Gu, Hongping, and Jiming Jin, Utah State University
In this study, the
Weather Research and Forecasting (WRF) model coupled with a one-dimensional,
ten-layer thermal diffusion lake scheme was used to investigate lake-effect
precipitation over the Great Lakes region. A five-year simulation was performed at 10 km resolution for
the cold season from 2003 through 2008. Initial and lateral boundary conditions
were provided by the six hourly, 32 km resolution North American Regional
Reanalysis. The results show that the coupled model is able to realistically
reproduce the observed precipitation over the areas strongly affected by lake
processes. In addition, severe snowstorms occurring over or near the Great
Lakes during the study period were selected based on radar reflectivity images
and precipitation duration and intensity measurements from meteorological
stations to examine the role of the lakes in triggering such storms. A
composite analysis of low-level stability and vertical moisture transport for
those lake-effect precipitation events are also presented here. Our results
indicate that realistic lake process simulations are very important to accurate
predictions of weather and climate in the Great Lakes region.