Just as weather prognostication is as much art as science, so is the grading system for our fearless local weathermen and weatherwomen. A perfect performance is hard to achieve. For a snow event, the criteria include : 1) early identification of a potential storm, 2) preliminary assessment of the storm's magnitude, 3) accurate identification of onset, particularly when a rushhour is involved, and 4) accuracy in snow accumulation forecast for the immediate Chicago area both in the days leading up to the storm as well as just prior to its onset.
