Mass, Clifford FMcClung, Brandon2019-08-142019-08-142019-08-142019McClung_washington_0250O_20041.pdfhttp://hdl.handle.net/1773/44030Thesis (Master's)--University of Washington, 2019Strong, dry downslope-directed ow over northern and central California known have played a critical role in a number of regional wildres. Termed diablo winds, these winds are more frequent over the Bay area than along the western slopes of the Sierra Nevada, where the highest frequency occurs on the mid-slopes of the barrier. For the Bay area, there is a frequency minimum during mid-summer, a maximum in October, and a declining trend from November to June. The Sierra Nevada locations have their minimum frequency from February through August, and a maximum from October through February. For the Bay area sites, there is a maximum frequency during the early morning hours, with a large decline during mid-day, while the Sierra Nevada locations have a maximum frequency approximately three hours earlier. There is profound amplication of upper-level ridging over the eastern Pacic, and high pressure building into the Pacic and then the intermountain west, before the onset of Diablo wind events. The simultaneous development of a coastal pressure trough leads to large pressure gradient over the Sierra Nevada and northern California. Diablo wind events are associated with colder than normal temperatures east of the Sierra Nevada, with rapid warming of the air as it subsides into coastal California. The large horizontal variability in Diablo wind frequency and magnitude suggest the importance of exposure, elevation, and occurrence of mountain wave-related downslope acceleration.application/pdfen-USnoneAtmospheric sciencesAtmospheric sciencesThesis