RICHMOND, Va. (AP) _ A severe thunderstorm with heavy rains downed trees and knocked out power to more than 160,000 customers in Virginia. The damage and outages prompted Richmond and Henrico County public schools to cancel classes Friday. National Weather Service Meteorologist Bryan Jackson says the weather service received eye-witnesses reports of a tornado near Berryville in Clarke County about 6 p.m. Thursday. He says storm surveys will be conducted Friday to determine whether there was a tornado. Jackson says the weather service received reports of large hail up to the size of baseballs. Dulles International Airport received 2.82 inches of rain Thursday, breaking a 1974 record of 1.78 inches. Jackson says data show that 2 inches fell there in just 20 minutes.