• Haines, Donald A.
  North Central Forest Experiment Station, Forest Service-U.S. Department of Agriculture
  

Of all of the common weather phenomena, precipitation probably exerts the strongest influence on man and his activities. Since it influences man in different ways, there are a number of ways of describing the process. Most questions about precipitation can be reduced to "How much?," for precipitation amount is of prime concern in such activities as drought measurement and snow removal. There are, however, other ways of characterizing precipitation that are equally important. Knowing maximum precipitation amounts per unit time is essential in engineering storm drains. Knowing the frequencies of expected precipitation days is of help to the farmer during haying and other harvesting operations. And there are many other activities where precipitation, or the lack of it, plays a dominant role.