Page:Types of Australian weather.djvu/10

6 was a considerably less active feature, but on the other hand the monsoonal dip was somewhat more pronounced, and possessed two instead of one isobar. Following the 19th, the chart of 20th revealed no sign of the monsoonal tongue, and the continent was covered with a high pressure of very slight energy.



TYPE III.—DEVELOPMENT OF A CYCLONIC STORM IN LOW LATITUDES FROM A MONSOONAL DEPRESSION.

In Type No. 3 we have the development of a cyclonic storm out of a monsoonal depression. The seasonal peculiarity of this phase of the tropical low pressure is similar to that in Type No. 2. The cyclone seems to develop when the southern extension of the monsoon is out of proportion to its width, and it becomes so narrow at one part of it that the opposing winds which circulate round it interfere, set up the cyclonic circulation, and it then progresses eastward as a rain storm. (See Charts 6 and 7.)

These storms frequently develop in South-east Queensland, and they are generally most severe there; the quantity of rain which sometimes comes with them is very remarkable, as in the case of the phenomenal flood in Brisbane in 1893, which was the result of one of these storms.