Annually, the onset of the fall and winter seasons brings the highest chance for Southern California’s famed Santa Ana winds.
Typically Santa Ana air mass conditions are brought on by high pressure inland and lower pressure off the Pacific Coast which brings very hot and dry weather along with strong, down-slope winds. In the past, the critical fire weather conditions that accompany Santa Ana winds turn the typically dry chaparral of Southern California into explosive fuel. Some of the country’s costliest fires in history have taken place in these conditions.
Interestingly, this year meteorologists are expecting an El Niño cycle to begin affecting the area with rains by November. In the meantime, as the tropical air mass that has brought this summer’s rain gives way to autumn’s Pacific air mass, a few Santa Ana events should precede the El Nino’s wetting effect.