TYPES OF AUSTRALIAN WEATHER. 523 
thunderstorms is the narrowness of the col’ and somewhat con- 
gested state of isobars in the high pressures west and east of it, 
resulting in opposing winds. Those of the tropical tongues are 
hot and charged with moisture, while those of the 4 depressions 
are strong and dry. This type is met with during the monsoonal 
season. The rains resulting from this feature are not generally 
heavy, and though thunderstorms may be experienced over exten- 
sive areas of Queensland, New South Wales, and Northern 
Territory, a number of them may occur without any rain falling. 
Chart No. 11, January 17th, 1893, shows an extended and 
narrow tongue lying between two relatively high pressures, @ A 
depression similarly situated also exists in the south, this col or 
area of low pressure separating these two depressions is very 
small, and opposing currents of wind are noted there as blowing 
within close limits. Thunderstorms were occurring or had 
occurred in Northern Territory generally, over 4 great part of 
Queensland and in central parts of New South Wales, the rains 
upon this occasion, as is often the case, were not heavy, though 
they fell over an extensive and generally unfavoured area. 
TYPES 
oF 
AUSTRALIAN WEATHER 
NeW 
ALANUA <a yeas 
*» 
‘ 
a of 
- e 5 
Conditions for thunderstorms : 
It & 12 
1 For explanation of this term see P- 5326 
