The tornado never touched down in San Francisco. But the conditions in the atmosphere with wind speed and direction were right, said Brian Garcia, warning coordination meteorologist for National Weather Service in the Bay Area. “San Francisco got lucky,” he said.

Flooding and power outages in SF - even a tornado warning as inclement weather hits the Bay Area. Steve Saldivar. More Videos

San Francisco experienced its first-ever tornado warning early Saturday, stunning residents as a powerful storm swept through the Bay Area, bringing heavy rain and winds. The warning prompted a flood of social media posts from residents startled awake by emergency alerts.