Believe it or not, down here forecast are not based on the six hours clearing method although some people do it. They are based on what will be on the ground. Weather it's fluffy snow that sublimates or wet snow that settles. Ask Harvey Leonard on channel 5 down here and others. He bases the his forecast and many TV Mets on what will hit the ground based on storm track, duration, air temps, W.E. (Water Equivalency), and ground temps; not the manipulation of that falling to the ground. So far many TV Mets do not try to predict how some individuals will measure just what the public will overall see with their eyes when the storm is complete. Trying to work that six hour measuring technique into a forecast would be very difficult to do not to mention it is not as uniform as many may believe.