Santa Ana winds whipping up severe firestorms across southern California

Figure 1 – Image courtesy of the Los Angeles Daily News

High pressure of around 1040 hPa to the north over Vancouver Island, and low pressure over the equatorial eastern Pacific to the south has combined to produce ideal conditions for the Santa Ana wind to whip up fierce fire storms across southern California in the last day or so. As the Wikipedia article points out the Santa Ana is a katabatic wind rather than a föhn winds, and its extremely dry as it blows down from the Sierra Nevada mountains.

Figure 2