MANILA, Philippines—A powerful typhoon that battered the central Philippines left at least 12 people dead in massive floods that trapped residents on roofs and damaged buildings including a hotel and an airport, officials said. Typhoon Rai slightly weakened after slamming ashore Thursday on the country’s southeastern coast but still packed destructive and deadly winds of 150 kilometers (93 miles) per hour and gusts of up to 205 (127 mph). Meteorologists said it was moving away into the South China Sea on Friday. Officials were assessing the damage and casualties wrought by one of the strongest typhoons to hit the country in recent years but said efforts were hampered by widespread power outages, downed communications, and roads clogged with fallen trees and debris. Witnesses described ferocious winds that ripped off roofs and forced down trees. “I have never experienced such ferocity of the wind in my life and we were not …