ROCHESTER, N.Y. (AP) _ About 20,000 homes and businesses across upstate New York are without electricity after powerful thunderstorms moved through the region, knocking down utility lines and trees.

RG&E reports about 4,800 customers still without power in the Rochester area Wednesday morning after high winds and heavy rain hammered Monroe County Tuesday night. About 9,000 customers lost power during the storm.

National Grid reports more than 15,000 outages among customers from western New York to the eastern Adirondacks. More than 6,000 of the outages are reported in the Mohawk Valley. The utility says electricity service should be restored for most customers at late Wednesday afternoon.