71 An Analysis of Microphysics Scheme Performance in Numerical Simulations of the Lake-Effect Snow Event of 10-12 December 2013 during the OWLeS Field Campaign

Wednesday, 26 July 2017
Kona Coast Ballroom (Crowne Plaza San Diego)
W. Massey Bartolini, University at Albany, SUNY, Albany, NY; and J. R. Minder, R. D. Torn, and D. Keyser

Lake-effect snow presents a substantial forecast challenge for convection-allowing models, due in part to uncertainties in how best to parameterize microphysical processes. Here we focus on understanding these uncertainties for a lake-effect snow event that occurred during 10–12 December 2013 as part of the Ontario Winter Lake-effect Systems (OWLeS) field campaign. Throughout this case study, long-lake-axis-parallel snow bands persisted downwind of Lake Ontario, leading to snowfall accumulations as much as 101.5 cm (liquid precipitation equivalent of 62.5 mm) on the Tug Hill Plateau. For this event, we run nested simulations at 12, 4, and 1.33-km horizontal grid spacing using the Weather Research and Forecasting (WRF) model, configured in the same manner as the High-Resolution Rapid Refresh model. Sensitivity experiments are conducted by simulating the event multiple times with different microphysical schemes. Lake-effect snow band intensity and morphology are the primary differences between microphysics experiments, with relatively few changes in band position. Results from the WRF simulations are then compared to detailed observations from OWLeS, such as scanning and profiling radar data, surface snowfall and crystal habit observations, and aircraft measurements. These comparisons are used to determine which microphysics scheme provides the most realistic representation of microphysical properties and lake-effect snow forecasts.
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