Monday, 23 January 2012: 4:15 PM
Simulation of Atmospheric Marine Layer off Southern Oregon and Northern California
Room 338 (New Orleans Convention Center )
Mesoscale simulations using WRF with 12 km resolution were able to reproduce the complex flow of the lower atmosphere along Southern Oregon and Northern California that include two major capes and the Northern California large-scale bend. Ten-day composites of the strong NW flow episodes resemble the June 2001 monthly mean and any on a particular day. Predicted parcel trajectories in high speed expansion fan are supported by buoy measurements inshore and QuickSCAT winds in the offshore area. The large scale synoptic setup of the North Pacific anticyclone offshore and heat low over the southwest U.S. establishes an intensified along shore gradient to south over a limited area of the West Coast. The lower atmosphere, including a marine layer, responds as a quasi-Bernoulli flow with a wave like feature in the lee of each major cape, but sometimes as a double wave structure responding to the Cape Blanco and Cape Mendocino topographic complex. Maximum 10-m speeds are limited by the inbound layer depth and the stability of the layer above, so that the usual range of summer conditions keep the maximum speeds to less than 20 m/s.