Gov. Bob McDonnell has declared a state of emergency for southern Virginia due to an approaching winter storm. McDonnell issued the declaration Thursday evening. It authorizes state agencies to help local government respond to the storm. The governor’s office says areas south of southwest Virginia to Hampton Roads are expected to take the brunt of the store, which could bring significant snow. Among other things, the State Police and Department of Transportation are preparing to keep roadways clear and assist motorists and the National Guard has put 200 soldiers on standby.