382

THE NEW ZEALAND GAZETTE

No. 15

CLIMATOLOGICAL TABLE—Summary of the Records of Temperature, Rainfall, and Sunshine for January 1973—continued

The “normal” refers to the present site of the instruments. The standard periods for normals are: for temperature 1931-60, for rainfall 1921-50, and for sunshine 1935-60. No normals are available for stations with only short records.

*The sunshine recorder is not located at the station but is in the near vicinity.

A rain day is a day with rainfall equal to or greater than 0.1 mm.

Where the extremes of temperature and rainfall have occurred more than once during the month, the date of the first occurrence is given.

NOTES ON THE WEATHER FOR JANUARY 1973

General—January was dry and warm. For most farming districts of the South Island it was the third successive month with rainfall below normal, and conditions were very dry, with a lack of feed and in many areas poor prospects for hay. In the North Island conditions were mainly somewhat better but the dry weather was causing considerable concern from South Taranaki to Wairarapa.

Rainfall—Rainfall was below normal over nearly the whole country. In the South Island it was the driest January since about 1944, with mainly less than half the normal value but less than a quarter over the Clutha River catchment. In the North Island on the average it was about two-thirds of the normal value, with a considerable range. It was less than half the normal value in a number of east coast areas from Wairarapa to Bay of Islands and also in Southern Manawatu; but somewhat above normal in the Taumarunui-Taupo area.

At Dannevirke exceptionally heavy rain was recorded on the 6th. 78 mm fell in 2 hours, and of this 72 mm fell in 1 hour.

Temperatures—Temperatures were mainly above normal by 1°C. Highest departures exceeding 1½°C were recorded in the Rotorua-Gisborne area, around Waiouru, and in the Alps.

Temperatures were unusually high in some eastern districts on the 22nd when Gisborne recorded 37°C and Blenheim Aerodrome 35°C.

Sunshine—Sunshine was mainly close to normal over the North Island and 20-60 hours above normal over the South Island.

Weather Sequence—During the first 3 days of January an anticyclone was passing slowly across the country and the weather was fine, except for some rain in Fiordland and inland Northland.

For the next 2 days a depression was passing to the south and the associated trough of low pressure crossed the South Island. Considerable rain was reported in Fiordland and south Westland, with some also in north Westland and Buller, and scattered light falls elsewhere. Temperatures were warm in the east of the South Island. As the trough became stationary over the North Island on the 6th, rain fell in the Bay of Plenty. On the following day another trough affected the South Island with rain, especially in northern districts. On the 8th, rain was reported over the North Island with the trough stationary there. On the following day, with the trough to the east, rain still persisted in Gisborne and Bay of Plenty.

During the 10th and 11th a trough of low pressure, associated with a depression far to the south, crossed the country from west to east, and a secondary depression formed on it. Rain was general, with some considerable falls on the 11th, especially in the North Island. This day was also cool. The weather improved rapidly on the following day with the depression to the east and an anticyclone over the eastern Tasman Sea, but temperatures remained cool. Conditions were very similar on the 13th and 14th as the anticyclone moved slowly north-eastward. On the following day a trough of low pressure brought rain to the West Coast and the Southland coast. As this trough became stationary over the North Island on the 16th and 17th between two anticyclones, rain became general there.

From the 18th to the 20th an anticyclone was centred over the eastern Tasman Sea and extended also over New Zealand. The weather was fine, except for some light rain on the 20th on the Southland and Otago coasts. On the following day the anticyclone was centred somewhat further to the north and conditions remained very similar, with rain only on the Southland coast and the West Coast. Temperatures became very warm in eastern districts. From the 22nd to the 24th a trough of low pressure crossed the country bringing general rain, with some considerable falls in parts of Canterbury and northern Hawke’s Bay. The 22nd was a particularly hot day in eastern districts.

During the 25th and 26th a depression passed close to Southland and the associated trough of low pressure crossed most of the country. Rain was restricted mainly to western districts of both Islands. However, on the following day the trough became stationary to the north, causing rain in northern districts of the North Island. On the 28th and 29th an anticyclone over the Tasman Sea was moving on to New Zealand but a weak trough brought rain to some eastern districts. However, on the following day, with the anticyclone to the east, the weather was fine. On the last day of the month a depression was passing to the south-west of Macquarie Island, and as the associated trough of low pressure approached the South Island, rain was reported on the West Coast and in Southland and parts of Otago.

J. F. GABITES, Director.

(N.Z. Met. Misc. Pub. 012).