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THE NEW ZEALAND GAZETTE.
[No. 36

METEOROLOGICAL SUMMARY FOR MARCH, 1909.

The main features in the weather-conditions of March were somewhat similar to those of February. The weather was on the whole warm, and the winds light. Cyclonic movements principally affected the North Island and the north-east coast of the South. Westerly wave-areas of low pressure were not quite so much in evidence as usual, and while country with an easterly aspect had a total rainfall much above the average, on the western side and in the southernmost parts of the Dominion the rainfall was less than the normal.

A dry period was broken up on the 12th instant, when rains fell in the South Island from a small westerly wave of low pressure, which was followed by a large cyclonic movement from the north which traversed the North Island. This rain was most beneficial. On the 13th and 14th, with the rise of the barometer, thunderstorms occurred in Taranaki, and accounted for some heavy rainfalls in the interior of the North Island.

On the 8th the centre of a cyclonic disturbance passed northward of New Zealand, and was followed by a westerly wave of low pressure over the South Island on the 20th. These two disturbances resulted in much unsettled weather and some heavy rains, forming the maximum for the month at several stations.

On the 28th a cyclone of unusual extent appeared to the north-east of the North Island, and apparently united to the eastward of New Zealand with a westerly area of low pressure on the 31st. This cyclone traversed the east coast, and caused very heavy rainfalls between East Cape and Balclutha, and particularly in the neighbourhood of Christchurch, where a remarkable flood occurred, some streets being under water and houses inundated. While Hokitika on the west coast had less than half the normal, Christchurch on the coastal plains on the eastern side of the Alps had over three and a half times more than the average, a total of 6·47 in., which has only twice been exceeded in the records for that city. 3·16 in. fell on the 29th, and Lincoln had 2·30 in. at the same time. The total rainfall for the month also at Lincoln was 2·08 in. less than that of Christchurch.

The 28th and 29th were fine generally in the extreme south, and Mr. J. Geary, of Riverton, remarks that a splendid display of aurora australis occurred at this time; and the first frost occurred at Riverton on the 29th. Mr. H. B. Devereux’s report from Waihi for March is particularly interesting, and is as follows:—

“ This period, like the same month for 1908, has been remarkable for its excessive rainfall.

“ The mean temperature was also above the normal.

“ On the 29th we experienced the heaviest twenty-four-hourly rainfall which has been recorded here, and a review of the conditions, both antecedent and subsequent, are particularly interesting.

“ On Sunday the 28th the prognostics were remarkably ominous, the sky was overcast (pallium), and the detached cumulo-stratus underlying was peculiarly waviform; and the famous “pocky” cloud, said to be an infallible sign of storm in the Orkneys, was continually in evidence. Further, a heavy swell was coming in from the E.S.E., which was evidently the forerunner of an approaching cyclone, and this conclusion appears to have been justified.

“ Rain started on Sunday night, and by daylight on 29th heavy rain had set in.

“ Between 8 a.m. and 1 p.m. the fall was phenomenal, as the rates of fall below will show:—

Between 8 a.m. and 11.30 a.m.  ...  ...  ...  4·60 inches.
„ 11.35 a.m. and 1 p.m.      ...  ...  ...  0·64  „
„ 1 p.m. and 5.30 p.m.       ...  ...  ...  1·38  „
thence                    ...  ...  ...  0·25  „
——
Total for twenty-four hours ...  ...  ...  6·87 inches.

“ A reference to the barogram will show the remarkable waviform trace, and there is no doubt that a cloudburst occurred about 10 a.m., perhaps more than one.