Credit: Graphic courtesy MPEX.
This example from the evening of May 5, 2007, shows how even high-resolution models such as the NCAR-based ARW-WRF cannot yet predict exactly where and when thunderstorms will form. At left is a radar composite image that shows where showers and thunderstorms were occurring at 10:00 p.m. CDT on May 5. One of the intense storms in southwest Kansas produced a deadly tornado that destroyed some 95% of the town of Greensburg, Kansas. On the right is a 24-hour forecast generated by ARW-WRF, valid at 7:00 p.m. CDT on May 5. Although the model correctly depicted thunderstorms in Colorado and Kansas, it forecast a single powerful storm in northern Kansas instead of the multiple storms that struck southern Kansas.