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Phil’s weekly column: The speed limit debate + a major polar blast this winter?

Another week has zipped by and this one has been an entertaining one.  Politics here and overseas have  overshadowed most weather news but a wet start to the week saw the mainstream news running stories about the sub-tropical soaking for northern areas. 


Accuracy

The heavy but narrow belt of rain brought relief to dry farms and watertanks across the upper North Island – but failed to reach everywhere.  Canterbury was promised plenty of rain by some forecasters, but very little arrived.  WeatherWatch.co.nz said there was certainly potential for up to 12 hours of heavy rain in Canterbury but apart from that one prediction we expected cloudy weather and drizzly showers for the most part.  

It was a tricky one to predict but yet again it proves that WeatherWatch.co.nz doesn’t always jump at every chance to talk about severe weather. We make our own calls and weigh up our own risks.  As always it’s up to the public to chose the forecaster they feel is most accurate and honest.


Speed Limit

The national speed limit has been in the headlines this week after suggestions some highways – particularly Auckland’s new motorways which really are world class.  The idea will be a controversial one.  We have an unusually high focus on the road toll in this country.  Not that that is a bad thing, but clearly a lot of tax money is used to campaign for safer driving. 

Personally, I support the idea of SOME 110km/h speed zones.  Certainly the new motorways in Auckland are built to handle faster traffic – and as one nzherald.co.nz reader wrote “if 110km/h scares you maybe you shouldn’t be driving on a motorway”  In most western nations speed limits of 110 to 130km/h is standard on the big safer highways. 

A suggestion was made that if conditions were foggy, then motorists would slow below 110km/h – that Kiwi’s are intelligent enough to work that stuff out – but that often government officials think otherwise.

I say why limit it to Auckland?  For those who have driven across inland parts of the South Island you’ll come across some of our most incredible highways – big wide State Highways with little traffic, little rain, and few corners.  There are other roads around the North Island too that could be safely made 110km/h zones. The weather in New Zealand, despite being changeable, is fairly kind to motorists.  We have few major storms and even fewer snow days.  Freezing rain is also rare as is black ice on most major highways.

An idea that I believe is worth looking into at least – there are certainly arguments on both sides but we fully support some 110km/h speed zones on our safest roads.


Is there a major polar blast coming our way this winter?

Back in March I made a prediction that this winter we could get a repeat of the polar blast we had last August that saw snow falling in Auckland and Northland.  While such a weather system tends to only hit NZ every 30 years or so, the air pressure systems we had last winter haven’t left us.  We have no El Nino or La Nina to drive another pattern in either.

But it’s the intense highs that really prompted my somewhat extreme prediction.  Granted it would be a bit of a fluke to get it twice in two years – the reason why the average has been every 30 years is because so many things have to line up for it to really pull snow clouds up to the ‘Winterless North”

However just several weeks after I made that prediction take a look at this Weathermap.co.nz prediction for next Wednesday (image above) – while not a carbon copy of last Autumn’s storm is does have similarities – the main one being the size of the high over Australia (coloured in blue which means light winds).  This intense high stretches from the tropics to well into the Southern Ocean.  In August last year a high in the same place stretched a little further north and quite a bit further south – but had a similar structure with a decent low to the south east of New Zealand also helping pull up strong, bitterly cold, southerlies.

The low and high worked in tandem to dredge up Antarctic air and push it right over New Zealand and then into the sub-tropics – very rare.

So what are the chances of it happening this year?  Well, normally I’d say there is a less than 5% risk each year of this happening – but this year I’d put it closer to 40%.  Based on the intense highs and general set up.

But for a national snow storm to happen we not only need all the ingredients to come together – but they need to happen in the depth of winter which is July and August…only time will tell if the current pattern lingers until then.

– Philip Duncan


Have Your Say

What are your feelings on having another snow storm this year – will you be wishing for one, or hoping we don’t get hit again?  Also, do you think some of our safer highways in New Zealand could have the speed limit shifted to 110km/h or higher?  Post your comments below

Comments

Niki on 12/05/2012 5:53am

I hope it does snow again here in Palmerson North. Will always remember it last year it started with a small thunderstorm then snow later on that night and was on my birthday :D. My daughter loved it, although i had to try keep her indoors so she wouldn’t go running outside in her jarmies to play, her smile and fascination with it made me smile. Hopefully she gets to enjoy it again this year

Dave on 12/05/2012 5:40am

I remeber NIWA last year said that the August snow event was very unlikely to be repeated in 2012. Let us see where the egg lands shall we.
I am all for a higher speed limit in areas that warrant it. I used to have a job that entailed driving 50000kms a year and there were many “back road areas” where I regularly travelled at 130kms per hour. Of course you are right in that “common sense” dictates what should be a safe speed, unfortunately a few drivers are remise in their use of this, hence the so called speed kills motto. It is not the speed but the drivers lack of ability or driving at speed in the wrong place.
Many highways in Europe have cars driving at 130km per hour only to be overtaken by cars travelling much faster, this of course on those great autobahns etc.

Cheers.

Guest on 11/05/2012 8:28pm

I remember the two major snow events from 1992 that hit Canterbury. One in July and one in August. The July one was forgotten a little because Christchurch missed the snow, but the plains and foothill got heaps. Those ’92 events were from two very similar systems (cold air undercutting warm moist air). Both unusual and different to what we got last year. I can’t recall such combinations happening again in such an extreme way. Last Augusts snow was a repeat ‘high / low’ combination that happened in July. The July one was worse for Christchurch, but has been forgotten a bit by the media because it didn’t ‘snow’ in Auckland in July! I also recall in the 1993 winter talk of more major snow events because of what happened the year before. I think it may have been one of the worst winters ever for snow (hardly any)!

Your 40% prediction may be correct. But maybe it has already happened with the one in August backing up the one from July!

sw on 11/05/2012 7:35pm

It be great to have more of august 15ths 2011 (infact more snow) again,this was interesting unlike the usual boring wet and windy cold changes that occur on a weekly basis most of our lives in winter/spring.

GuestMaureen473 on 11/05/2012 7:33pm

I have my fingers crossed for the polar blast and another snowfall.

Ian Cooper on 13/05/2012 6:15am

Phil,

you may be on to it if history is anything to go by. As far as Palmerston North is concerned these events often come in pairs or groups. Going backwards we had 1975 & 77, neither as great as last year in terms of volume. There were two near misses in July 1983 and July 2003 in the interim.

In the late 1930’s there were significant events in 1937 and 1939 and possibly 1934 as well. Before that there was an event in July 1904 that enabled people to build snowmen in the Square, similar to last August. After that there was another big event around the winter of 1912 or 13, I’m still trying to track that date down. Analysis of all of those pairings may show the ENSO pattern was similar to now. It is maybe rare to get similar eevents on consecutive years, but if the conditions are right then watch this space!

Cheers

Coops

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