The Bay Area is gearing up for a week of significant climate shifts, with cold temperatures making way for a potent atmospheric river expected to bring substantial rain and strong wind later in the week. The National Weather Service in San Francisco has issued Freeze Warnings and Frost Advisories for much of the region through Wednesday morning, advising residents to protect the "4 Ps from the cold: People, Pets, Plants and Pipes."

As temperatures drop to record lows potentially, the dry cold snap is set to be followed by light rain starting late Tuesday, according to NWS San Francisco. Wednesday evening will increase precipitation intensity as a stronger weather front approaches, carrying urban, small stream flooding risks and shallow landslides. Strong southwesterly winds, reaching up to 40 mph in the lowlands and up to 60 mph in the mountains, are anticipated to cause damage to trees and potential power outages.

Concerns over heavy rainfall and hazardous marine conditions have also been highlighted, with the National Weather Service's Area Forecast Discussion stating, "Nearly all areas are expected to get at least 2", with up to 8" in the Santa Cruz and Santa Lucia mountains." This volume of rainfall is expected to lead to various types of flooding and the possibility of thunderstorms from Thursday night through Friday morning.

Those in the Bay Area can stay informed on the shifting conditions by following updates from the National Weather Service and planning accordingly for this bout of weather, which ties in colder-than-average temperatures with a significant warm moisture surge by late in the week. For a detailed look at the evolving forecast, including the possibilities of drizzle leading into heavier rain bands, check the NWS detailed 7-day forecast for San Francisco.