The pilot stated that he was in cruise flight at 2,500 feet when he encountered low clouds and fog. He lost visual contact with the ground and initiated a climbing left turn. Seconds later, he impacted rising terrain which resulted in substantial damaged to the wings, fuselage, and the empennage. Prior to the flight, the pilot obtained a weather briefing from a flight service station that forecasted overcast ceilings at 3,000 feet and 10 miles visibility near the route of flight with conditions improving throughout the day. The pilot stated the weather at the time of the accident was approximately 5 miles visibility, with an overcast ceiling at 3,000 feet.