WHOLE VOL 



LAT. 



60' 



521 



SEA-LEVEL PRESSURE AT 10" INTERSECTIONS 



Lat. 60° N. Long. 90° W. 



950 mb. + 



Mean 61.9 62.9 64.6 66.6 66.1 60.4 58.2 58.3 59.: 



58.8 58.7 62.1 



61.4 



Lat. 60" N. Long. 70" 

 950 mb. + 



W. 



Date Jan. Feb. Mar. Apr. May June July Augr. Sept. Oct. Nov. Dec. Year 



56.7 



55.3 66.4 



67.4 54.6 66.4 



60.8 52.9 68.8 



66.0 57.4 51.9 



60.4 54.3 59.0 

 57.6 57.9 59.2 



54.5 57.8 64.1 



54.4 53.1 61.3 



52.5 54.8 62.8 



51.6 51.4 58.5 



5G.2 55.0 58.7 



58.7 



58.0 

 60.3 

 58.1 

 69.5 

 68.4 



61.0 

 58.5 

 68.8 

 57.1 



58.8 



