S W Winds
After a northerly Wind for the most Part two months
or more, and then coming South, there are usually
three or four fair Days at first, and then, on the fourth
or fifth Day, comes Rain, or else the Wind turns North
again, and continues dry.
THIS is likewise a very judicious and very useful Observation, and yet
it is not a difficult matter to account for
t. It is a common
Observation, and a very true one, that there is usually fair Weather
before a settled course of Rain. The Winds that bring the dark rainy
Clouds that obscure the Sky, and cause dull cloudy Weather, often raise
these Vapours to such a height, that they are attracted into the cold
Region above our Sight, till being condensed there, they fall down upon
us again in Snow or Rain, according to our Author's Observation.
BUT if, after a seeming Tendency to Rain, there follow several Days of
fine Weather, it is a certain Indication that the Temper of the Air is
altered, and that these Vapours had been driven off before they had
time to condense, which is confirmed by the Change of the Wind on such
ALL these Observations are to be understood in a proper Latitude, and
not strictly and according to the very Letter. For Rain may fall the
sixth or seventh Day, or the Wind may change the second or third.
Besides, a Man who would make use of these Observations in the Country,
must consider attentively the Situation of the Place where he lives,
the bearing of the Sea, Marshes, Ponds, Lakes, Woods, Mountains, Rocks,
&c. For without making proper Allowances for these, all such
Observations on the Weather will be apt to fail him.