On February 28, 1999, about 1545 Eastern Standard Time, a Piper PA-28-140, N8790N, was substantially damaged during a landing at Lakes Region Airport, Wolfeboro, New Hampshire. The certificated private pilot sustained serious injuries, and the passenger sustained minor injuries. Instrument meteorological conditions prevailed for flight that originated from Alton Bay Seaplane Base, Alton Bay, New Hampshire about 1530. No flight plan was filed for the personal flight conducted under 14 CFR Part 91. The pilot reported that he departed Alton Bay Seaplane Base, and planned to fly to Laconia Municipal Airport, Laconia, New Hampshire. While en route, the pilot diverted to Lakes Region Airport due to a snow storm to the north. The pilot stated that the approach end to Runway 12 was "...white out conditions." Therefore, he landed on Runway 30, approximately 1,250 beyond the approach end of the 2,540 foot long and 50 foot wide runway. The airplane bounced, skidded, and struck a pile of dirt about 50 feet beyond the departure end of the runway. The pilot was not instrument rated. He stated that if he had known about weather, he never would have departed the Alton Bay Seaplane Base. The pilot did not obtain a weather briefing from a Flight Service Station; however, he had listened to the Automated Weather Observation System (AWOS) at Laconia Municipal Airport. According to the pilot, the weather was reported to be: ceiling 6,500 overcast; and scattered rain showers. The passenger stated that the pilot flew about 4 miles of the 13 mile trip, when he diverted to Lakes Region Airport. The airport was to the east, the only area where the weather was still clear. The Lakes Region Airport Manager was on the taxiway when the pilot landed. The manager said the pilot approached Runway 30 "...very fast and very high with a 10-15 knot tailwind..." He landed approximately 1,500 feet beyond the approach end of Runway 30, bounced several times, and skidded off the end of the runway. The manager further stated that snow showers surrounded the airport, but the weather was still clear to the east. According to a Federal Aviation Administration Inspector, the runway was dry, and braking action was good. The airplane left skid marks at the end of Runway 30. The inspector further stated the airplane struck a pile of dirt and proceeded down a 6 to 10 foot "drop-off". A review of the Laconia Municipal Airport AWOS, revealed that at 1355, approximately 1 hour 50 minutes before the accident, the weather was: winds from 080 degrees at 7 knots; visibility 10 statute miles; ceiling 6,500 feet overcast; and altimeter 29.76" Hg. The AWOS further revealed that at 1555, approximately 10 minutes after the accident, the weather was: winds from 060 degrees at 9 knots; visibility 1 1/4 statute miles; ceiling 100 feet overcast; and altimeter 29.69" Hg.