Since the first flames sparked in the Santa Ana winds on January 7, at least 16 have been confirmed dead, 12,000 structures have been destroyed, and over 150,000 residents have been ordered to leave their homes.

Santa Ana winds occur when air flows west from a region of high pressure over the dry Great Basin to lower pressure off the California coast, According to Accuweather. As that cool interior air flows over and through mountain passes, it accelerates, sinks and compresses.

At least five wildfires are ravaging Southern California, and the three largest have already killed at least five people, burned tens of thousands of acres and prompted the evacuation of an estimated 179,