Extreme winds are fueling horrific fires across Southern California, and one particular weather phenomenon called mountain waves is threatening to spread the flames even more.
Santa Ana winds—the strong, dry winds that hit Southern California during this time of year—are especially extreme, reaching as high as 100 mph around Los Angeles. When those winds hit the San Gabriel Mountains, they can cause mountain waves.
Mountain waves are “these large scale patterns that occur when strong winds hit mountain ranges at a perpendicular angle,” says Devin Black, a general forecaster with the National Weather Service in Oxnard, California, a city west of Los Angeles. That angle then forces the winds to rise over the mountain, and then swoop........