A Case Study of a Wake Low in northern Illinois and the WRF model prediction of the Wake Low

A wake low occurred in northern Illinois and southern Wisconsin, in the morning of May 30, 2008. The surface wind was 45 to 55 mph (22 to 28 m/s) with gusts to 65 mph (33 m/s). The WRF (Weather Research and Forecasting) model is run locally every 6 hours at the Weather Forecast Office in Chicago. This study is about how the WRF model forecast this wake low in an operational environment. We are investigating what occurs with wake lows, such as extreme pressure drops and strong surface wind. Then we will see if the WRF model can predict these events 6 to 12 hours in advance. We are investigating what adjustments to the model, such as grid spacing, and microphysics, we would make to obtain a better prediction of wake lows location and strength.

Several runs of the WRF were made with different initialization analysis data, grid spacing, cloud microphysics and convection schemes. The output of these runs were compared to surface, radar and upper air analysis of the day the wake low occurred