More than 10,000 Penelec customers in McKean, Potter and Elk counties alone are without power as of 9:30 a.m.
In Cameron, Tioga, Warren, Forest and Jefferson counties more than 7,300 customers are without power.
Most of the state -- except the Philadelphia area and a small portion of the east/central portion -- has power outages to some extent.
Governor Andrew Cuomo has declared a state of emergency for Chemung County, allowing New York State to better coordinate and respond with local governments to the widespread damage caused by a line of severe thunderstorms that caused possible tornadoes, winds in excess of 60 miles per hours, and hail over one inch in diameter.
A tornado was confirmed in Elmira.