IN A FOG: The Washington waterfront took on an eerie quality Thursday as fog rose from the Pamlico River and, in some places, crept over its shoreline. Advection fog is formed when warm air is cooled by a much cooler surface beneath it. In this case, it was river water still thawing out after last week’s freeze. Visibility on the water was greatly reduced as the chilly fog hung around for the day. (Vail Stewart Rumley/Daily News)