A first-ever tornado warning was issued for San Francisco County earl…

A first-ever tornado warning was issued for San Francisco County early Saturday as thunderstorms and wind gusts of up to 80 mph swept through the region, officials said.

“Take shelter now in a basement or an interior room on the lowest floor of a sturdy building,” a National Weather Service advisory said on social media. Parts of San Mateo County were also included.

More than 1 million…