The Utility of Additional Soundings for Forecasting Lake-Effect Snow in the Great Lakes Region

Abstract

Abstract The impact of initializing a mesoscale model with additional sounding data over the Great Lakes region is investigated. As part of the Lake-Induced Convection Experiment (Lake-ICE) field study during the winter of 1997/98, six supplementary Cross-chain Loran Atmospheric Sounding System (CLASS) units and three Integrated Sounding System (ISS) units were used in addition to those from the standard synoptic upper-air network. The three ISS units were in the vicinity of Lake Michigan, and the six CLASS units were in the data-sparse region of central and northeastern Ontario and western Quebec. The Pennsylvania State University–National Center for Atmospheric Research fifth-generation Mesoscale Model running on a doubly nested grid is used to simulate the lake-effect snow event of 4–5 December 1997. This model output from a 30-km horizontal resolution grid shows that the six CLASS soundings capture a warm layer below 850 hPa that appears to be the result of diabatic heating from the Great Lakes. This ...