Update: Severe thunderstorm warning previously issued for Chester County will expire at 4:15 p.m.

The warning was in place for Chester County.

"The storm which prompted the warning has weakened below severe limits, and no longer poses an immediate threat to life or property. Therefore, the warning will be allowed to expire. However heavy rain is still possible with this thunderstorm. A Severe Thunderstorm Watch remains in effect until 8 p.m. for southeastern Pennsylvania," adds the National Weather Service.

Lightning on the horizon: Expert safety measures for thunderstorms

Lightning strikes the United States approximately 25 million times each year, mostly during the summer. Lightning claims the lives of about 20 people annually, according to the weather service. The risk of lightning-related incidents escalates as thunderstorms draw near, reaching its peak when the storm directly l