Page:Types of Australian weather.djvu/14

10 In Chart 9, the western anticyclone has extended northwards and has seriously contracted the diameter of the monsoonal low pressure, thereby facilitating or helping to cut off and start the cyclonic storm in the south; which has now developed a much steeper barometric grade and an energetic wind circulation, and is moving eastward without extending the rain area.

Chart No. 10 shows comparatively little motion in the cyclone, but it is considerably distorted, especially to the west, where the anticyclone is compressing the isobars by its easterly progress and in its endeavours to maintain its rate has overridden the cyclone in the north. As will be seen by a glance at these three charts, the rain resulting from this storm was most extensive and beneficial, and the winds under its influences were strong.

TYPE V.—CONDITIONS FAVORABLE FOR THUNDERSTORMS.

Upon comparison of charts setting forth this type with those of cyclonic thunderstorms, they will be found very similar; the main difference being the absence in this set of the cyclonic area at the end of the monsoonal tongue. The chief feature indicating