Page:Weather Facts and Predictions.djvu/26

 When the wind becomes N.E. and two days pass without rain, and on the third day the wind does not veer to the S. nor does rain fall, the wind will probably continue N.E. for eight or nine days all fair and then veer to the S.

The wind is usually more strong in veering from N. to W. by S., than in veering from N. to S. by E.

Change of wind "with the sun" (veering N., E., S., W.) is a general indication of fine weather, but "backing" (N., W., S., E.) presages rain or wind, or both combined.

Changes of wind in Ireland, Wales, and Cornwall usually precede changes in the midland and Eastern counties of England by one and a half to two days.

If in unsettled weather the wind veers from S.W. towards N.W. at sunset, an improvement in the weather may be looked for.

Strong winds are more persistent and uniform than light winds. That is to say, if a strong wind is blowing at any one place, a similar wind also strong will prevail over a considerable tract of country, but if the movement of the air is feeble, very different winds will be registered at places not very far apart.

In our latitudes a Northerly current becomes more Easterly the longer it lasts, and, therefore, a N.E. wind is a N. wind which has come from higher latitudes than a wind which reaches us as a N. wind; and similarly, a S.W. wind is a S. wind which has come from lower latitudes than our S. wind.