waves 1 ft or less. .SUN NIGHT...SE winds 5 to 10 kt. Waves 1 ft. .MON...S winds 15 to 20 kt with gusts to 25 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .MON NIGHT...S winds 15 to 20 kt...becoming SW 10 to 15 kt after midnight. Gusts up to 25 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .TUE...NW winds 5 to 10 kt. Waves 1 ft. A chance of showers. .TUE NIGHT...NW winds 5 to 10 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft. .THU...S winds around 5 kt...increasing to 10 to 15 kt. Waves 1 to 2 ft. A chance of showers. A chance of tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ530-212000- Chesapeake Bay north of Pooles Island- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. .SUN...W winds 5 to 10 kt. Waves 1 ft. .SUN NIGHT...NW winds 5 to 10 kt...becoming E after midnight. Waves 1 ft. .MON...SE winds 10 to 15 kt...becoming S 15 to 20 kt in theafternoon. Gusts up to 25 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 10 to 15 kt...becoming W 5 to 10 kt after midnight. Gusts up to 20 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .TUE...NW winds 5 to 10 kt. Waves 1 ft. .TUE NIGHT...N winds 5 to 10 kt. Waves 1 ft. .WED...NW winds 5 to 10 kt...becoming S. Waves 1 ft or less. .THU...S winds 5 to 10 kt. Waves 1 ft. A chance of showers. A chance of tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ531-212000- Chesapeake Bay from Pooles Island to Sandy Point- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .OVERNIGHT...W winds 10 kt. Waves flat. .SUN...W winds 5 to 10 kt. Waves 1 ft. .SUN NIGHT...NW winds 5 to 10 kt...becoming E after midnight. Waves 1 ft or less. .MON...SE winds 10 to 15 kt...becoming S 15 to 20 kt in the afternoon. Gusts up to 25 kt. Waves 2 to 3 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 10 to 15 kt...becoming W after midnight. Gusts up to 20 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 to 15 kt. Waves 1 ft. .TUE NIGHT...N winds 10 to 15 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft or less. .THU...S winds 10 to 15 kt. Waves 1 to 2 ft. A chance of showers in the afternoon. A chance of showers and tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ538-212000- Patapsco River including Baltimore Harbor- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .OVERNIGHT...W winds 5 kt. Waves flat. .SUN...W winds 5 to 10 kt. Waves 1 ft or less. .SUN NIGHT...NW winds 5 to 10 kt...becoming E after midnight. Waves 1 ft or less. .MON...SE winds 10 to 15 kt...becoming S with gusts to 25 kt in the afternoon. Waves 1 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 10 to 15 kt...becoming NW after midnight. Gusts up to 20 kt. Waves 1 ft or less. Widespread showers and scattered tstms. .TUE...NW winds 10 kt. Waves 1 ft. .TUE NIGHT...NW winds 10 kt. Waves 1 ft or less. .WED...N winds 5 to 10 kt...becoming SE. Waves flat. .THU...S winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ539-212000- Chester River to Queenstown MD- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .OVERNIGHT...NW winds 10 kt. Waves flat. .SUN...W winds 10 kt. Waves 1 ft. .SUN NIGHT...NW winds 10 kt...becoming E in the late evening and overnight. Waves 1 ft or less. .MON...S winds 15 to 20 kt with gusts to 25 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 10 to 15 kt with gusts to 20 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft. .TUE NIGHT...N winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft or less. .THU...S winds 5 to 10 kt. Waves 1 ft. A chance of showers in the afternoon. A chance of showers and tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ532-212000- Chesapeake Bay from Sandy Point to North Beach- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .OVERNIGHT...NW winds 10 kt. Waves flat. .SUN...W winds 5 to 10 kt. Waves 1 ft. .SUN NIGHT...W winds 10 kt...becoming SE in the late evening and overnight. Waves 1 ft. .MON...S winds 15 to 20 kt with gusts to 25 kt. Waves 2 to 3 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 15 to 20 kt with gusts to 25 kt. Waves 3 ft... subsiding to 1 ft after midnight. Widespread showers and scattered tstms. .TUE...NW winds 10 kt. Waves 1 ft. .TUE NIGHT...NW winds 10 to 15 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft or less. .THU...S winds 10 to 15 kt. Waves 1 ft...building to 2 to 3 ft. A chance of showers in the afternoon. A chance of showers and tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ540-212000- Eastern Bay- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .OVERNIGHT...NW winds 10 kt. Waves flat. .SUN...W winds 10 kt. Waves 1 ft. .SUN NIGHT...NW winds 10 kt...becoming SE in the late evening and overnight. Waves flat. .MON...S winds 15 to 20 kt with gusts to 25 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 15 to 20 kt with gusts to 25 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 to 15 kt. Waves 1 ft. .TUE NIGHT...N winds 10 to 15 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft or less. .THU...S winds 10 to 15 kt. Waves 1 ft. A chance of showers in the afternoon. A chance of showers and tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ533-212000- Chesapeake Bay from North Beach to Drum Point- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. .SUN...W winds 5 to 10 kt. Waves 1 ft. .SUN NIGHT...SE winds 5 to 10 kt. Waves 1 ft. .MON...S winds 15 to 20 kt with gusts to 25 kt. Waves 2 to 3 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 15 to 20 kt with gusts to 25 kt. Waves 3 ft... subsiding to 1 ft after midnight. Widespread showers and scattered tstms. .TUE...NW winds 10 kt. Waves 2 ft. .TUE NIGHT...N winds 10 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft. .THU...S winds 10 to 15 kt. Waves 1 ft...building to 2 to 3 ft. A chance of showers. A chance of tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ541-212000- Choptank River to Cambridge MD and the Little Choptank River- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .OVERNIGHT...NW winds 10 kt. Waves 1 ft or less. .SUN...W winds 5 to 10 kt. Waves 1 ft or less. .SUN NIGHT...SE winds 5 to 10 kt. Waves 1 ft or less. .MON...S winds 15 to 20 kt with gusts to 25 kt. Waves 2 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 15 to 20 kt with gusts to 25 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 to 15 kt. Waves 1 ft. .TUE NIGHT...N winds 10 to 15 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft or less. .THU...S winds 10 to 15 kt. Waves 1 to 2 ft. A chance of showers. A chance of tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ542-212000- Patuxent River to Broomes Island MD- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. .SUN...W winds 5 to 10 kt. Waves 1 ft. .SUN NIGHT...SE winds 5 to 10 kt. Waves 1 ft. .MON...S winds 15 to 20 kt. Gusts up to 25 kt in the afternoon. Waves 1 ft. Widespread showers and scattered tstms. .MON NIGHT...S winds 15 kt...becoming SW after midnight. Gusts up to 20 kt. Waves 1 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 kt. Waves 1 ft. A chance of showers. .TUE NIGHT...NW winds 10 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft. .THU...S winds around 5 kt...increasing to 10 to 15 kt. Waves 1 ft. A chance of showers. A chance of tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ534-212000- Chesapeake Bay from Drum Point to Smith Point- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .OVERNIGHT...NW winds 10 kt. Waves 1 ft. .SUN...NW winds 5 to 10 kt...becoming S late. Waves 1 ft. .SUN NIGHT...SE winds 10 kt. Waves 1 ft. .MON...S winds 15 to 20 kt. Gusts up to 20 kt... increasing to 30 kt in the afternoon. Waves 2 ft...building to 4 ft in the afternoon. Widespread showers and scattered tstms. .MON NIGHT...S winds 15 to 20 kt...becoming SW 10 to 15 kt after midnight. Gusts up to 25 kt. Waves 4 ft... subsiding to 2 ft after midnight. Widespread showers and scattered tstms. .TUE...NW winds 10 to 15 kt. Waves 2 ft. A chance of showers. .TUE NIGHT...N winds 10 to 15 kt with gusts to 20 kt. Waves 1 to 2 ft. .WED...N winds 10 to 15 kt...diminishing to 5 kt in the afternoon, then becoming S. Waves 1 ft. .THU...S winds 10 to 15 kt. Waves 1 ft...building to 3 ft. A chance of showers and tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ543-212000- Tangier Sound and the inland waters surrounding Bloodsworth Island- 226 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .OVERNIGHT...NW winds 10 kt. Waves 1 ft. .SUN...NW winds 5 to 10 kt...becoming SW late. Waves 1 ft. .SUN NIGHT...SE winds 10 kt. Waves 1 ft. .MON...S winds 10 to 15 kt with gusts to 20 kt... increasing to 20 kt with gusts to 30 kt in the afternoon. Waves 2 to 3 ft. Widespread showers and scattered tstms. .MON NIGHT...S winds 15 to 20 kt. Gusts up to 30 kt... diminishing to 20 kt after midnight. Waves 2 to 3 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 kt. Waves 1 ft. A chance of showers. .TUE NIGHT...N winds 10 to 15 kt. Waves 1 ft. .WED...N winds 10 to 15 kt...becoming NW 5 kt in the afternoon, then becoming S. Waves 1 ft. .THU...S winds 10 to 15 kt. Waves 1 to 2 ft. A chance of showers and tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$