Snow shut down a key interstate north of Los Angeles for hours on Monday while weekend downpours doused wildfires across Southern California in the first significant storm of

Much-needed rain has begun to fall over Southern California, bringing relief to the drought-stricken region but also the threat of toxic runoff.

After historic winter firestorms in Southern California, a late weekend bout of rain brought conditions helpful for easing flames - though it also brought some risk of concerning debris flows through recently burned areas.