For the first time in recorded history, downtown San Francisco was issued a tornado warning on Saturday as severe storm conditions swept through the city, prompting local authorities to warn residents of the rare threat.

Less than two weeks after a tsunami warning, residents were jolted awake before 6 a.m. to consider a new potential disaster scenario.

A strong atmospheric river drenched northern California with heavy rains and damaging wind gusts Saturday, leaving well over 200,000 without power in the state.