The Mesoscale and Microscale Structure and Organization of Clouds and Precipitation in Midlatitude Cyclones. IX: Some Effects of Orography on Rainbands

Abstract

Abstract The effects of orography on the mesoscale structures and precipitation processes in warm-frontal, warm-sector, wide cold-frontal, narrow cold-frontal and post-frontal rainbands in four Pacific cyclones are described. The rainbands were tracked with a Doppler radar as they approached the Washington coast and then for ∼150 km inland as they passed over topographic features ranging from modest hills to mountain ranges. The rainbands were affected in a variety of ways by orography, ranging from dissipation to formation, and precipitation from the bands was enhanced and reduced in different situations. These effects are discussed with respect to the large-scale flow, mesoscale air motions and precipitation growth mechanisms.