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'Biggest storm of winter' to unleash flooding rain in California at week’s end

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A new train of storms has arrived along the Pacific coast, and a potent one is set to hit California hard with heavy rain, mountain snow and strong winds during the latter part of this week.

The first storm will focus on areas from Northern California to Washington into Thursday. The second storm in the series will focus most of its moisture on Southern California from Thursday night to Saturday.

"The late-week storm has the potential to be the biggest of the winter in terms of rainfall and impact to much of Southern California," according to AccuWeather Meteorologist Jim Andrews.

Static California Storm Thu to Sat

The storm will bring enough rain and excess runoff to cause flash flooding, which can cause major delays for motorists. Along with the heavy rain will be the potential for mudslides in some neighborhoods, especially in recent burn scar locations.

"We expect 3 to 6 inches of rain to fall in the lowlands along the coast and over the Los Angeles basin," according to AccuWeather Senior Meteorologist Ken Clark. "From 6 to 12 inches of rain is likely below snow levels in the mountains, especially along the south-facing slopes."

In the Los Angeles area, much of this rain may fall in 24 hours from Friday morning through Friday night.

AP image DT L.A. Feb 6 2017

Pedestrians cross a rainy street in downtown Los Angeles on Monday, Feb. 6, 2017. From Dec. 1, 2016, through Feb. 14, 2017, nearly 15 inches of rain has fallen on Los Angeles, which is about twice that of average for the period. (AP Photo/Nick Ut)

That much rain in such a short period of time could lead to some roads becoming impassable for a while.

The combination of heavy rain, a low cloud ceiling and gusty winds will also lead to airline delays.

As the ground becomes soggy again, gusty winds will raise the risk of fallen trees and sporadic power outages.

Snow levels will remain well above the passes in Southern California. However, those venturing over Donner Pass are likely to encounter slippery conditions. The ski resorts in the Sierra Nevada will likely receive 1 to 2 feet of snow fro the storm later this week.

In the wake of the big rain through Friday night, spottier showers will continue to dampen the region on Saturday and Saturday night.

Little to no rain may reach Southern California during the period from Sunday through next week.

Another storm will roll ashore from the Pacific during Sunday night. However, most effects from the storm will be focused from Northern California to Washington during the first half of next week.

As a result of the ongoing storms, more challenges are ahead for crews, officials residents in the Oroville, California, area. Damage to the spillway at the Oroville Dam forced evacuations earlier this week.

The rainfall to end this week will take another big chunk out of the drought over Southern California.

Total rainfall since Dec. 1 over much of Southern California has ranged from 1.5 to 2.5 times that of average.

While less than 1 percent of the state remained in extreme drought as of last week, much of the region remained in moderate to severe long-term drought, according to the United States Drought Monitor.