: The NASA Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) Earth-Venture Suborbital-3 (EVS-3) field campaign

Northeastern U.S. snowstorms have large societal impacts, and cause major disruptions to transportation, commerce, and public safety. Snowfall within these storms is frequently organized in multi-scale banded structures that are poorly understood, poorly predicted by current numerical forecast models, and difficult to observe from space-borne instruments. To address these shortcomings, the NASA Investigation of Microphysics and Precipitation for Atlantic Coast-Threatening Snowstorms (IMPACTS) Earth-Venture Suborbital-3 (EVS-3) field campaign will sample a range of East Coast snowstorms using airborne remote sensing and in-situ instrumentation during six-week deployments in three consecutive winters, starting this winter on 15 January 2020. The ER-2 aircraft will fly at high altitudes and carry a suite of remote sensing instruments including cloud and precipitation radars, lidar, and passive microwave radiometers to simulate satellite-borne instrumentation. The P-3 aircraft will fly within clouds and sample environmental and microphysical quantities using a turbulent air motion measurement system, microphysics probes, and a dropsonde system to sample vertical profiles of temperature, humidity and winds. These airborne measurements will be supplemented with ground-based measurements from rawinsondes launched from mobile sounding systems and at National Weather Service stations, ground-based radars stationed over Long Island, and the New York State mesonet ground network. With this suite of instrumentation, IMPACTS will provide observations critical to the understanding of the dynamical and thermodynamical mechanisms of snowband formation, organization and evolution. IMPACTS will also examine how the microphysical characteristics and likely growth mechanisms of snow particles vary across snowbands and apply this understanding to improve remote sensing and modeling of snowfall.