Rain not done here yet: Up to 5 inches expected in many areas; some Md. residents are urged to leave.

Byline: Michael Dresser and Frank D. Roylance

Jun. 28--Torrential rain from a new storm out of the south lashed an already saturated Maryland overnight, as emergency officials braced for what could be a scene of widespread damage and disruption this morning. Forecasters were warning of an additional 3 to 5 inches of rain last night and today - with downpours of up to 8 inches in especially unlucky locations. "It's not good news," said Bob Oravec, lead forecaster at the National Hydrometeorological Prediction Center in Camp Springs. Streams already at flood stage "are not going to be helped by additional runoff," he said. While there were no confirmed deaths yesterday from the rain and flooding, rescue workers were searching for two missing teenage boys after the father of one of them found a bicycle and clothing by a bridge at Little Pipe Creek near the border of Frederick and Carroll counties, state police said. An apparent tornado touched down near Chaptico in St. Mary's County shortly after 6 p.m., destroying two barns and damaging several homes and an automotive repair shop, said Tim Cameron, the county's director of public safety. Another was sighted near Mechanicsville. No injuries were reported, he said. Around the state, local officials were urging residents of low-lying areas to move to shelters. The Susquehanna River was expected to crest above major flood levels in Harrisburg, Pa., tomorrow - with potentially devastating consequences for Maryland towns downstream and the…