Preliminary Profiling and Polarimetric Radar Analysis of Convective Snowbands and Atmospheric Waves during the 25 February 2015 Southeastern U.S. Heavy Snow Event

During 24-26 February 2015, a Gulf low brought record snowfall across the Southeastern U.S., including a strip of 8” to 12” snow across northern portions of Mississippi and Alabama. Research groups from The University of Alabama in Huntsville's Severe Weather Institute – Radar & Lightning Laboratories performed intensive observations during this event with polarimetric radars, profiling radars & lidars, and balloon soundings. This study utilizes integrated observations from this Intensive Observation Period (IOP) to delineate and analyze mesoscale gravity waves, Kelvin-Helmhotz waves, and regions of convective snow in this winter cyclone. The high resolution measurements were obtained primarily from the UAH Mobile Integrated Profiling System (MIPS), which includes a LIDAR ceilometer, 12-channel microwave profiling radiometer (MPR), 915 MHz Doppler wind profiler, vertically pointing X-band radar (XPR), and standard surface meteorological measurements. Profiling data from the MIPS will be integrated with data from the UAH ARMOR C-band dual polarization radar and the National Weather Service KHTX WSR-88D S-band dual polarization radar to analyze the impact of atmospheric wave kinematics on precipitation substructures and possible enhancement of depositional growth, riming, and aggregation. Preliminary analyses indicate fine-scale enhancements in specific differential phase may be used to identify and differentiate atmospheric waves in stratiform snow regions from distinct snow bands. Analyses of integrated profiling measurements of stability, including changes in stability due to evaporation / sublimation, and subsequent impact on snow microphysics will be discussed. Additionally, the 25 February 2015 snow event will be compared to other convective snow events sampled during the Profiling of Winter Storms (PLOWS) field project.