In 1991 the U.S. Department of Energy created two High Performance Computing Research Centers to serve as intellectual homes for selected grand challenges and to conduct, manage and integrate the research activities necessary to enable progress toward their solution. (National Coordination Office for HPCC) To appreciate the scope of a grand challenge problem, consider the problem of modeling the global environment. Atmospheric scientists, applied mathematicians and computer scientists from several institutions including NCAR (National Center for Atmospheric Research) and the Oak Ridge National Laboratory collaborate in the CHAMMP project. Studying rainfall patterns is part of this effort. You may view some of their results can be seen on the WWW.