JULY 5.] THE NEW ZEALAND GAZETTE. 2099

Government Meteorological Observatory.

METEOROLOGICAL Observations at Kelburn, Wellington, for the Month of May, 1934. Observations taken at 9 a.m.

Altitude of Observatory, 415 ft.

Mean earth temperature at 1 ft., 52·1°; and at 3 ft., 55·2°. Number of rain days, 12.

DIRECTION OF WIND.

NOTE.—A cool, late autumn month, with temperature about 1·7° below normal. Total bright sunshine, 37 per cent. of the possible; five sunless days. Precipitation was 14 per cent. above normal. Gales occurred on the 8th, 15th, and 17th; hail was recorded on four occasions; there was a heavy thunderstorm on the afternoon of the 4th, accompanied by torrential rain, and lightning was seen on the evening of the 2nd. Frosts were recorded on the 19th, 27th, and 30th. Mean dew-point at 9 a.m., 43·9°; mean vapour pressure, 0·286 in.

NOTES ON THE WEATHER FOR MAY, 1934.

General.—Though there were two rather severe storms during May, the weather for the greater part of the month was relatively quiet. Temperatures were, in the mean, considerably below normal, but there was only one really severe cold snap, that accompanying a southerly gale on the 17th to 18th. In the South Island, especially on the east coast, there was much cloudy and misty weather. A certain amount of growth took place in pastures in most districts, and stock generally are reported as being in good condition. The soil is generally well provided with moisture, the effects of previous dry spells having practically disappeared even in Nelson and Marlborough.

Rainfall.—In much the greater part of the North Island the total rainfall was considerably below average, but small excesses were recorded in some areas around Auckland, in southern Taranaki, and in southern Wellington. In the South Island the Nelson Province and Stewart Island had rather less than the average, but in the remainder it was a very wet month. Parts of Canterbury had almost three times the normal for May.

Temperatures were below average everywhere except in parts of Otago and Southland. The departures were rather large in the North Island, averaging from one and a half to two degrees, but were generally smaller in the South. Owing to the large proportion of calm nights frosts were rather numerous.

Sunshine.—In the North Island the month was a fairly sunny one, but most of the South Island recorded much less than the average. Tauranga had 183·0, Nelson 177·1, New Plymouth 162·5, and Napier 162·2 hours.

Pressure and Weather Systems.—The first event of meteorological importance in the month was the development of a remarkable cyclonic storm which reached its maximum intensity on the night of the 3rd. On the 2nd there was a trough of low pressure located west of New Zealand. It was not very deep, but it extended in almost a due north and south direction from north of Norfolk Island southward to beyond the region covered by our reports. It marked the boundary between warm air coming from the tropics and a colder mass lying to the west of it which had a far southern origin. On the 2nd there was a small centre of low pressure in the above-mentioned trough situated in the neighbourhood of Norfolk Island, the lowest pressure being about 29·8 in. Under the circumstances then existing it was proper to expect that the centre would move towards North Auckland and cause north-easterly gales and heavy rains there, but it would have been difficult to foresee the striking changes that did take place. On the morning of the 3rd the storm centre had developed into a deep and full-fledged cyclone, the lowest pressure being near Cape Maria van Diemen and amounting to about 29·2 in. The southward movement was continued, and on the morning of the 4th the centre, where the pressure was now about 29·1 in., was near Wanganui. At this stage the storm was intensified through interaction with an older centre farther south. West of a line running from Russell through Wanganui, Wellington, and Christchurch on down the east coast was cold air moving from the south or south-west, while to the eastward was warm air moving at the speed of a gale from a north-easterly direction. Thus, at Akaroa a north-easterly gale was blowing while at Christchurch there was a light southerly. This meant that the warm moist air from the north-east was climbing rapidly up over the cold southerly—a condition ideal for the formation of heavy