94 



ILLINOIS ACADEMY OF SCIENCE 



lows a similar distribution. These results seem to stand quite 

 at variance with the statements sometimes found in elementary 

 textbooks on meteorology to the effect that the values of rela- 

 tive humidity, amount of cloudiness and precipitation are high- 

 est to the east and southeast of the center of the cyclone. 



Several factors probably contribute to the location of the 

 areas of greatest relative humidity, cloudiness and rainfall 

 north of the center of the low. Local conditions evidently of- 



LEGEMD 

 ■060-45 ?< 

 ^45-30 



□ 15-0 



Figure 19. Frequency of Precipitation 



fer an important modifying influence. The presence of the 

 Great Lakes to the northeast of Davenport probably constitutes 

 an important cause, also the presence of numerous small lakes, 

 and rivers in Wisconsin and Minnesota. The humidity of 

 the winds sweeping over these areas is probably increased 

 by an appreciable amount. Furthermore the Great Lakes and 

 other bodies of water would tend to decrease the temperature 

 of the northerly winds in the summer time, thus raising the 



