Page:Types of Australian weather.djvu/37

Rh TYPE XVI.—WIND BLOWING CONTRARY TO ISOBARS.

In this type the wind blows with considerable force in a direction directly opposed to that which the isobars would lead us to expect. For instance in No. 34, it will be seen that an extensive high pressure rests over the east coast, and the isobars are comparatively close together. The normal circulation with these isobars would be fresh north to north-west winds, when, as a matter of fact, strong southerly winds were blowing as far as Sydney with a velocity of thirty miles per hour. Such conditions are rather troublesome in forecasting; fortunately they do not come often, and the fact is not confined to southerly winds. The general direction of the coast line is northerly bearing east a little, a range of mountains from two to four thousand feet high runs nearly paralledparallel [sic] to it, and this local formation has a very important effect on the circulation of the wind; as in Chart 34 it seems to have more effect than the isobars, and probably the grade was rapidly intensifying and had not been long enough in existence to fully control the winds. It seems probable, so far as this type has been studied, that we should find that when the wind blows contrary to isobars, it does so because of some impulse given to it before the new grade had time to control the circulation.