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Abstract

Coastal Santa Barbara County (SB) is among the most exposed communities to wildfire hazards in southern California. The Santa Ynez Mountains (SYM) rise abruptly from coastal SB separating the Pacific Ocean on its southern face from the Santa Ynez Valley on its northern face. Downslope windstorms are frequently observed on the southern-facing slopes of the SYM. These winds typically intensify around sunset and throughout the night, and are known as Sundowner winds or Sundowners. The Sundowner Winds Experiment (SWEX), which extended from April 1^st- May 15 2022, involved 9 institutions and was the first experiment designed to advance understanding and predictability of Sundowner winds, while providing rich boundary layer data sets for developing new theories of downslope windstorms in coastal environments. This study discusses the integration of observations provided by sophisticated mobile and in-situ multi-sensor platforms focusing on case studies during the period. Using multiple lidars, we will show differences in mountain winds, contrasting laminar (next to mountain slopes) and turbulent (wave breaking region) flows. SWEX utilized 18 flux towers, 6 ceilometers and 3-hourly radiosondes from 4 locations, dropsondes and data from a Doppler and Raman lidars on board of the Naval Postgraduate School twin-otter aircraft to characterize and contrast the marine and continental boundary layers. These instruments characterized significant variability in the onset and intensity of the winds, and the presence and importance of mountain waves and wave breaking on the spatiotemporal variability of the winds. This talk will focus on a few case studies during the experiment.