Surface pressure perturbations produced by an isolated mesoscale topographic barrier. Part II: influence on regional circulations

Abstract

This paper describes the detailed pressure and surface wind evolution associated with several important mesoscale pheomena in the region surrounding the Olympic Mountains of Washington state. The diurnal sea level pressure and surface wind variations of western Washington are described: lower pressure is observed over elevated terrain during the day with the opposite configuration at night. Next, this study documents the closed mesoscale lee lows that form in the lee of the Olympics during strong south-southwesterly synoptic flow regimes. Such lee lows create intense sea level pressure gradients and large ageostrophic accelerations along the eastern slopes of the Olympics. -from Authors