Supercooled Drizzle Development in Response to Semi-CoherentVertical Velocity Fluctuations Within an Orographic Layer Cloud

Abstract. Observations of super-cooled liquid water are nearly ubiquitous within wintertime, orographic layer clouds over the intermountain west; however, observations of regions containing super-cooled drizzle drops (SCDDs) are much rarer and the factors controlling SCDD development and location less well understood. As part of the Seeded and Natural Orographic Wintertime clouds – the Idaho Experiment (SNOWIE) goal of improving understanding of natural cloud structure, this study examines the role of fine-scale (sub-kilometer) vertical velocity fluctuations on the microphysical evolution and location of SCDDs within the observed mixed-phase, wintertime orographic clouds from one research flight of SNOWIE. This flight saw SCDDs develop in an elevated, postfrontal layer cloud with cold cloud tops (T