More than 20,000 PECO customers remain without power in the wake of powerful thunderstorms that swept through the region Tuesday night. According to PECO, 528 outage sites are impacting more than 18,000 customers in Chester County alone.

Restoration times vary -- some noting power will be restored by 11 p.m. Thursday, but many sites are still awaiting an evaluation, according to PECO.

There are also more than 1,000 customers without power in Montgomery County and scattered outages in Bucks and Delaware counties and South Jersey.