Historic: September 1980

[RWood]

September 1980: Windier and milder than usual, with an exceptionally high frequency of northwesterly winds. There were violent thunderstorms in the early hours of the 10th in western areas of the North Island, and a tornado in North Taranaki caused extensive damage to farm buildings, power blackouts and some loss of stock. Avalanches were occurring regularly in August on the Te Anau-Milford highway, and 5 more major ones were reported in September.

Rainfall: Rainfall was above normal in the far north and south, and in western areas. The Southern Alps and West Coast received more than 150% of average. Over the rest of the country rainfall was below normal. In many eastern South Island districts little or no rain fell in September, while the east of the North Island had less than 30% of normal in many places. Kaikoura reported nil rainfall, as did Lyttelton. [Maruia had 422mm, its highest for September, and Cropp Hut 1665mm]. At some West Coast stations rain (0.1mm or more) fell on every day of the month, but most had 26-28 rain days.

Temperatures: Mean temperatures were slightly cooler than normal on the West Coast, but above average elsewhere. Many places in the east of both islands were more than 1.5C above the September normal. Maximum temperatures in eastern South Island areas during the latter part of the month were on most days over 5C warmer, due the the foehn effects of strong NW flows.

Sunshine: Sunshine was above average in the east of the country north of Oamaru, and about Cook Strait. Elsewhere it was below average, with some large areas 30 hours or more in deficit. Christchurch (205) had its sunniest September since 1958. Very low totals included 83 hours at Palmerston North and Invercargill, 75 at Hokitika and 59 at Greymouth (NZ record low for September – about 18% of the possible).

[Tauranga reported a value of 121 but given the readings at Auckland City (147) and Whakatane (160) this value looks quite suspect].


Sources: NZ Met. Misc. pub. 107 (Climatological table, NZ Gazette) and NZ Met. Misc. pub. 109 (Meteorological Observations) - additional comments by the poster.

[rainfan]

From the "Book":

"From August 1980 there was a marked change to a westerly wind regime with a reversal of pressure anomlies to the N & S of the country with high rainfall/snowfalls for south Westland with very dry, warm weather in the east of both Islands"