JANUARY 



FEBRUARY 



MARCH 



APRIL 



MAY 



JUNE 



JULY 



AUGUST 



SEPTEMBER 



OCTOBER 



NOVEMBER 



DECEMBER 



SCALAR MEAN SPEED 

 (KNOTS) 



OBSERVATION COUNT 

 PERCENT OF CALMS 



DIRECTION FREQUENCY: 

 BARS, EACH CIRCLE = 20%. 



25% OF ALL WINDS 

 WERE FROM NORTH- 

 EAST 



MEAN SPEED (KNOTS) 

 IS INDICATED BY THE 

 PRINTED NUMBER AT 

 THE END OF EACH 

 BAR 



MEAN SCALAR SPEED 

 OF ALL OBSERVED EAST 

 WINDS WAS 10 KNOTS 



Figure 17. 



Surface wind roses, Cape Hatteras and vicinity, 

 from data collected 1850-1960 



34 



