Climate Summary for November 2014

A cool month for most of the country.

Overview

November 2014 was characterised by air pressures which were lower than normal over New Zealand and to the south of the Chatham Islands, with higher pressures than normal present in the north Tasman Sea.  This pressure pattern resulted in westerly flow anomalies over New Zealand. Southerly outbreaks occurred frequently during the month, and these contributed to the changeable and generally unsettled weather that characterised the month for many parts of the country. Cold fronts associated with these southerly outbreaks triggered a number of thunderstorms, with many locations observing lightning and hail at least once during the month (see Highlights and extreme events section for further details). The high frequency of southerly outbreaks were reflected in temperatures for the month as a whole, which were below average (-1.20°C to -0.51°C) for southern and western parts of the South Island, and central, western and northern-most parts of the North Island. November temperatures were particularly low for Fiordland, parts of the Southern Lakes and Central Otago, the Canterbury High Country and central-western parts of Waikato where temperatures were well below average (> 1.20°C below average). Despite the generally cool conditions overall, warm periods occurred when westerly flows became established, enabling the foehn effect to increase temperatures in eastern parts of both islands. This was especially notable during the last ten days of the month, when daily maximum air temperatures frequently reached the mid-20’s and beyond in Christchurch, Blenheim, Napier and Gisborne.  The nation-wide average temperature in November 2014 was 13.4°C (0.3°C below the 1971-2000 November average from NIWA’s seven station temperature series which begins in 1909)^[1].

The westerly flow anomaly for the month as a whole contributed to rainfall totals that were above normal (120-149%) or well above normal (> 149%) for western and southern parts of the South Island, and isolated locations in the North Island including Palmerston North, Whanganui and Dargaville.  The orographic effect of air moving eastwards over elevated land meant that rainfall was below normal (50-79%) or well below normal (< 50%) in eastern parts of both islands such as Central Otago, South Canterbury, Marlborough, Hawke’s Bay, Gisborne, Bay of Plenty and the Coromandel Peninsula. It was a similarly dry month for Nelson, Wellington, the Kapiti Coast and Auckland. Remaining areas of the country typically received near normal rainfall (within 20% of normal) for the month.

As of 1 December 2014, soil moisture levels throughout New Zealand were closely reflective of the rainfall anomalies observed during November. Soils had dried considerably for many areas of the North Island in comparison to the soil moisture levels observed on 1 November. Specifically, soils had become notably drier than normal for Wellington, southern Wairarapa, Hawke’s Bay, Gisborne and Bay of Plenty. In the South Island, soils around the Nelson region had become considerably drier than normal for the time of year, whilst soils on the east coast of the South Island remained drier than normal. In contrast, soils were wetter than normal for the south of the South Island on the back of an especially wet November. Soil moisture levels were largely near normal for remaining parts of New Zealand.

Most of the country received near normal (90-109%) or above normal (110-125%) sunshine hours for November. It was particularly sunny for eastern areas of the North Island, and eastern and northern parts of the South Island, with well above normal sunshine (> 125%) observed in Gisborne, Blenheim and Cheviot. In contrast, it was a cloudy month for south-western parts of the South Island, where sunshine was below normal (75-90%) or well below normal (< 75%) for the south-western parts of the South Island.

Further Highlights:

• The highest temperature was 31.1°C, observed at Christchurch (Riccarton) on 22 November.
• The lowest temperature was -3.4°C, observed at Middlemarch on 11 November.
• The highest 1-day rainfall was 226 mm, recorded at Milford Sound on 21 November.
• The highest wind gust was 209 km/hr, observed at Cape Turnagain on 18 November.
  • Of the six main centres in November 2014, Auckland was the warmest, Dunedin was the coolest, Tauranga was the driest, Hamilton was the wettest and cloudiest and Christchurch was the sunniest.
  • Of the available, regularly reporting sunshine observation sites, the sunniest four centres[2] so far in 2014 (1 January to 30 November) are: Whakatane (2477 hours), Blenheim (2289 hours), Nelson (2283 hours) and Lake Tekapo (2255 hours).

Download the full report:

Climate summary for November 2014

Climate statistics table:

Climate statistics for November 2014 [62Kb PDF]

For further information, please contact:

Mr Chris Brandolino NIWA Forecaster – NIWA National Climate Centre Tel. 09 375 6335, Mobile (027) 886 0014