SECTION III., 1910. [51] Trans. R.S. C. 
IV.— The Chinook in Southern Alberta and Temperature Inversions at 
Sulphur Mountain, Banff. 
BYAR FS STUPART. 
(Read September 27, 1910.) 
A study of some of the remarkable characteristics of the climatic 
conditions of Alberta has led to an investigation of the phenomena of 
the Chinook wind and of the inversions of temperature which are found 
to be not infrequent in the higher levels of the Rocky Mountains. For 
this investigation daily observations for the six years 1904-9, at the 
following stations, have been considered: Outer Coast, Port Simpson, 
Rivers Inlet, Quatsino, Clayoquot and Bamfield. The Island, Victoria. 
Lower Mainland, New Westminster, Agassiz, Ladner’s Landing. Jn- 
terior Plateau, Kamloops, Okanagan. Mountains, Revelstoke, Glacier 
House, Golden, Barkerville, Banff and Sulphur Mountain. Prairies, 
Calgary and Edmonton. 
The first and most obvious conclusion is that the Alberta chinook 
is a strong southwest or west wind which blows between the coast and 
Alberta when a well-marked area of low barometric pressure is passing 
eastward across the more northern part of the Province, and with these 
conditions a heavy general precipitation occurs on the outer coast line 
and also in a more spasmodic manner on the western slopes of the 
Mountain ranges of the Interior. The Chinook is not pronounced unless 
the barometric gradient be steep enough for strong winds. It is found 
that the temperature of the winter chinook in Southern Alberta is 
approximately equal to the temperature on the outer coast of British 
Columbia and may exceed 50. The conditions which precede and 
accompany the Chinook all tend to confirm the theory, that the fohn 
results from the retardation, due to the condensation of moisture, in the 
rate of cooling of the air ascending the western slopes of the mountains 
and subsequent warming at the ordinary adiabatic rate in the descent of 
the eastern slopes. Observation does not shew that a change 
to higher temperature on the Alberta prairies is indicated much in 
advance by a change occurring on Sulphur Mountain, while on the other 
hand cold waves setting in from the north are usually well marked on 
the plains before any change occurs at high levels. 
Accompanying tables and diagrams shew that the averge mean 
temperature of a term of years is in every month of the year higher at 
Banff and at Calgary than on the top of Sulphur Mountain and that 
the mean daily range of temperature at Calgary is approximately double 
what it'is on the Mountain. It is a most interesting fact, however, 
tha} in abnormally cold winter months on the plains, the mean tem- 
