With most of the leaves fallen, the countdown for spring is underway. And a person might count in all sorts of ways. One method is to keep track of the number of precipitation days: across the central portion of the United States about 50 days of rain or snow usually lie between now and April. Another gauge is the number cloudy days: in most of the country except along the west coast and the near the Great Lakes, there are almost never more than 75, rarely fewer than 60. Or one could monitor the