* WHAT. Up to one half foot of inundation above ground level in low lying areas due to tidal flooding. * WHERE. Shoreline in St. Marys County. * WHEN. Until 5 PM EDT this afternoon, especially around the time of high tide. * IMPACTS. At 3.0 feet, yards are flooded on Saint George Island, and water will begin covering the road leading to the island, especially if there is wave action. * ADDITIONAL DETAILS. Tides one and a half to two feet above normal. The next two high tides at Point Lookout are at 1:43 AM and 1:49 PM. The next two high tides at Coltons Point are at 2:50 PM and 3:02 AM. The next two high tides at Piney Point are at 2:14 PM and 2:26 AM.

* WHAT. Southwest winds 10 to 15 kt with gusts up to 20 kt expected. * WHERE. Chesapeake Bay from Sandy Point MD to Drum Point MD, Tidal Potomac from Cobb Island MD to Smith Point VA, Eastern Bay, and Choptank River to Cambridge MD and the Little Choptank River. * WHEN. From 2 AM to noon EDT Thursday. * IMPACTS. Conditions will be hazardous to small craft.

A warm front accompanied by showers and a few thunderstorms will result in a brief period of wind gusts of 20 to 25 knots. Mariners should exercise extra caution if navigating the waters during this time.

* WHAT. Up to one half foot of inundation above ground level expected in low-lying areas near shorelines and tidal waterways. * WHERE. Westmoreland, Richmond, Northumberland, Lancaster, Middlesex and Eastern Essex Counties. * WHEN. From 10 PM EDT this evening through late tonight. * IMPACTS. Shallow flooding is possible in the most vulnerable locations near the waterfront and shoreline.

* WHAT. Flash flooding caused by excessive rainfall continues to be possible. * WHERE. Portions of DC, including the following , District of Columbia, Maryland, including the following areas, Anne Arundel, Central and Southeast Howard, Central and Southeast Montgomery, Northwest Howard, Northwest Montgomery, Prince Georges and Southern Baltimore, and northern Virginia, including the following areas, Arlington/Falls Church/Alexandria, Central and Southeast Prince William/Manassas/Manassas Park, Eastern Loudoun, Fairfax and Northwest Prince William. * WHEN. Until 10 PM EDT this evening. * IMPACTS. Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Flooding may occur in poor drainage and urban areas. Low-water crossings may be flooded. * ADDITIONAL DETAILS. - Multiple rounds of heavy showers and thunderstorms will move across the area today into this evening. Rainfall amounts of 1 to 2 inches are likely, with isolated amounts of 3 to 4 inches possible. - Please visit www.weather.gov/safety/flood for flood safety and preparedness information