This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.The first in a new series of winter storms that will hammer Southern California through next week is expected to arrive Friday night, bringing periods of heavy rain to recent burn areas that officials worry could unleash rockslides and debris flows. The Pacific system is expected to drop half an inch to an inch of rain across much of Los Angeles and Orange counties through Saturday. Ventura County could see a bit more — 1 to 3 inches — before the storm moves out of the area. The National Weather Service predicts the heaviest period of rain will begin about midnight and last through 7 a.m. Saturday. There is also a chance of thunderstorms. Peak rain rates of half an inch to three-quarters of an inch per hour are expected over the Woolsey and Hill fire burn scars, which could trigger mudslides, said Kristen Stewart, a weather service meteorologist in Oxnard. The key factor in forecasting debris flows is the intensity of the precipitation as it falls on an area. The amount of rain necessary to start mud and debris flowing varies based on how recently the area burned, the topography and other factors. Read the full story on LATimes.com.