Heavy rain is the biggest risk factor, because the burn scars over this area have very weak soils and foundations. Light rain might not affect much, but if the rain is heavy enough and persists for long enough, debris flows will be possible.

A winter storm warning and wind advisory is in effect in Southern California's mountains and foothills, and a flood watch is pending in the recent wildfire areas across the Southland. According to AccuWeather, the rainfall is imminent, with the first drops expected in Los Angeles and San Diego Counties at about 9 p.m. Saturday.

The National Weather Service said there is a 15-25% chance of thunderstorms across the region, which could bring periods of heavy rainfall that could overwhelm the burn-scar areas. There is also a threat of some small hail and locally high wind gusts. “This is not all-day rain. It’ll be a lot of on-and-off showers throughout the day,” FOX Weather Meteorologist Ari Sarsalari said. “They’re a little bit hit or miss, but very high likelihood that you’re going to get wet at some point.”