Organization and Structure of Clouds and Precipitation on the Mid-Atlantic Coast of the United States. Part II: The Mesoscale and Microscale Structures of Some Frontal Rainbands

Abstract

Abstract The mesoscale and microscale structures of the clouds and precipitation associated with a frontal system on the mid-Atlantic Coast of the United States are investigated using radar reflectivity and Doppler velocity data, surface mesonet, conventional surface, upper-air and microphysical data. The frontal structure showed similarities to a warm occlusion, with code-air advection aloft preceding cold-air advection at lower levels. Six rainbands were observed in association with the frontal system. All of these rainbands developed within the region of coverage of the NWS WSR-57 radar at Cape Hatteras, North Carolina. Two were upper-level features, associated with a prefrontal surge of cold air and the main push of cold dry air aloft. These rainbands were similar in structure to prefrontal surge and wide cold-frontal rainbands, respectively, observed on the Pacific Northwest Coast. The microphysical and small mesoscale structures of the wide cold-frontal rainband are examined. Three of the rainbands ...