156
THE NEW ZEALAND GAZETTE.
[No. 5

SUMMARY FOR DECEMBER, 1908.

The weather at the beginning of December was fine and seasonable, but during the greater part of the month atmospheric conditions were generally very unsettled, cold, and damp for this period of the year. Low pressure of a westerly type prevailed, but tropical areas of low pressure were also in evidence at times. On the 15th and 16th the heaviest rains were from the latter cause in the North Island. On the 7th a cyclonic area had also united with a westerly low pressure, and caused a very general rainfall. On the 22nd and 23rd the east coast of the North Island was affected by a low pressure apparently to the north of East Cape. Westerly low pressure prevailed in the South on the 25th, and after that date strong westerly winds were general, with heavy rains on country with a westerly aspect; 8·42 in. fell at Otira from the 26th to the 31st, inclusive. The rainfall of the Dominion, though generally above the average for the month in previous years, was somewhat irregular, both in time and quantity, in various parts of the country. In the North Island the total rainfall was below the average only in the extreme north and in the vicinity of Wellington, but in excess in other districts, being about treble the average around Napier, more than double about Gisborne, and from 1 in. to 2 in. in excess in other parts. In the north-eastern part of the South Island the rainfall was less than the average, but in excess elsewhere, being double the normal from long records at Christchurch and Lincoln, though not so much in excess at other places. Electrical conditions were noted at various times in most parts of the country. On the 8th a widespread thunderstorm, accompanied with lightning and hail, was experienced in the North Island. On the 11th Canterbury was visited with a similar experience of a more local and severe type. On the 15th and 16th thunderstorms also occurred, and accompanied heavy rains, in the North Island. Snow lay low on the mountains on the 29th and 30th, and the weather was so cold that fires had to be kindled in homes in most parts of the country. On Christmas Day a remarkable fall took place (1·31 in.) at Dipton, and 0·70 in. at Nightcaps, in Southland. Mr. R. D. McLachlan, of Dipton, writes, “On the 25th there was a tremendous downpour; fully 1 in. must have fallen in the first half-hour. It appears to have been only local, little or none falling a few miles north or south. I don’t think I ever saw heavier rain in New Zealand, and seldom in Australia.” Another remarkable occurrence of a small tornado, which has been only rarely recorded here, but is frequently experienced in America and Australia, was reported by one of our most able observers, Mr. W. M. Hamilton, of Inglewood, Waimate, who writes, “Phenomenal conditions occurred on the 11th: heavy and warm atmosphere in the morning; about noon dark clouds collected and hung over for a time, with little movement in a still atmosphere. About 1 p.m. a whirlwind was observed. A dark cloud in the form of an inverted cone extended downwards, and a violent whirlpool from the surface extended upwards to meet it. The circular velocity must have been very intense. It struck my plantation, and uprooted manuka and well-grown oaks in a narrow strip of about ten to twenty paces. It rapidly moved away towards the north and turned to the north-east and out to sea. A straw-stack in my place was lifted and swept away.” On the same date Mr. B. V. Pemberton, of the Magnetic Observatory, Christchurch, about 113 miles northwards, reported, “A severe thunderstorm, accompanied with violent hail-shower, occurred at 1.15 p.m., and again at 4.25 p.m. (direction, from south-west). The thermograph exhibited a rapid fall of temperature—of 11° between 12 and 2 p.m., and an almost instantaneous fall of temperature of 4° at 4.45 p.m. The barograph curve during the afternoon showed several oscillations of the air-pressure. Until 1.10 p.m. the barometer was falling slowly. It then rose rapidly until 1.25 p.m., through 0·065 in., and fell again during the next half-hour. At 4.20 p.m. a second rapid rise occurred, the rise between 4.20 p.m. and 4.50 p.m. being 0·05 in. The barometer then commenced to fall again, and at 5.10 p.m. was still falling rapidly. The peak of high air-pressure in the curve lasted at the time of the first storm about sixty minutes, and during the second storm forty five minutes. The total rainfall during each storm was 0·37 in.

R. A. EDWIN.

Meteorological Office, Wellington.