Atmospheric River Hammers SoCal With 'Historic Rainfall': See County-By-County Tallies

A powerful atmospheric storm system that pummeled Southern California over the weekend, forcing evacuations and causing widespread damage, continued to pose a threat Monday morning.

Thus far, the storm has killed at least six people statewide and has shattered rain records in the Southland.

Powerful winds, flooding across roadways, as well as mudslides near recent burn scars, "will be common due to this storm being on the heels of the historic rainfall we received just a few days ago," the National Weather Service warned early Monday.

"There is a 20 to 30 percent chance of reaching debris flow thresholds (15, 30, 60-minute durations) in the recent burn scars," forecasters said.

Officials urged residents to avoid travel during the peak of the storm Monday afternoon and evening and to have multiple ways of receiving weather warnings and alerts from local officials, according to an early-morning forecast discussion.

Moderate to heavy rain is expected ahead of a cold front moving into most of Southern California Monday evening, forecasters said. There is also a 10% to 20% chance of thunderstorms through early Tuesday evening.

In fire-scarred areas of Los Angeles County, forecasters expect peak rainfall rates of 0.25 to 0.50 inches per hour, with isolated rates above 0.80 inch likely during thunderstorms.

In San Diego County, rainfall totals are expected to range from 0.50 to 0.75 inch from the coast to the mountains, with 1 to 1.6 inches possible on south- and southwest-facing coastal slopes. Desert areas could see 0.10 to 0.30 inch, with less than 0.10 inch in the lower deserts, the NWS said.

Rainfall in Riverside County and across the Inland Empire is expected to range from 0.50 to 0.75 inches from the valleys to the mountains, with 1 to 1.6 inches possible along south- and southwest-facing slopes, according to the NWS.

Desert areas could see 0.10 to 0.30 inches, with slightly higher totals possible.

Over the past five days, cities have seen significant rainfall. Here are the rainfall totals across SoCal, according to the NWS:

Los Angeles County:

• Monte Nido FS: 2.44 inches
• Culver City: 1.08 inches
• Beverly Hills: 1.26 inches
• Hollywood Reservoir: 1.82 inches
• Downtown Los Angeles: 1.68 inches
• Agoura: 2.83 inches
• Chatsworth Reservoir: 2.61 inches
• Canoga Park: 1.89 inches
• Sepulveda Canyon at Mulholland: 1.80 inches
• L.A. City College: 2.20 inches
• Eagle Rock Reservoir: 2.74 inches
• East Pasadena: 2.45 inches
• Mount Baldy FS: 3.99 inches
• Lancaster: 0.59 inches

Orange County

• Brea Olinda: 2.72 inches
• Brea 2W: 3.15 inches
• Orange County Reservoir: 3.09 inches
• Fullerton Airport: 3.62 inches
• Fullerton Dam: 3.16 inches
• Anaheim Barber City: 2.92 inches
• Costa Mesa: 2.64 inches
• Anaheim Hills: 3.51 inches
• Alameda Storm Channel: 3.03 inches

Riverside County

• Eastvale: 2 inches
• Riverside: 1.42 inches
• Moreno Valley West: 1.81 inches
• Beaumont: 1.65 inches
• Hemet: 1.18 inches
• Perris: 1.77 inches
• Lake Elsinore: 1.67 inches
• Murrieta: 2.09 inches
• Temecula: 1.50 inches
• Palm Springs: 1.01 inches

San Diego County:

• Carlsbad: 2.20 inches
• Encinitas: 1.25 inches
• Oceanside: 2.64 inches
• Chula Vista: 0.89 inches
• Santee: 1.32 inches

Damage from the weekend’s heavy rains could also contribute to hazards through midweek. The weather service issued a wind advisory for most mountain and inland areas.

“The wet grounds will also bring an increased risk of downed trees with strong winds associated with any stronger winds,” forecasters warned.

A “secondary peak” of thunderstorms could develop Tuesday afternoon across the region.

As the storm exits Wednesday, slightly warmer temperatures are expected — but another system arriving Thursday could bring additional rain, officials said.

“Wednesday will offer a brief respite from the rain with warmer temperatures,” the NWS said.

Forecasters in San Diego said the next storm system is expected Thursday and Friday, “though details with this system still remain uncertain.”

While several people lost their lives on the Central Coast and in Northern California during last week's storm, four people died off the coast of San Diego Friday night after their boat capsized in stormy seas.

The wooden boat was believed to have been ferrying migrants toward the U.S. from Mexico, the Coast Guard said Saturday.

Four others were injured in the incident.

READ MORE: 4 Dead, 4 Injured After Boat Capsizes Off Imperial Beach Coast: Coast Guard

Meanwhile, authorities have recovered the body of a 7-year-old girl who was swept into the ocean amid high surf in Big Sur. Her father, 39-year-old Yuji Hu, died trying to save her on Friday.