Strong storms knocked out power this week to customers from Oklahoma to Connecticut. As they waited on Sunday for the lights to come back on, the forecast called for more severe weather.

PJM ​said ​it was ​under a federal alert to cut electricity consumption. It serves 67 million people ⁠in the Mid-Atlantic, South and Washington, D.C., area.

Around 21,000 homes remain without power days after weekend storms lashed central Pennsylvania. PPL reported around 21,000 customers were without power in the Harrisburg area and eastern Cumberland County,

DTE said crews had been working in 'extremely difficult' conditions.