The average duration of wind from various directions is as follows:
From the north about 16 hours each week; from the northeast, the same;
from the east, 11 hours; from the southeast, 10 hours; from the south,
24 hours; from the southwest, 27 hours; from the west, 33 hours; and
from the northwest 31 hours.
During an individual disturbance lasting about 36 hours, we may have 8
hours of southwest wind; 4 hours of west wind, backing during the next 4
hours to south; 2 hours of south wind; 2 hours of southeast wind; 2
hours of east wind; 8 hours northeast wind and 4 hours north wind, 2
hours northwest, when it may be considered that a new pressure
distribution prevails.
The above values hold only for a storm moving with normal velocity. LOWS
are often blocked by slow moving HIGHS in advance. In such cases the
duration of east winds is greater.