Snow in August?

Strong thunderstorms are roaring through parts of the region, causing rush-hour headaches in Montgomery County.

A storm knocked out power to traffic lights in West Norriton, and fallen trees blocked roads in Norristown and Lower Merion Township.

Officially, the National Weather Service reported a 60 m.p.h. gust at Philadelphia International Airport, where the 6 p.m. observation read: "Heavy rain with thunder, small hail, and/or snow pellets.

The weather service has posted a flood advisory for parts of Chester, Delaware, and Montgomery Counties, and Philadelphia.

A severe-thunderstorm warning is in effect from Chester County into South Jersey.