On Monday evening, a line of storms with damaging wind gusts, large hail, and heavy rain swept through the Mid-Atlantic region. Hundreds of thousands of customers are without power, and a large number of flight disruptions have been reported at major airports. 

Over 40 million people from Tennessee to New York are currently under a tornado watch.

Ryan Maue, a meteorologist and former NOAA chief scientist, tweeted, "Heavy duty squall line bowing into Philadelphia in next 30-minutes with gusty winds, embedded tornado." 

Nearly 700,000 customers are without power across nine states, according to Poweroutage.US. 

More than 1,200 flights are delayed and 350 canceled, with the bulk of the disruptions at Mid-Alantic airports. 

Chaos across Mid-Alantic and Northeast. 

*Developing...