If driving, slow down, use your headlights, and leave plenty ofdistance ahead of you.
* WHAT...Visibility one quarter mile or less in dense fog.* WHERE...Portions of the Shenandoah Valley, Central VirginiaPiedmont, West Virginia Panhandle, and Northern Maryland.* WHEN...Until 10 AM EDT this morning.* IMPACTS...Low visibility could make driving conditions hazardous.