THE POTENTIAL LONG-RANGE PREDICTABILITY OF TEMPERATURE OVER NEW-ZEALAND

Estimates of climate noise are made from temperature records of 20 New Zealand stations. The climate noise is variability of finite time ave rages, which is due to day-to-day fluctuations in weather, and it is u npredictable at long range (exceeding deterministic predictability lim its of about 2 weeks). This unpredictable part of seasonal or monthly averages is compared with the actual variance of these averages. The a mount by which the actual variance exceeds the noise variance is taken to be a measure of the potential long-range predictability. We find t hat about 50 per cent of the variance of seasonally averaged temperatu res is potentially predictable except for winter (June-July-August), w hen it is less. (C) 1997 by the Royal Meteorological Society.