SUMMER HOT WINDS ON THE GREAT PLAINS. 335 
bearable hot south wind; wind veered from south to northeast at 7 p. m. 
Hot winds from 1st to 8th, inclusive.” E. Shaw, voluntary observer. 
“Newspapers report considerable damage from hot winds during the 
first ten days of August.” I. M. Cline. 
These hot winds were preceded and accompanied by the 
following conditions: An area of low pressure made its ap¬ 
pearance to the north of Idaho on July 31 and moved 
eastward and southward, covering the northern and central 
slopes and the upper Missouri valley on the 2d of August. 
On the 3d this low pressure had moved out over the lakes, 
a high pressure area had appeared over the upper Missouri 
valley, and another low pressure was developing to the north 
of Montana, which extended southeastward to the central 
slope and moved slowly eastward, passing to the north of 
the lakes on the morning of the 6th. This low pressure 
area was followed by another, which developed in the 
vicinity of Calgary on the 5th, moved southeastward and 
covered the northern and central slopes during the 6th, 7th, 
and 8th, after which it moved to the north of the lakes. 
During the development and progress of these low pressure 
areas the barometer was above 30 inches over western por¬ 
tions of Oregon and Washington, and the general movement 
of the atmosphere was well defined from the Pacific coast 
across the divide toward the low pressure areas. The 
weather was generally cloudless over Kansas and Nebraska 
from August 1 to 8, inclusive. 
General Characteristics of the Summer Hot Winds 
of the Great Plains, and Conclusions as to their 
Causes. 
One of the most striking features of these winds is that 
while the atmosphere is heated generally and show's an ex¬ 
cess of temperature over the territory affected, abnormally 
heated narrow currents are often observed between which 
the air is much cooler. These currents are of very short 
duration, but often occur in rapid succession at neighboring 
