THE CLIMATE OF WESTERN CANADA 33 



24. Wind Direction. — Mr. J. F. Cross,* Superintendent 

 of St. John's College Observatory at Winnipeg has this 

 to say on the general subject of winds in the Prairie 

 Provinces : 



"The typical wind of the prairie section is north- 

 west, that of the Chinook (southern Alberta and south- 

 western Saskatchewan) southwest. Modifications of 

 these arise in several districts owing to local peculiarities, 

 and velocities also vary considerably. . . . Generally, 

 however, in Manitoba the direction tends north or south 

 with almost continuous moderate velocity and a num- 

 ber of light gales; in Saskatchewan the westerly type 

 begins to appear, while in northern Alberta the most 

 prevalent wind is due west. In southern Alberta and 

 especially in districts adjacent to the Rocky Mountains 

 the direction is usually southwest and the velocity rarely 

 exceeds 30 miles an hour. The force of the air move- 

 ments on the whole is greater in places of low latitude. 

 Hurricanes are, however, practically non-existent in the 

 Canadian West, the one notable exception being the 

 cyclone which visited Regina during the summer of 1912 

 and caused considerable damage in the business section 

 of the city." 



25. Atmospheric Humidity. — The meteorological data 

 on the atmospheric humidity of the West is very meagre. 

 In brief, it indicates that our atmosphere is very dry, 

 the driest being in the areas of lowest precipitation and 

 highest temperature, viz., southeastern Alberta and 

 southwestern Saskatchewan. 



A dry atmosphere increases evaporation. This is 

 noticeable, chiefly in the "Chinook" region where after 



* In "The Prairie Provinces of Canada'' 



