Expires:202101200900;;182770 FZUS51 KLWX 192344 CWFLWX Coastal Waters Forecast National Weather Service Baltimore MD/Washington DC 644 PM EST Tue Jan 19 2021 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. ANZ500-200900- 644 PM EST Tue Jan 19 2021 .SYNOPSIS FOR THE TIDAL POTOMAC AND MD PORTION OF THE CHESAPEAKE BAY... High pressure will remain south of the waters through this evening. A weak cold front will pass through the waters late tonight into Wednesday morning. High pressure will briefly build overhead Wednesday night before moving offshore Thursday. Canadian high pressure will build toward the waters waters late in the week into the weekend. There is a potential for Gale Force winds Wednesday, and Small Craft Advisories will likely be needed for at least portions of the waters Wednesday night through Saturday. $$