This image shows the current surface observations taken at 16 UTC on March 21, 2013. This will help determine how accurately the GFS 211 model predicted what would occur. The blue line cutting through Indiana shows freezing at the surface. Currently, the only places with observed temperatures above freezing are in parts of Kentucky and Illinois, while the GFS 211 predicted the region south of Indianapolis to be above freezing. However, the sun will continue to warm the surface well into the late afternoon, therefore causing many places to reach the temperature above freezing. I feel as though it is difficult to verify this until the maximum temperature high has been reached. The GFS 211 model did a great job predicting the precipitation. As shown by the observations, the places in Michigan and Ohio which are receiving snowfall, was predicted by the GFS. Both of these model runs were the 3/18 00 UTC model run.
These model runs were taken from March 19, 2013 at 00 UTC. In comparison to the GFS 211 model, the NAM 211 model has the freezing line significantly farther south, cutting through the Mississippi Valley. Currently, many places north of the freezing line are above freezing, and there are still several hours of sunlight to go. I feel as though neither the NAM nor the GFS did a good job predicting the surface freezing line. Similarly to the GFS, the NAM did a good job predicting precipitation, with most of it coming off of the Great Lakes or in the Appalachian Mountains.
Overall, the GFS HD did a great job predicting the model sounding. It predicted the temperatures to be a little warmer, but overall had the right prediction with surface temperatures and the change of the temperature throughout the atmosphere. This was taken at Lincoln, Illinois, at 3/21 12 UTC and the model was the 48 hour forecast taken from 3/19 at 12 UTC.