The Santa Ana winds occur when there is high pressure to the east, in the Great Basin, and a low-pressure system off the coast. Air masses move from high pressure to low pressure, and the more extreme ...

though the NWS did not issue any fire weather watches as of Thursday. Even before Santa Ana winds ramped up, a brush fire sparked in the mountain range where the wind advisory would later take effect.

Jon Keeley, University of California, Los Angeles (THE CONVERSATION) Powerful Santa Ana ... the winds get to the point where the Eaton Fire broke out in Altadena on Jan. 7, it’s not uncommon ...