SANTA CLARITA, Calif. – Southern California is forecast to experience potentially damaging Santa Ana winds through midweek, fueling a dangerous fire threat for the mountains and valleys of Los Angeles and San Diego counties.Santa Ana winds blow from the Santa Ana Mountains in Southern California, bringing in hot, dry air from east of the mountains. They can occur at any time of year but are more common during cooler weather from fall through winter.These strong winds are forecast to have the biggest impacts on Los Angeles and Ventura counties beginning Monday night through Wednesday evening.Many of the windier corridors in these counties could experience damaging wind gusts, which could cause downed trees and powerlines, along with power outages. Santa Ana winds can often increase the fire danger for Southern California, and forecasters are expecting that to be the case this week.The National Weather Service Los Angeles has issued a Particularly Dangerous Situation (PDS) Fire Weather Warning for much of the Santa Ana wind corridor of Los Angeles and Ventura Counties through Tuesday. The PDS Warning extends through Wednesday for the Susana Mountains. “This event has the potential to be as strong as the November 5th-6th Santa Ana event that led to the Mountain Fire,” the NWS Los Angeles warned. “Prepare for fire weather by ensuring you have defensible space and creating a plan in case of evacuation. Any new fire will grow rapidly, likely exhibiting extreme fire behavior.”The Mountain Fire in Ventura County quickly grew to nearly 20,000 acres, destroying nearly 250 homes and structures. The greatest fire threat will unfold late Monday night into Wednesday. NOAA’s Storm Prediction Center is forecasting critical fire weather conditions for Santa Clarita, Riverside, San Bernardino, Ontario, Fontana, Palmdale, Lancaster, Thousand Oaks and Simi Valley.Forecasters with the National Weather Service said the fire threat will increase across Los Angeles and Ventura counties through Wednesday, where humidity in the single digits could coincide with damaging winds between 60 and 80 mph. A Fire Weather Warning is in place for the Los Angeles and Ventura County mountains and valleys through Wednesday night. A warning is also in place for the Ventura County coast and Malibu through Wednesday afternoon.SATELLITE IMAGERY REVEALS SCOPE OF MOUNTAIN FIRE DEVASTATION IN CALIFORNIAThe San Luis Obispo County mountains face a Fire Weather Watch until Tuesday night. Santa Clarita and Temecula could see wind gusts around 50 mph.With the forecast conditions, the Los Angeles Fire Department (LAFD) is asking people to refrain from using spark-creating equipment outdoors this week. “If you must, ensure you have adequate water on hand to extinguish any sparks before it’s too late,” LAFD wrote on Facebook. A Fire Weather Warning is also in place from Monday morning to Wednesday morning for all San Diego County mountain and valley areas and the Inland Empire.Wind gusts could reach up to 70 mph on Tuesday in the mountains, and relative humidity will be between 5% and 10%. Winds will decrease by Wednesday afternoon. However, the humidity will stay extremely low.