* WHAT. Visibility one quarter mile or less in dense fog. * WHERE. Portions of western Maryland, the Shenandoah Valley and central piedmont of Virginia, and eastern West Virginia. * WHEN. Until 10 AM EDT this morning. * IMPACTS. Low visibility could make driving conditions hazardous.

* WHAT. Up to one foot of inundation above ground level in low lying areas due to tidal flooding. * WHERE. Shoreline in the District of Columbia. * WHEN. Until 9 AM EDT Tuesday, especially around the time of high tide. * IMPACTS. Shoreline inundation is expected along portions of the seawall adjacent to Ohio Drive and the Hains Point Loop Road, and near the Tidal Basin and Jefferson Memorial. * ADDITIONAL DETAILS. Tides one and a half to two feet above normal. High tide at Washington Channel is at 6:49 AM this morning, 7:13 PM this evening, and 7:28 AM Tuesday morning.

* WHAT. Up to one half foot of inundation above ground level in low lying areas due to tidal flooding. * WHERE. Shoreline in St. Mary's County. * WHEN. Until 3 AM EDT Tuesday, 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. High tide at Piney Point is at 1:19 PM this afternoon and 1:34 AM overnight. High tide at Point Lookout is at 11:52 AM this morning and 12:41 AM overnight. High tide at Coltons Point is at 1:55 PM this afternoon and 2:10 AM overnight.

* WHAT. For the first Coastal Flood Advisory, up to one half foot of inundation above ground level in low lying areas due to tidal flooding. For the second Coastal Flood Advisory, up to one foot of inundation above ground level expected in low lying areas due to tidal flooding. * WHERE. Shoreline in Anne Arundel County. * WHEN. For the first Coastal Flood Advisory, until 7 AM EDT this morning, especially around the time of high tide. For the second Coastal Flood Advisory, from midnight tonight to 9 AM EDT Tuesday, especially around the time of high tide. * IMPACTS. At 3.0 feet, Compromise Street begins to flood in Annapolis. Flooding of much of the City Dock parking lot is occurring. * ADDITIONAL DETAILS. Tides one and a half to two feet above normal. The affected high tides at Annapolis U.S. Naval Academy are at 4:07 AM early this morning, and 4:47 AM early Tuesday morning.

Recent observations and traffic cameras show fog developing over inland portions of Virginia. Currently, the lowest visibilities are from I-95 and points to the west. Fog is expected to expand further and become more widespread closer to sunrise with visibilities between a quarter and one half mile. Visibilities could drop below a quarter mile at times. Motorists should be alert for sudden changes in visibility due to the areas of dense fog. Drive at reduced speeds. watch for children at school bus stops. and use low beam headlights only.