918 . JOURNAL OF FORESTRY 



the probable end of the growing season. The dates are chosen when 

 the chance of safety becomes less than 9 in 10. 



Monthly Weather Review, September, 1916. 



According to a compilation and map by A. J. 

 Hail Henry of the frequency of hail in the various 



ill regions of the United States, the region of most 



United frequent occurrence is a territory embracing 



States southeastern Wyoming, western Nebraska, 



Kansas, and Oklahoma, in which four hail storms 

 occur on the average in the year. Adjoining this territory a belt of 

 three storms a year embraces all of South Dakota, the balance of Ne- 

 braska and Kansas, the western and central parts of Iowa, and the 

 northwest of Missouri, besides all of Colorado. To the westward a 

 second region of hail frequency is found along the Rockies. East of 

 the Mississippi the annual average is two storms. 



In the Pacific Coast States, north to San Francisco, hail occurs from 

 November till March, and hence little damage to crops can occur. 

 Elsewhere hail storms occur in summer, with thunderstorms and tor- 

 nadoes. One hail insurance company in Iowa is cited as having paid 

 an average of over $77,000 a year for hail losses. 



Monthly Weather Review, Vol. 45, 1917, pp. 94-99. 



On May 16, 1917, an unusually severe hail- 

 Forest storm occasioned great damage over a section 



Influence of Switzerland, northwest of Lucerne. Accord- 



on ing to the severity of the damage, four concen- 



Hail trie zones could be recognized, which are mapped. 



The storm coming from the west was interfered 

 with by two other windstorms, namely, a Foehn from the south and a 

 so-called Biswind from the east-northeast. It is notable that toward 

 the west the zones follow each other more quickly, i. e., the limits lie 

 closer than on the east side. This is explained in that the Biswind 

 was stronger than the west wind, and thus retarded the progress of 

 the hailstorm. 



To the question whether forest exercised any protection, Oexlin, the 

 reporter, answers a decided yes : "Wherever forest areas were directly 

 located in the course of the storm the intensity zones were repressed," 

 so that the farms west of the Sedal forest experienced great damage. 



