through March resulted from Arctic and polar high-pressure systems (clockwise 

 circulation) , as well as extratropical and tropical cyclones (low-pressure 

 systems with counterclockwise circulation). Winds originating as continental 

 or Canadian air masses generally move east across the US, producing initially 

 western and finally northern/northeasterly winds along the Atlantic coast; 

 extratropical "northeaster" storms associated with low-pressure systems tend 

 to move north along this coast, producing strong northeasterly winds followed 

 by winds from the northwest. 



68. Wind roses (Figure 7) for the spring and summer seasons, April 

 through September, of combined 1980 and 1981 data, showed the strong influence 

 of the tropical maritime airmass which produces winds that blow from the 

 southwesterly direction. The resultant wind speed and direction vectors 

 (Table 5) show an approximate balance of speeds and directions during July 



Table 5 



Resultant Wind Speeds and Directions 



for 1980 Plus 1981 



Month 



Jan 

 Feb 

 Mar 

 Apr 



May 



Jun 



Jul 



Aug 



Sep 



Oct 



Nov (1980 only) 



Dec 



Magnitude, m/s 



Monthly 



2.5 

 1.4 

 1.8 

 1.5 



Direction, deg True N 



343 

 318 

 324 

 217 



63 

 213 

 202 



23 

 285 

 359 

 317 

 334 



Seasonal 



Jan-Mar 

 Apr- Jun 

 Jul-Sep 

 Oct-Dec (no Nov 1981) 



Jan-Dec (no Nov 1981) 



1. 



,9 



0. 



.8 



0. 



.1 



2. 



,2 



Annual 



1.0 



331 

 215 

 262 

 340 



325 



32 



