As per reports, the first of two atmospheric rivers is currently affecting a significant portion of California, bringing heavy snowfall at high elevations, strong winds and rainfall across the region.

Over 20 million people are under flood alerts as storms threaten flash flooding in central and Southern California, including cities like Los Angeles, San Diego, Sacramento, San Francisco, San Jose, and Oakland. The flood threat is expected to last into Friday (02 February) morning.

• Evacuation warnings have been issued for some areas of San Diego due to the storm on Thursday and Friday (01 and 02 February). The mayor of San Diego issued a voluntary warning for residents of flood-prone communities, urging them to prepare for possible evacuation. Areas near Fashion Valley along the San Diego River are expected to surpass flood stage by evening hours on Thursday (01 February).
• Winter weather conditions are anticipated in northern areas, with snowfall expected at lower elevations across Northern California and the Sierra Nevada, prompting the California Governor’s Office of Emergency Services to activate its operations center.
• A winter storm warning is in effect for the mountains of Los Angeles, Riverside, and San Bernardino counties through late Thursday (01 February). The highest elevations may receive up to 18 inches of snow, creating difficult travel conditions, especially along the 05 Freeway corridor. Strong winds, with gusts exceeding 60 miles per hour, are expected, posing risks of downed trees and potential power outages. The southern Sierra is forecast to experience heavy snowfall, with up to four feet possible, leading to concerns about flooding and mudslides in the foothills where precipitation does not freeze.
• High surf conditions with waves up to 12 feet are anticipated along the beaches of Ventura, Los Angeles, Orange, and San Diego counties, accompanied by dangerous rip currents.
• South and east of Los Angeles, including parts of San Bernardino, Riverside, Orange counties, remain under a flood watch through late Thursday (02 February). Excessive rainfall may cause ponding on roadways, flooding in low-lying areas, and along some waterways.
• Winds across Southern California could reach up to 40 miles per hour, causing potential delays at Los Angeles International Airport, downed trees, and power outages.
• A second atmospheric river storm is expected to impact the region starting Sunday (04 February), potentially bringing significant rainfall and raising concerns about damaging flooding. The system is forecast to move at a slower pace, increasing the risk of extended rainfall.