Containing wildfires—never mind extinguishing them—in parched and windy conditions can be monstrously difficult. Dry vegetation is rocket fuel for blazes and wind both feeds the flames and spreads the embers. “The winds are like pointing an air blower at a fireplace,” says Gershunov, “except it’s not contained and it’s on a much larger scale.”

The first significant rainfall in several months will spread across Southern California this weekend, giving a badly needed sip of water to an area parched by drought and devastated by multiple raging wildfires.