* WHAT. Temperatures as low as 36 will result in frost formation. * WHERE. Carroll, Cecil, Northern Baltimore, Northwest Harford, and Southeast Harford Counties. * WHEN. From 2 AM to 8 AM EDT Friday. * IMPACTS. Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered.

* WHAT. Up to one foot of inundation above ground level expected in low lying areas due to tidal flooding. * WHERE. Shoreline in the District of Columbia. * WHEN. From 8 AM to 1 PM EDT Friday, 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 to one and a half feet above normal. The next high tides at Washington Channel are at 10:15 PM and 10:13 AM.

* WHAT. 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. From 2 AM to noon EDT Friday, especially around the time of high tide. * IMPACTS. At 3.2 feet, water begins to approach businesses on Dock Street in Annapolis. The City Dock parking lot is flooded. Compromise Street is flooded. * ADDITIONAL DETAILS. Tides one and a half to two feet above normal. The next high tide at Annapolis U.S. Naval Academy is at 7:42 AM.