Heavy rain and strong winds are still sweeping the Bay Area Saturday, prompting flood watches, wind advisories and power outages across the region.

The Bay Area was soaked by a powerful storm system overnight into Saturday morning, causing flooding and even triggering what is reported to be the first-ever tornado warning in San Francisco, officials said.

Heavy Rain: Prolonged heavy rain can saturate the ground, making it easier for trees to uproot. If trees fall onto power lines or substations, this can result in widespread outages. Flooding: Areas experiencing flooding may have electrical infrastructure compromised, which can also lead to power disruptions.