Interpretation of Arthur Green¬ís Weather Animation        
by Trudy Battaly        

1.  The seasonal distribution for BWs at Hook is from Sep 10 to Sep 27.   For the daily average number of BWs for the last 5 years, see Seasonal_Distribution or look over the brief background.
Arthur Green's animation substantiates this migration window for BWs:   The high pressure systems on Sep 1 to Sep 6 results in no or few BWs.

2.  Sep 9:   A low pressure system moves in from the south and dominates the weather patterns through Sep 13.  Numbers of BWs are still low.

3.  Sep 14:  A high from the NW dominates the area and the BW numbers begin to rise.  A cold front and a 2nd high push down from the north on Sep 15 and 16 and there are more hawks.

4.  Sep 17 & 18:  A few more BWs fly past as the residual highs are moving out.

5.  Sep 19:  Another cold front is followed by a high and the BW numbers peak at more than 2000 on both Sep 19 and Sep 20.

6.  Sep 25 & 26:  The next cold front and high result in the last double digit figures for BW for the year, as the BW window closes.