FZUS51 KLWX 210857 CWFLWX Coastal Waters Forecast National Weather Service Baltimore MD/Washington DC 457 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. ANZ500-212300- 457 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. $$ ANZ535-212300- Tidal Potomac from Key Bridge to Indian Head- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. Isolated showers. .TODAY...NW winds 5 to 10 kt. Waves 1 ft. .TONIGHT...N winds 5 to 10 kt...becoming E after midnight. Waves 1 ft. .MON...SE winds 5 to 10 kt...becoming SW 15 kt with gusts to 25 kt in the afternoon. Waves 1 to 2 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 10 to 15 kt with gusts to 20 kt. Waves 1 ft. Widespread showers and scattered tstms. .TUE...NW winds 5 to 10 kt. Waves 1 ft. .TUE NIGHT...NW winds 5 to 10 kt. Waves 1 ft. .WED...NW winds 5 to 10 kt...becoming SE. Waves 1 ft. .THU...S winds 5 to 10 kt. Waves 1 ft. A chance of showers and tstms. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ536-212300- Tidal Potomac from Indian Head to Cobb Island- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. Isolated showers. .TODAY...NW winds 5 to 10 kt. Waves 1 ft. .TONIGHT...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. $$ ANZ537-212300- Tidal Potomac from Cobb Island to Smith Point- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. Isolated showers. .TODAY...NW winds 5 to 10 kt. Waves 1 ft. .TONIGHT...SE winds 5 to 10 kt. Waves 1 ft. .MON...S winds 15 to 20 kt with gusts to 25 kt. Waves 2 to 3 ft. Widespread showers and scattered tstms. .MON NIGHT...S winds 15 to 20 kt...becoming SW 10 to 15 kt after midnight. Gusts up to 25 kt. Waves 2 to 3 ft. Widespread showers and scattered tstms. .TUE...NW winds 5 to 10 kt. Waves 1 ft. A chance of showers. .TUE NIGHT...NW winds 5 to 10 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft. .THU...S winds around 5 kt...increasing to 10 to 15 kt. Waves 1 to 2 ft. A chance of showers. A chance of tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ530-212300- Chesapeake Bay north of Pooles Island- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. .TODAY...W winds 5 to 10 kt. Waves 1 ft. .TONIGHT...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 the afternoon. 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. $$ ANZ531-212300- Chesapeake Bay from Pooles Island to Sandy Point- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 10 kt. Waves 1 ft. Isolated showers. .TODAY...W winds 5 to 10 kt. Waves 1 ft. .TONIGHT...NW winds 5 to 10 kt...becoming E after midnight. Waves 1 ft. .MON...SE winds 10 to 15 kt...becoming S 15 to 20 kt in the afternoon. Gusts up to 25 kt. Waves 2 to 3 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 10 to 15 kt...becoming W after midnight. Gusts up to 20 kt. Waves 2 to 3 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 to 15 kt. Waves 1 to 2 ft. .TUE NIGHT...N winds 10 to 15 kt. Waves 2 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft or less. .THU...S winds 10 to 15 kt. Waves 1 to 2 ft. A chance of showers in the afternoon. A chance of showers and tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ538-212300- Patapsco River including Baltimore Harbor- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .REST OF THE OVERNIGHT...W winds 5 kt. Waves flat. Isolated showers. .TODAY...W winds 5 to 10 kt. Waves 1 ft. .TONIGHT...NW winds 5 to 10 kt...becoming E after midnight. Waves 1 ft. .MON...SE winds 10 to 15 kt...becoming S 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...becoming NW after midnight. Gusts up to 20 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 kt. Waves 1 ft. .TUE NIGHT...NW winds 10 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 and tstms. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ539-212300- Chester River to Queenstown MD- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 10 kt. Waves 1 ft. Isolated showers. .TODAY...W winds 10 kt. Waves 1 to 2 ft. .TONIGHT...NW winds 10 kt...becoming E in the late evening and overnight. Waves 1 to 2 ft. .MON...S winds 15 to 20 kt with gusts to 25 kt. Waves 1 to 2 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 10 to 15 kt with gusts to 20 kt. Waves 2 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 to 15 kt with gusts to 20 kt. Waves 1 to 2 ft. .TUE NIGHT...N winds 10 to 15 kt with gusts to 20 kt. Waves 2 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft or less. .THU...S winds 5 to 10 kt. Waves 1 ft. A chance of showers in the afternoon. A chance of showers and tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ532-212300- Chesapeake Bay from Sandy Point to North Beach- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 10 kt. Waves 1 ft. Isolated showers. .TODAY...W winds 5 to 10 kt. Waves 1 ft. .TONIGHT...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 2 to 3 ft. 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. $$ ANZ540-212300- Eastern Bay- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 10 kt. Waves 1 ft. Isolated showers. .TODAY...W winds 10 kt. Waves 1 ft. .TONIGHT...NW winds 10 kt...becoming SE in the late evening and overnight. Waves 1 ft. .MON...S winds 15 to 20 kt with gusts to 25 kt. Waves 2 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 15 to 20 kt with gusts to 25 kt. Waves 2 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 to 15 kt. Waves 1 ft. .TUE NIGHT...N winds 10 to 15 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft or less. .THU...S winds 10 to 15 kt. Waves 1 ft. A chance of showers in the afternoon. A chance of showers and tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ533-212300- Chesapeake Bay from North Beach to Drum Point- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. Isolated showers. .TODAY...W winds 5 to 10 kt. Waves 1 ft. .TONIGHT...SE winds 5 to 10 kt. Waves 1 ft. .MON...S winds 15 to 20 kt with gusts to 25 kt. Waves 2 ft... building to 4 ft in the afternoon. Widespread showers and scattered tstms. .MON NIGHT...SW winds 15 to 20 kt with gusts to 25 kt. Waves 2 to 3 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 kt. Waves 1 to 2 ft. .TUE NIGHT...N winds 10 kt. Waves 2 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 to 2 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. $$ ANZ541-212300- Choptank River to Cambridge MD and the Little Choptank River- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. Isolated showers. .TODAY...W winds 5 to 10 kt. Waves 1 ft. .TONIGHT...SE winds 5 to 10 kt. Waves 1 ft. .MON...S winds 15 to 20 kt with gusts to 25 kt. Waves 2 ft. Widespread showers and scattered tstms. .MON NIGHT...SW winds 15 to 20 kt with gusts to 25 kt. Waves 2 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 to 15 kt. Waves 1 ft. .TUE NIGHT...N winds 10 to 15 kt. Waves 1 ft. .WED...N winds 5 to 10 kt...becoming SE. Waves 1 ft or less. .THU...S winds 10 to 15 kt. Waves 1 to 2 ft. A chance of showers. A chance of tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ542-212300- Patuxent River to Broomes Island MD- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 5 kt. Waves less than 1 ft. Isolated showers. .TODAY...W winds 5 to 10 kt. Waves 1 ft. .TONIGHT...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. $$ ANZ534-212300- Chesapeake Bay from Drum Point to Smith Point- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 10 kt. Waves 1 ft. Isolated showers. .TODAY...NW winds 5 to 10 kt...becoming S late. Waves 1 ft. .TONIGHT...SE winds 10 kt. Waves 2 ft. .MON...S winds 15 to 20 kt. Gusts up to 20 kt... increasing to 30 kt in the afternoon. Waves 3 ft. Widespread showers and scattered tstms. .MON NIGHT...S winds 15 to 20 kt...becoming SW 10 to 15 kt after midnight. Gusts up to 25 kt. Waves 3 ft. Widespread showers and scattered tstms. .TUE...NW winds 10 to 15 kt. Waves 2 ft. A chance of showers. .TUE NIGHT...N winds 10 to 15 kt with gusts to 20 kt. Waves 2 ft. .WED...N winds 10 to 15 kt...diminishing to 5 kt in the afternoon, then becoming S. Waves 1 to 2 ft. .THU...S winds 10 to 15 kt. Waves 1 ft...building to 3 ft. A chance of showers and tstms through the night. Winds and waves higher and visibilities lower in and near tstms. $$ ANZ543-212300- Tangier Sound and the inland waters surrounding Bloodsworth Island- 457 AM EDT Sun Jun 21 2026 ...SMALL CRAFT ADVISORY IN EFFECT FROM MONDAY MORNING THROUGH MONDAY AFTERNOON... .REST OF THE OVERNIGHT...NW winds 10 kt. Waves 1 ft. Isolated showers. .TODAY...NW winds 5 to 10 kt...becoming SW late. Waves 1 ft. .TONIGHT...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. $$