The latest forecast Saturday suggests up to a foot of snow is possible for parts of Northern Virginia, according to the National Weather Service.
A winter storm warning was expanded overnight to include all of the Washington metro area from 4 p.m. Saturday until 6 p.m. Sunday.
The latest forecast shows 8-12 inches possible for most of the region and 6-8 inches for communities inside the Beltway, in northern Fairfax County and greater Leesburg.
The warning means that severe winter weather conditions could make travel very difficult with snow-covered and slippery roads, according to the weather alert.
“If you must travel, keep an extra flashlight, food and water in your vehicle in case of an emergency,” forecasters noted.
The snow is expected to begin Saturday afternoon. The Virginia Department of Transportation is asking that drivers avoid unnecessary travel during the storm.
Starting Saturday afternoon, the Virginia Department of Transportation will begin staging snowplows along major routes through Northern Virginia.
The snow will also impact Interstate 95 Express Lanes reversals. The toll lanes will be open southbound all day Saturday, with northbound reversal beginning Sunday at 2 p.m. The lanes should be open northbound by 4 p.m.