Topline: Several days of rain are forecast to kick off Sunday as a series of storms rolls through, one after another. It’ll be one of the coldest weather systems we’ve seen so far this year, bringing a whole lot of much-needed snow to California, according to the National Weather Service.

Rainfall timing: The heaviest rain is expected to fall on Monday, with 2 to 4 inches possible in the Los Angeles area. (Long Beach is expected to be on the lower end of that range.) Then, there will be on-and-off precipitation for the remainder of the week, though there’s a lot of uncertainty about exactly when you’ll need to have your umbrella handy. Thunderstorms could bring isolated pockets of heavy rainfall, potentially causing debris flows. Things should dry out by late next week.

About the snow: The coldest part of the weather system is expected to arrive on Tuesday, dropping snow levels to around 4,000 feet in Southern California. Two to 3 feet of snow could fall at higher elevations throughout the week, including at ski resorts. We could see anywhere from 4 to 6 feet of snow along the crest of the Sierra Nevada, from Mammoth past Lake Tahoe, along the crest of the Sierra. That’s all good news for California’s snowpack, which is well below average for this time of year.