(CNN) About 1,250 lightning strikes were recorded in western Washington state during a storm that caused widespread power outages Saturday night, the National Weather Service said.

A strong line of thunderstorms developed over western Washington, bringing frequent lightning, heavy rains, flooding and hail to the Puget Sound region, according to the National Weather Service's office in Seattle.

The 1,250 lightning strikes were between 6 p.m. and 9 p.m. local time, it said. Of those, 200 were recorded in the Seattle metro area from 8 p.m. to 9 p.m.

Lightning occurs when ice particles within a cloud interact with each other through collision, causing the particles to fracture and break apart, according to NASA. The intense heat of the lightning generates a sound called thunder that is transmitted through the air at the speed of sound, it added.

Lightning and thunder happen at the same time but since light travels faster than sound, the flash of lightning is seen sooner than thunder is heard.

Read More