Sensitivity of frontal circulations and precipitation to topographic forcing

A land-falling precipitating cold front during the CALJET experiment is examined through numerical experimentation as it interacts with the complex coastal topography of the California coast. Numerical experiments have been performed where the coastline and coastal mountains were rotated +/- 1 degree relative to the true coastline to yield slightly different incident flow directions. This talk examines these simulations to quantify the feedback of slightly different topographic forcings on the dynamics and evolution of the front. Extreme differences in the near-surface winds occur between the 3 simulations which directly impacts the precipitation distribution and the frontal structure itself. These differences seem to be related to the tendency of the flow to either be channeled by the topography or flow more directly over it under slightly different stratifications. The source of these differences will be examined as well as their feedback on the frontal dynamics.