Page:Hunt - The climate and weather of Australia - 1913.djvu/138

Rh. 107, 108, 109.

Cyclonic Depression Bringing General Rains to Western Australia.—8th, 9th, and 10th July, 1912.—The great cyclonic depression shown entering Western Australia on the 8th July, between Perth and Geraldton, was probably of oversea tropical origin, but whether this was so or not it not only brought a splendid general rain to all Western Australia south of the Tropic, but, maintaining a trough connexion with the tropical low—pressure belt as it moved eastward, by the 13th, it gave much rain to a long strip of inland country extending from the Territory to Northern New South Wales, as well as to South Australia and Victoria.

Summer Monsoonal Rains.—6th to 18th January, 1913. Though the rainfall indicated on this chart is unusually widespread and heavy over Northern Australia, it occurs in connexion with a typical monsoonal depression, and there is no reason for regarding it as caused in any other way; that is, there is no necessity for assuming the intrusion of a tropical disturbance or any great atmospheric movement southwards. It was, however, preceded by the formation of a low pressure focus over the north-western interior of Western Australia and followed by a concentration of the rainfall over Eastern Queensland, where another slight low pressure focus was formed. The latter is shown by the chart of the 8th.