Bomb Cyclone Possible As Deadly Storm Conditions Are Expected To Slam SoCal Over Christmas

The Southland is in for one of the wettest Christmas weeks in years following a dry month as an atmospheric river, dubbed a pineapple express storm, barrels toward the region.

And the storm forecast just "keeps getting worse," according to KTLA weather anchor Mark Kriski.

Major travel disruptions, mudslides, flooding and other safety hazards are expected to come at one of the busiest travel times of the year, the National Weather Service said, urging residents to prepare.

Rain and gusty winds are expected from Tuesday through Thursday with the heaviest day of rain forecast for Wednesday, Christmas Eve.

In downtown Los Angeles, there's an 80 percent chance two inches of rain or more will fall from Tuesday through Christmas day. The last time downtown got that much rain over those two days was in 1971, the Los Angeles Times reported.

"While no rain has fallen in L.A. so far this month, a stormy pattern from Tuesday to Saturday may bring two to four times the average rainfall of 2.48 inches for December," according to a Monday report from AccuWeather.

Throughout San Diego, LA, Orange counties and the Inland Empire — between 4 and 8 inches of rain are expected between Tuesday and Saturday, according to AccuWeather.

The Christmas storm is the second atmospheric river to hit California this week. The first one drenched Northern and Central California, killing at least one person. The storm missed SoCal.

Forecasters explained that the system will materialize in the Golden State after traveling from Hawaii, drawing moisture from the Pacific, which will meld with a trough of low pressure coming out of the Gulf of Alaska.

The National Weather Service says there is a 90 percent chance of high to very high rainfall totals across the Southland. Such high rainfall warnings are rare for California, yet they account for a third of all storm deaths and 80 percent of all flood damage, CNN reported.

"Just as with the first atmospheric river that was largely confined to Northern California, rain will be drenching, leading to rapid urban flooding and flooding of small streams and short-run rivers, along with mudslides, washouts and the potential for hillside slides in Southern California," according to AccuWeather.

What's more, the storm could rapidly strengthen, forecasters said, with widespread strong winds between 40 and 60 mph, with gusts of up to 80 mph, expected across many areas.

"The storm providing the atmospheric rivers has the potential to become a bomb cyclone off the California coast," said AccuWeather Meteorologist Brandon Buckingham.

Heavy rainfall will result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations this week (Dec. 22-26) across portions of California. Mud and debris flows will be possible across foothill and mountain areas, including recent burn scars.… pic.twitter.com/LaaySJrQtM
— National Weather Service (@NWS) December" class="redactor-linkify-object">https://twitter.com/NWS/status... 22, 2025

Light showers are expected to begin across the region on Tuesday, approaching from the southwest, around mid-afternoon to early evening. On Wednesday, "much heavier" rain is expected. After a brief reprieve from the rain and winds on Christmas Eve, a "second burst" of rain and wind is expected Christmas Day, according to the NWS.

"Initially it was thought that the Christmas day rain would be fairly benign, but more recent models are indicating a similarly strong low level jet of 60-70kt returning that morning," the weather service said.

A High Wind Watch and a Flood Watch will be in effect across many areas throughout the week.

The NWS is advising SoCal prepare for the following potential hazards:

• Downed trees and power lines
• Dangerous sea conditions for all vessel types
• Coastal flooding
• Streams and river flooding
• Flooding over curbs that could affect homes and businesses
• Flooded freeways
• Mudslides, especially in burn scars
• Water rescues
• Power outages

Residents are also urged to guard areas of their properties with sandbags, which can usually be found at fire stations and municipal centers. Check your city's website to find out where to get and fill sandbags.

The National Weather Service said another storm system appears to be developing in the Pacific Northwest and could track into Southern California shortly after Christmas, though its timing and strength remain uncertain.