Gov. Bob McDonnell has declared a state of emergency in Virginia, as snow continues to pile up and knock out power to electric customers. By issuing the declaration, McDonnell authorizes state agencies to identify and position resources to respond rapidly to emergencies. That includes the Virginia National Guard, which has been authorized to bring up to 200 personnel for storm duty. More than 1 foot of snow has piled up in Virginia’s Shenandoah Valley as state police scramble to respond to hundreds of crashes and utility crews worked to restore power to more than 200,000 customers.