White lies in winter

Actually it’s official. The scare is over. The World Federation of Scientists, at its annual seminars on planetary emergencies, has been advised by its own climate monitoring panel that global warming is no longer a planetary emergency. But unless a climate scientist wrings his/her hands about global warming/climate change they face financial ruin, and in the NZ media barely last week there was the odd news from meteorologists that we have had “our warmest-ever winter”.

In continuing desperation to find even the smallest global warming evidence, the national climate office outlooks seem fond of focusing on mild spells and downplaying icy events. On the other hand farmers tend to bask in but distrust mild spells in winter and instead keep a sharp lookout for the deep polar blasts from south and southwest that can bring their financial ruin.

What farmers call winter is quite different to the call from Metservice and NIWA. What months constitute winter is provincial. Winter months will never be universal in NZ due to our deep variation in latitudes and terrains. Farmers work to operational timetables and not months. No region in NZ speaks for all in this regard, so weather experts can say anything.

In the upper North Island winter typically begins when pasture growth slows enough to dry off your cows, and ends when milking again resumes. Winter can then be anytime between April and September. Northland shares the same latitude as Victoria. But it is not nearly the same climate for South Island farmers at the same latitude as southern Tasmania, and whose winter typically begins with the first polar blasts bringing snowfalls and finishes with the thaws that come with rising temperatures. The south’s season can be anytime between April and October and need not for practical purposes have any relationship to winter in the North Island.

This winter was always going to be a mild one in the North Island (described on p287 of this year's almanac). But southern regions were expected to face icy wintry spells and polar blasts. Although August has now ended there is a lot more winter to come, and danger to lambing. That trend is clear given the past couple of years of lamb fatalities in September and/or October. Causally it is interesting to note that warmer winters in NZ correlate with years when midwinter full moons coincide with closest perigees for the year. This happened in 1977-8, 1987, 1995, 1996, and 2005. These were all warm winters, with the next such set of circumstances due in 2014 and 2022

To give legitimacy to the media report about the so-called warmth of the winter, NZ’s weather spokespersons have made a public claim that ”there has been an absence of cold snaps in recent months”. How true is this? Surely the following list of cold snaps, which seemed to come at about one per week on average, were not just imagined by all New Zealanders who are not meteorologists. They are printed here, having been extracted from print and online media sources between June and present.

20 to 22 June
"Heavy snow inland to low levels along with bitterly cold wind chills produced by severe gales..polar blast storm, lashed the country causing $33 million of damage.

28 June
"Surge of southerly air brings widespread heavy frosts"

10 July
"White-out conditions with snow to 700m have closed the Desert Rd in the central NorthIsland and eastern regions are experiencing some of the coldest weather of the year.

14 July
"A cold snap is racing up the country today and will bring wintry conditions to both islands."

19 July
In NZ "Winter is in full swing with another cold snap on the way, following flooding and wintry conditions which caused problems for drivers. In Australia, strong cold fronts bring snow"

24 July
"Antarctic snap - cold SW change, shot of cold air from Antarctica moves towards New Zealand

13 August
"An active and fast moving cold front is today flying across the Tasman Sea and will hit the western coastline of New Zealand early this evening bringing the potential for severe weather.

29 Aug
"Southerly change across NZ..snow to inland areas of South Island..change to a cooler air flow”.

It seems that the problem we now have is that nowadays instead of nature itself, weather science prefers to regard computer models as the reality, which is an agenda more politically and financially rewarding. The reading public do not know anything is amiss. What they read is accepted at face value because they do not understand the desperation for research funding. But should meteorologists speak for us or just for themselves?

Wherever I have gone about the country I have encountered turned-up fires and heaters. I am sure we have all felt the winter cold; and now we have a cool September and a cold October to look forward to, with lamb losses in more snow, before a shift to warmer December weather. As always for the time of year there are flowers and blossoms visible now, but most respond to strength of light fixed by month and not by temperatures.

Happily this winter has been fantastic for ski operators because all skifields bar none are lush with snow. That alone should demonstrate that the season has not been too over-warm. The smallest child will know that best snow cover comes in colder weather and thaws come when temperatures rise. Winters can have both warm and cold spells but a good and lasting snow-base still requires a cold enough season.

But don’t take my word for it. Take a drive along the Desert Rd and look at the extensive white of this year’s global warming lying all over Mt Ruapehu’s entirety. Then perhaps decide for yourself.

Ken Ring of www.predictweather.com is the author of Weather Almanacs for NZ for 2013 and 2014