9416866 Mass The complex terrain of coastal regions, such as exists along most of the western U.S. coast, has a major influence on local weather conditions. The interactions of such terrain with various meteorological phenomena, however, is not well-understood. The primary objectives of this project are to study and document: the coastally-trapped disturbances that propagate along the mountainous coastline of western North America; and the interaction of the large-scale flow and embedded disturbances (such as cyclones, troughs, and fronts) with coastal topography. Using an existing research data set collected under the sponsorship of the Office of Naval Research and the National Oceanic and Atmospheric Administration, this research effort will utilize both observational and numerical modeling approaches. First, the nature of orographically-trapped events and the interactions of the synoptic-scale flow and coastal orography under stable summertime conditions will be examined. Such features are often associated with significant transitions in temperature, wind, pressure and cloudiness within approximately 100 km of coastal mountains. Secondly, the project will address how the structures and dynamical balances of synoptic systems such as troughs and fronts change as they approach and cross a mountainous coastline during wintertime, less stable conditions. Such systems are often associated with significant coastal weather features such as mesoscale coastal ridging, coastal jets and alongshore surges. ***
