Heavy rain will continue overnight, but then it's all about the frigid cold.
Rain showers picked up Saturday evening and will stick around through about 9 a.m. Sunday.
Storm Team4 Meteorologist Somara Theodore says flooding could become a problem overnight Saturday and into Sunday.
A winter weather advisory is in effect for Frederick County, Maryland, and counties along I-81 until 6 a.m. Sunday. Go here to see all weather alerts.
Areas north and west of D.C. that are under the advisory will see some snow, sleet and ice Saturday night.
In areas where temperatures remain near or below freezing — including western Maryland, southern Pennsylvania and eastern West Virginia — rain could cause a significant amount of ice accumulation that cause power outages and issues with trees. Traveling on Interstates 70, 68 and 81 could become difficult and dangerous.
Any snow will change over to rain by 1 a.m. Sunday, Theodore said.
In the D.C. region, a wind advisory takes effect from 11 a.m. to 7 p.m. Sunday.
On Sunday, the temperature will drop from the high 40s in the morning into the teens by sunset.
Wind gusts could reach 50 mph by Sunday afternoon and the strong winds will likely push the feels-like temperatures down to below zero by Sunday night and early Monday morning, Theodore said.
Some Amtrak trains running out of Union Station were set to run on a modified schedule Saturday and Sunday because of the expected weather.
More than a dozen flights at Reagan National Airport were cancelled Saturday as a storm system slated to affect 111 million people across the country headed eastward.
BWI said conditions are normal. Some flights to Chicago, which was slammed with snow, were canceled, the airport authority said. Dulles reported isolated cancellations.
Monday also will be bitterly cold. Expect a high of 20 degrees Monday with a wind chills of -10 to 10.
Then, temperatures will climb back into the 40s by midweek.
D.C. Fire and EMS released a list of resources for anyone who needs shelter.
Aside from the rain and cold, there is a total lunar eclipse starting at about 11 p.m. Sunday.