Radar and Microphysical Characteristics of Snowbands in Northeastern U.S. Snowstorms: Results from the 2020 and 2022 Deployment of IMPACTS

Winter snowstorms impact large population centers along the eastern seaboard of the United States and are characterized by mesoscale variability in precipitation type, snowfall rates and snowfall amounts. This variability is often associated with mesoscale structures called snowbands. Many aspects of snowbands remain poorly understood, such as whether increased snowfall rates at the surface are mainly due to confluence of horizontal motions, to variability of vertical motions, to thermodynamic instabilities, and/or to microphysical processes within and outside of snowbands. The Investigation of Microphysics and Precipitation for Atlantic Coast Threatening Snowstorms (IMPACTS) field campaign is a NASA-funded multi-year field campaign to study snowfall variability in winter mid-latitude cyclones primarily over the northeastern United States. The goals of IMPACTS are to improve the understanding of snowfall processes, remote sensing of snow, and the prediction of banded structure and evolution. IMPACTS addresses these goals through observations obtained during three deployments, two that occurred in winters 2020 and 2022 and the third planned for winter 2023. The primary observing platforms for IMPACTS are two research aircraft: the "satellite-simulating" ER-2, which flies high above the storms equipped with passive and active remote sensing instruments and the "storm-penetrating" P-3, which flies within clouds equipped with microphysical probes and environmental measuring instrumentation. Additional fixed and mobile radar and sounding observations and surface meteorological and precipitation measurements provide context for the aircraft observations.

The 2020 and 2022 deployments conducted more the 20 flights over a wide-variety of winter storms, including broad intense frontal bands, deepening cyclones, a rapidly deepening nor-easter type storm, and rapidly-moving shallow Alberta Clipper type storms. This wide range of storm types produced a wide variety of snowband structures. This presentation will highlight initial results from the 2022 deployment contrasting radar characteristics and microphysical properties within and outside of snowband structures observed in multiple storm events.