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Show avalanche factors. In the first example given above, the situation was complicated by a pre- storm period of heavy wind transport of snow picked up from the surface. The storm itself acted as a trigger for an avalanche condition which already existed. In the second example, the continuous sluffing, abetted by a high rate of settlement, canceled out the high P. I. Factor. P. I. must be interpreted in the light of its companion factors. The following tabulation covers P. I. studies of 25 storms. Those marked with an asterisk attained a P. I. Factor of 1 or more with strong wind action at P. I. of .10 or higher. The reader will note that in 11 out of 14 cases, avalanches of dangerous size were the outcome. This would be an overwhelming majority even if the three departures could not be explained on the grounds of the influence of related factors. The other 12 storms are included for purposes of comparison and illustrate the wide range of possible variation. The two Storm Plots following, with their interpretations, are graphic examples of P. I. studies. - 99 - |