JUNE 29.] THE NEW ZEALAND GAZETTE. 1905

Government Meteorological Observatory.

METEOROLOGICAL Observations at Kelburn, Wellington, for the Month of May, 1939. Observations taken at 9 a.m.

Altitude of Observatory, 415 ft.

Means, &c. 1020·7 52·6 49·6 80 56·7 47·0 42·4 ... 2·7 173 228 104·2 ...

Mean earth temperature at l ft., 53·5°; and at 3 ft., 56·1°. Number of rain days, 13. Total rainfall, 44 per cent. below normal. Sunshine, 34 per cent. of the possible. Mean dew-point at 9 a.m., 46·4°; mean vapour pressure, 0·315 in.

Note.—Soft hail fell on the 27th.

DIRECTION OF WIND.

Gale (force 8 or more). Forces 4 to 7. N. N.E. E. S.E. S. S.W. W. N.W. Calm.

... | 13 | 5½ | 1½ | ... | 5½ | 7½ | ... | 1 | 5 | 5

NOTES ON THE WEATHER FOR MAY, 1939.

General.—Over much the greater part of the country May was extremely dry. For many places the rainfall was the lowest hitherto recorded and the same applies still more generally to the totals for the first five months of the year. The weather was mild with little wind and no very damaging frosts. The conditions favoured continued growth of pasture. Feed is generally short, however, especially for cattle, and though may caused a less severe drain on supplies than was feared, the prospects for the winter continue to cause anxiety. Supplementary feed crops have generally done poorly, especially in the South Island. The ground, also, has been too hard for proper cultivation. This has resulted in a smaller area of wheat being sown than is usual. The rains towards the end of the month relieved the situation in most districts, permitting ploughing to proceed. Apart from some shortage of feed the conditions have been very favourable for stock, which are generally in a healthy condition.

Rainfall.—The rainfall totals over the North Island averaged between 60 and 70 per cent. below normal. Numbers of places had a defect of over 80 per cent. In comparatively few places was half the average for May recorded. In the South Island conditions were only a little better in eastern districts. On the West Coast and in Stewart Island, however, the normal was in most cases exceeded. Parts of the Nelson Province had less than average, but the City itself had a wet month.

Temperature.—Temperatures were above normal practically everywhere, the average departure being about 1° F. Frosts were numerous and rather severe in the South Island owing to the anticyclonic weather prevailing with clear skies and little wind. In the North Island the nights were rather milder. Snow was confined to a few light falls on the ranges, and there is much less on them than usual at the time of year.

Sunshine.—Most places report considerably more than average sunshine, though the reverse was the case at Wellington and Hokitika. Invercargill also had slightly less than usual. Many places had over 30 hours above average. Tauranga reports 206·4 hours, Nelson 190·7, and New Plymouth 187·0.

Pressure Systems.—A dry type of pressure system continued to predominate in May, as in the preceding months of this year. Low-pressure troughs which lay approximately in a north to south direction and were quite active when passing eastern Australia, in nearly all cases lost energy before reaching New Zealand. The southern portion of the disturbance would move much faster than the northern so that the trough would tend more nearly into a west to east direction and become shallow. Before one anticyclone had moved off the North Island, another would be moving on to the South. Thus, though the whole gamut of wind changes was experienced frequently over most of the country, it was accompanied by little rain. At Wellington, for example, in one week there were five separate southerly wind changes with northerlies intervening, while only light showers were recorded.

Between the 5th and the 7th a moderate westerly depression crossed the South Island and caused widespread rain but chiefly in western and southern districts. On this occasion there was a heavy fall in Nelson which was of great benefit. From the 8th to the 13th a south-westerly type of weather prevailed with high pressure over the Tasman Sea and low to the east of New Zealand. Frequent light disturbances brought further rain to western and southern districts of the South Island, but over eastern districts and the North Island it continued dry. During this period there were gales on several days in the far south.

From the 14th to the 23rd though two more slight westerly depressions passed in the south, high pressure and anticyclonic weather prevailed over the Dominion and particularly the North Island.