Page:Types of Australian weather.djvu/16

12 On Chart No. 12, the following day, though a few storms were recorded, shows a great diminution in number. The col has widened and the monsoonal tongue has lost to some extent its thundery characteristics, having widened at the end. The accompanying barometric systems show no motion since the previous day, but the high pressures have intensified.



TYPE VI.—CYCLONIC THUNDERSTORMS.

This also, like the preceding one, is allied to the tropical low pressures, but in this case a defined cyclonic circulation develops in the lower extension of the tongue without the usual intensification of grades. From this source the thunderstorms radiate in easterly and southerly directions, and at times, as in the instance presented, a vast area is affected.

Chart No. 13, December 12th, 1893. As on the previous set the monsoonal tongue lies over much the same country, though with its axis more east and west; the high pressure to the west is very small, and the systems are somewhat fragmentary.