SoCal residents, brace yourselves for a wild weather week ahead. The National Weather Service San Diego has forecasted a series of low pressure systems set to unleash rain and mountain snow across Southern California, starting Monday and ramping up into midweek. Temperatures are expected to remain in the 60s in coastal and valley areas. At the same time, the mountains will see chillier conditions, with highs in the 40s and 50s, and the lower deserts staying comfortably in the mid 70s.