Biggest Christmas storm in years set to hit SoCal: A timeline for the week

A Pineapple Express storm could deliver one of Southern California’s stormiest Christmases in recent memory.

The basics

• The storm is expected to deliver 4 to 8 inches of rain between Tuesday and Saturday throughout most of Los Angeles County, Orange County and the Inland Empire.
• The High Desert could see 2 to 3 inches of rain. But the most precipitation — 6 to 12 inches — is expected to fall over parts of Southern California’s mountain ranges, which could trigger mudslides and debris flows in recent burn scars.
• Between Tuesday and Thursday, numerous areas have a high chance of seeing 3 or more inches of rain. There’s a 77% chance of that occurring in Anaheim and Yorba Linda, a 74% chance in Santa Ana, a 73% chance in Ontario, a 71% chance in Mission Viejo, a 69% chance in Irvine, a 68% chance in Chino, a 65% chance in Laguna Niguel and a 60% chance in San Clemente.
• There’s an 80% chance downtown Los Angeles will get 2 or more inches of rain from Tuesday through Christmas Day. The last time downtown got 2 or more inches of rain over Christmas Eve and Christmas Day was in 1971.

Timing

Tuesday: Rain begins in the region, getting worse through the day and night.

Wednesday: The latest weather models show the region’s heaviest rainfall totals — from a half an inch to 1 inch per hour — could occur between midnight Tuesday and noon Wednesday.

Thursday: Rain continues on Christmas Day, but with less intensity in the afternoon and evening.

Friday: Some rain will still be possible.