* WHAT. Temperatures as low as 34 will result in frost formation. * WHERE. Portions of central, northern and southern Delaware, northeast Maryland, central and southern New Jersey and southeast Pennsylvania. * WHEN. From 2 AM to 9 AM EDT Friday. * IMPACTS. Frost could kill sensitive outdoor vegetation if left uncovered.

* WHAT. Temperatures as low as 34 will result in frost formation. * WHERE. Portions of central, northern and southern Delaware, northeast Maryland, central and southern New Jersey and southeast Pennsylvania. * WHEN. From 2 AM to 9 AM EDT Friday. * IMPACTS. Frost could kill sensitive outdoor vegetation if left uncovered.

* WHAT. Temperatures as low as 33 will result in frost formation. * WHERE. Portions of central, northern and southern Delaware, northeast Maryland, central and southern New Jersey and southeast Pennsylvania. * WHEN. Until 9 AM EDT this morning. * IMPACTS. Frost could kill sensitive outdoor vegetation if left uncovered.

A period of gusty easterly winds will persist through late evening. Occasional gusts to near 20 knots are possible. Mariners, especially those who are inexperienced or operating smaller vessels, should exercise extra caution if navigating the waters during this time.

* 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.

* WHAT. Temperatures as low as 33 will result in frost formation. * WHERE. Portions of central Pennsylvania. * WHEN. From 2 AM to 8 AM EDT Friday. * IMPACTS. Near-ground freezing temperatures could kill uncovered sensitive outdoor vegetation.