The ferocious wildfires turning areas of Los Angeles into raging infernos are being fueled by “hurricane force” Santa Ana winds that have already prompted the evacuation of tens of thousands of people and are rapidly destroying homes.

The winds are common in California in the colder months, but they can sometimes help spread dangerous wildfires.

Santa Ana winds are synonymous with southern California weather. They can happen any time of the year but are more common during the cold months. They happen when a ridge of high-pressure forms over the Great Basin and an upper-level low forms near the desert southwest.