November 2007

Sunny with low rainfall - severe soil moisture deficits in Marlborough and Central Otago – hot spell in the north and east

• Rainfall: Well below normal in many regions, especially Marlborough, Nelson, and Otago
• Temperature: Near average, apart from high temperatures in the north and east between the 20^th and 26^th
• Sunshine: Above normal in many regions

November 2007 was extremely dry in many regions, especially in the South Island, with totals of less than 10 mm throughout much of Nelson, Marlborough, and central Otago. The second half of November was very dry and very warm, with little rainfall in many areas. Severe soil moisture deficits (more than 130 mm) developed in Hawke’s Bay, Marlborough, and parts of Canterbury and Otago, with significant soil moisture deficits (more than 110 mm) in Bay of Plenty, Taupo, Gisborne, Wanganui, Wellington, and Nelson. Temperatures were cooler than average in the first half of November, while the second half of the month was noticeably warmer. The national average temperature of 13.4 ºC was 0.3 °C below average. The month was one of the sunniest November’s on record in Golden Bay, Nelson, Marlborough, Taranaki, and inland areas of Canterbury. Cloudy skies prevailed in the Far North. Anticyclones (‘highs’) were more frequent than normal in the Tasman Sea and over New Zealand.

The month’s overall weather pattern was produced by more frequent anticyclones in the Tasman Sea, often extending ridges of high pressure over New Zealand. This resulted in more frequent dry southerly quarter winds than usual over New Zealand.

Further Highlights

• The lowest air temperature during the month was -3.4 ºC recorded at Lauder on the 6^th.
• A hot spell affected the north and east of both islands between 20 and 26 November, with record high November temperatures recorded in many of these regions. The highest temperature during November 2007 was 32.8 ºC recorded at Blenheim Airport on the 25^th.
• Isolated areas of high rainfall occurred in coastal Waikato and Ruapehu on the 4th and parts of Fiordland on the 12^th.
• The highest wind gust of the month was 137 km/h from the south, recorded at Mt Kau Kau (Wellington) on the 14^th.
• Of the five main centres, Auckland was the warmest and wettest, Christchurch the sunniest, and Dunedin the driest of the five main centres.

Rainfall

Rainfall was les than 25 percent (quarter) of normal in Nelson and Marlborough, less than 50 percent (half) of normal in many other South Island and most eastern north Island regions. Rainfall was also below normal in Taranaki, Wellington, and coastal areas of South Canterbury, Otago, and Southland. Horowhenua was wetter than usual.

Temperature

Mean temperatures were about 0.5 ºC below average in many regions overall, but at least 1.0 ºC below average in north Taranaki. In contrast they were 0.5 ºC above average in Nelson.

Sunshine

Sunshine hours were well above normal in Taranaki, Manawatu, Kapiti, Golden Bay, Nelson, Marlborough, north Westland, and inland areas of Canterbury, and also above normal in Gisborne, along the Canterbury coast, Otago, and Southland. Cloudy skies prevailed in the Far North.

Full report

• Full details of the November 2007 Climate Summary

For further information, please contact:

Dr Jim Salinger – Principal Scientist, Climate NIWA National Climate Centre – Auckland Phone +64 9 375 2053 [email protected]

Stuart Burgess – Climatologist NIWA National Climate Centre – Wellington Phone +64 4 386 0569 [email protected]

Geoff Baird – Communications Manager Phone +64 4 386 0543 [email protected]

Acknowledgement of NIWA as the source is required.