Santa Ana winds are the most common type of wind that drives wildfires in California. These dry, warm winds blow from the inland deserts toward the coast, causing low humidity levels and drying out vegetation, making it more susceptible to ignition and rapid spread of wildfires.
Most of the damage from a firewhirl, which is not a true tornado, is fire damage, from structures and vegetation in the path beng burned. Winds in a firewhirl generally do not exceed 100 mph, equivalent to an EF1 tornado, which can cause severa roof damage and destroy some weaker structures. The primary threat is in the potential to spread fire to a new location.