The following figures are differences between model and VEMAP observational data from 1961-1990.  The precipitation units are percentage change from the 1961-1990 VEMAP observations.  These calculations were done by first upscaling the VEMAP half degree data to the resolution of the respective GCMs, computing the differences, and then smoothing the differences to create the images below.  The topography biases at the bottom were computed the same way.