268 



THE WEATHER 



It is also true that many of the periods of unusual weather are 

 caused by the unusual behavior of HIGHS and LOWS. 



295. Unusual Paths of Lows. Figure 195 shows the usual 

 paths of autumn LOWS in the United States. In Fig. 196 are 

 the paths for November, 1909. Notice that most of the 



FIG. 192. 1160 lows classified, showing 27 paths. 



FIG. 193. 928 highs classified, showing 21 paths. 



tracks pass northeastward over Kansas and the upper 

 Mississippi valley. Figure 197 shows the effect on the pre- 

 vailing wind of the month, and on the average temperature 

 over most of the Mississippi valley, and also on the distribu- 

 tion of rainfall. 



