Edwin. — Meteorology of New Zealand. 557 



Anticyclone having Three Maxima (Southern Hemisphere). 



JFUf2. 



In this country anticyclonic pressure is not usually dis- 

 turbed northward of the latitude of East Cape : it frequently 

 extends southward to the latitude of Hokitika, and, though not 

 unusual further south, it is generally of shorter duration than 

 in other parts of the country. While high pressure is likely 

 to continue the sunset colours are always in the west, and 

 indicative of fine weather ; but when a westerly low-pressure 

 wave is approaching the sunset colours become prominent in 

 the east. Sometimes, when pressure is above 303, a most 

 remarkable cumulus cloud forms in the eastern sky, having 

 three or four very lofty summits composed of closely packed 

 globular masses, which towards the base are of great size, 

 decreasing upward until the topmost ones are very small. 

 The cloud-base is heavy, compact, and of an undulating form, 

 with edges of a whitish colour. All portions of the cloud are 

 in continual movement, and the upper parts are of all shades 

 of delicate greys, but the base is of deep bluish-black or 

 neutral tint. When the summits are lit up with sunset tints, 

 while the base remains dark, the whole cloud has a very 

 beautiful but threatening appearance. Strong northerly winds 

 set in soon after the cloud forms, and soon increase to a 

 heavy gale, pressure decreasing slowly until at about 30 in., 

 soon after which it falls rapidly, with wind moderating, and 

 the cloud passing away to the eastward. 



Wave-pressubes. 

 Following anticyclone pressures there are usually these 

 low pressures from the west ; their wind-movement is from 

 the north-north-east or north towards west, with decreasing 

 pressure as the first minimum or wave approaches ; but in- 

 creasing and the wind changing from the west toward south as 

 it passes to the eastward, the wind then changing back through 

 the west to north or north-north-east, and pressure again de- 

 creasing with the advance of the next minimum. These oscil- 

 lations of both wind and pressure continue for uncertain 

 periods, but are ultimately succeeded by anticyclonic pressure. 



