It was an unsettled start to 2014 with a persistent southwesterly bringing cooler than normal temperatures and a good scattering of showers. Frequent cries of “Where’s summer?” were heard up and down the country.
More active spring like weather spread in for New Year’s day with heavy rain and thunderstorms that affected the west coast of the South Island and a few spots further east.
Further active troughs that brought heavy rain and gales continued through the first week of January. Strong to severe gales affected many western and central parts of New Zealand with another notable active trough on the 3rd and 4th of January. Winds gusted over 140km/hr in the hills surrounding Wellington. On the same day over 300mm of rain fell in the ranges of Westland and the afternoon high reached 28C in Gisborne in the warm nor'westers.
15th to 17th January: Cold southerly change
Temperatures struggled in some parts of the country over January - Dunedin city reported only five days with temperatures in excess of 20C this year compared with 14 such days the year before (-even reaching 30C on 23rd Jan 2013). Temperatures were at their coldest, though, on the 17th of the month when a brisk southerly change swept northwards over the country.
There was a dramatic temperature change for many parts of the South Island on the 16th as a southerly change pushed northwards. One of the best examples was seen in Ashburton. During the day the temperature, aided by a brisk northwesterly wind, had been able to rise in Ashburton to 31C, making it one of the hottest days of the month. However, as the southerly change moved across the town the temperature dropped by 12C between 4 and 5pm.
The cold change also brought a fresh dump of snow on the peak of Mount Hutt as it passed overhead.
At 1pm on 17th January the temperature recorded at the weather station in Dunedin city centre was merely 7C and the maximum for the day only 13C. There was a large temperature contrast across the country that day, as these observations show: while Dunedin struggled to get out of single figures the temperature in Whangarei was a very pleasant 24C.
21st January: Remains of Tropical Cyclone "June"
Earlier in the month the first tropical cyclone of the South Pacific season was named by the Fiji Meteorological Service. Tropical Cyclone Ian was a slow-moving system that brought several days of gales and rain to Tonga, briefly reaching category 5, before heading south-eastwards. The remains of Ian kept well clear of New Zealand tracking away to the east.
Almost a week later, during the evening of the 17th, Tropical Cyclone June was named over the warm waters of the Coral Sea. Unlike Ian, which remained slow-moving for many days, June was a fast moving system that tracked quickly south-eastwards past New Caledonia and towards the north of New Zealand.
Already a weak cyclone, only reaching category 1, as June moved southwards over the cooler waters of the Tasman Sea it continued to weaken. Never-the-less, as the remnants moved across the far north, strong winds and gales were features of the weather on the 21st. Cape Reinga reported a gust of 72 knots, 133kph, and a mean wind speed of 55 knots, 102kph. In Auckland the anemometer at the Harbour Bridge recorded a gust of 85kph.
26th January: Explosive cyclogenesis and a "viscous" cold front
A rapidly deepening area of low pressure, explosive cyclogenesis, formed off the eastern coast of Australia on the 25th and quickly barreled its way across the Tasman Sea. The pressure charts above show the analysis at 1am and then 12 hours later at 1pm on the 25th. As the low approached the west coast of the South Island it brought a period of rainfall for Westland and Fiordland.
As the low moved across the far south of the country on the 26th January the associated cold front swung across the north, with an intense burst of rain on its leading edge.
27th January: Return of the Anticyclones
The reappearance of anticyclones in time for Auckland anniversary day brought a spell of fine weather across the majority of the country. The remnants of the weekend’s front quickly cleared the northeast of New Zealand as high pressure pushed across from the Tasman Sea.
With the return of the anticyclones, this brought clear skies and light winds overnight on Tuesday 28th. These were perfect conditions for temperatures to fall quickly once the sun set, resulting in a chilly start to the morning for parts of the North Island. The coldest spots were over the Central Plateau where the temperatures dropped down to -3C at Waiouru and freezing point on the Desert Road. Wairarapa, too, experienced an unseasonable cold night with the minimum temperature at Masterton falling to 1.9C, but with plenty of daytime heating the temperature had quickly climbed back to 15C by 11am the following morning.