Snowfall in the Sierra Nevada. 



The amount of snow remaining in the mountains dur- 

 ing the summer is determined by three factors: i. The 

 total snowfall on precipitation; 2. The distribution of 

 the snowfall with respect to time ; 3. The temperature or 

 general weather conditions during the melting period. 



If we are attempting at the end of spring to predict 

 the state of the snow for the coming summer months, 

 the third factor must of necessity be ignored, as it depends 

 on events which are yet to come and of which we have 

 no knowledge. The first and second factors, however, 

 are pretty well known by the middle of April or the first 

 of May, and we may use them as a basis for a rough 

 "forecast." 



The total snowfall in the Sierra at Summit Station is 

 given in the following table : — 



TOTAL SNOWFALL AT SUMMIT STATION, C. P. R. R. 

 Elevation 7,000 feet ; latitude, 39° 19' N. ; longitude, 120° 20' W. 



Snowfall Snowfall 



Winter of in Inches. Winter of in Inches. 



1870- 71 300 1889-90 776 



1871- 7^: 1890-91 331 



1872- 73 334 1891-92 380 



1873- 74 200 1892-93 634 



1874- 75 284 1893-94 511 



1875- 76 525 1894-95 685 



1876- 77 178 1895-96 544 



1877- 78 341 1896-97 560 



1878- 79 445 1897-98 262 



1879- 80 775 1898-99 480 



1880- 81 154 1899-00 406 



1881- 82 391 1900-01 363 



1882- 83 299 1901-02 391 



1883- 84 481 1902-03 395 



1884- 85 202 1903-04 — 



1885- 86 462 1904-05 368 



1886- 87 422 1905-06 418 



1887- 88 345 1906-07 626 



1888- 89 261 1907-08 330 



It will be noticed that 1880 and 1890 were the years of 

 heaviest snowfall during this period, amounting to nearly 



