By Barbara Goldberg
NEW YORK (Reuters) - Pounding rains from Tropical Storm Lee on Wednesday drenched the already soggy East, where resurging rivers and downed trees closed roadways and railways, snarling the morning commute.
Heavy rainfall, predicted through Thursday across the Appalachians and Mid-Atlantic states, was expected to amount to an additional 4 to 8 inches, with up to 10 possible in some areas, according to the National Weather Service.
"These rains may cause life threatening flash floods and mudslides," the NWS warned in a statement on its website.
The areas identified most at risk for flooding were the Appalachians and interior Northeast, particularly the municipalities of Altoona and Johnstown, Pennsylvania, and Elkins, West Virginia, according to AccuWeather.com meteorologists.
Tropical moisture and gusts streaming up from the Atlantic Ocean also threatened to cause tornadoes.
"A few isolated storms could show a tendency to rotate, threatening to create a tornado," said meteorologist Bill Deger on AccuWeather.com.
The government of Maryland forecast thunderstorms Wednesday and Thursday, and a flash flood watch was in effect with a coastal flood watch expected in the evening.
Resurging rivers from Northhampton, Massachusetts, to Philadelphia, already filled from Hurricane Irene, flooded their banks and shut down sections of major roadways just before the morning commute.
Near New York City alone, authorities said they closed down parts of the Hutchinson River Parkway, Saw Mill River Parkway, Bronx River Parkway and Sprain Brook Parkway, and none was expected to open quickly.
In Philadelphia, one of the main commuter routes into Center City, Kelly Drive, was closed because of flooding from the Schuylkill River.
Amtrak also suspended service on one of the busiest commuter rail lines in the Philadelphia region, the Southeast Pennsylvania Transit Authority line from the suburbs of Paoli and Thorndale.
"Several large trees have fallen onto the tracks and have also damaged the overhead electrical system that powers the trains," an Amtrak statement said.
In Massachusetts, the Mill River in Northampton jumped to flood stage at above 11 feet by mid-morning, flooding roads and affecting some low-lying homes and businesses in several parts of town adjacent to the river, according to the weather service's Advanced Hydrologic Prediction Service.
The Federal Aviation Administration reported delays at Philadelphia International, Newark International, John F. Kennedy International, La Guardia, and General Edward Lawrence Logan International in Boston due to the weather.
The worst wait was reported at La Guardia Wednesday morning, with some arriving flights delayed an average of one hour and 22 minutes.
(Additional reporting by Dave Warner in Philadelphia and Molly O'Toole in Washington; Editing by Jerry Norton)