Rhudy - Van Leer Current Analysis

Current Forecast Analysis - valid 1pm EST 03 March 2011

A major topic of discussion as far as current analysis goes is the ongoing precipitation event moving through the upper Midwest. Shown in the first figure is the current radar image (1725Z) as well as the corresponding surface observations. In central Wisconsin is a maximum of radar reflectivity that is similar to the forecasted precipitation field in the 6-h precipitation field of the 12Z GFS211 run for today (forecast hour 6). This was our focus for our calculation. We did a simple parallelogram calculation of vorticity advection by the geostrophic wind at 500mb over central Wisconsin. The field used for this calculation is the 3rd image below. The calculated value was 6.45 x 10-9 s-2. This corresponds well to the GEMPAK calculated field in the 4th image below. A temperature advection 4-panel was also included for discussion of the traditional form of the QG omega equation.