Winds and Gusts during Strong Santa Ana Events

The "Santa Ana" winds occur in Southern California during the September-May time frame, bringing low humidities across the area and strong winds at favored locations, which include some mountain gaps and on particular slopes. The exceptionally strong event of late October 2007, which sparked and/or spread numerous fires across the region, is compared to more recent events using a numerical model verified against a very dense, limited-area network (mesonet) that has been recently deployed in San Diego County. The focus is placed on the spatial and temporal structure of the winds within the lowest two kilometers above the ground within the mesonet, along with an attempt to gauge winds and gusts occurring during and after the onset of October 2007's Witch fire, which became one of the largest wildfires in California history. A mechanism for generating particularly large gusts over the Witch fire initiation site is also identified.

References:

Cao, Y., and Fovell, R. G. (2016), Downslope windstorms of San Diego County. Part I: A Case Study. Mon. Wea. Rev., 144, 529-552. http://dx.doi.org/10.1175/MWR-D-15-0147.1

Fovell, R. G., and Y. Cao (2016), The Santa Ana winds of Southern California: Winds, gusts, and the 2007 Witch fire. Wind and Structures, conditionally accepted.