Most Commented On Story — For the past 18 months global and local climate scientists have been calling for a “High” chance of El Nino forming, many saying it would be as brutal as the one in the 1990s that caused major droughts in New Zealand.

Despite the alarming prediction last summer passed us by with no El Nino.

After 18 months in the media the term “El Nino” has almost developed it’s own persona.  It sounds like the Jesse James of the weather world.

My issue isn’t with the climate scientists thinking El Nino is coming – my issue is with the messaaging that comes with it – the high confidence it will happen…and then 18 months go by and it’s brushed off as ‘it’s still coming’.  Well, we’ve had concerned farmers contacting us for 18 months – some in absolute fear about what El Nino might do to their farm.

We strongly feel at WeatherWatch.co.nz that all this talk is doing little good.

Put it this way – if we thought there was a high likelihood of a low in the tropics forming, and all the models suggested it would reach New Zealand in a weeks time. Do you think it would be crazy, a week before the low formed or even reached New Zealand, to put out warnings specifically talking about which rivers will flood here, and how much they will flood by, and which properties will be affected? It would – because even if the low forms and hits NZ we can’t know where it will be most intense until it has truly already formed.

That’s a little bit like these big El Nino predictions.  The computer models, which are sometimes reliable, sometimes not, suggest El Nino is forming.  But it’s far too early for us in New Zealand to be locking in which regions will miss out on rain and who is exposed to droughts.

This is especially the case in New Zealand where even if we have El Nino (or it’s opposite La Nina) we are just two small, mountainous islands that jut out into the roaring 40s. Anything can happen to our weather – as we’ve seen over the past 18 months.

So until a strong, powerful, El Nino pattern starts to form – it’s very tricky to start predicting which regions would be worst impacted.  General thinking is that eastern areas would be driest – as El Nino tends to encourage more west to south west winds in New Zealand. But if those winds tilt a bit more southerly it could mean plenty of moisture makes it up our east coast too.

To make matters worse, NIWA here in New Zealand (where climate scientists are based) has become commercially aggressive.  Meaning they won’t proactively work with the private weather sector in New Zealand to ensure the public are truly understanding what is happening communications-wise. In fact, WeatherWatch.co.nz has to now contact climate scientists in other nations due to NIWA’s own powerful financial interests here in New Zealand.  A truly terrible set up, one that we have recently raised in a formal complaint with the Minister for CRI’s, Steven Joyce.

So the messages surrounding El Nino will continue – as they have done so for 18 months – with little to no questioning about the accuracy of them, why they are being made, how they are being made, and precisely what it means to the public.

We get forecasts wrong here at WeatherWatch.co.nz – we all make mistakes. Which is why communicating your message is so incredibly important. And judging by the daily comments and questions we’ve had from the public for a full year and a half now, it’s very clear the official communications surrounding El Nino forecasts have failed to make sense while they have succeeded at confusing the public.

WHAT IS EL NINO?
Quite simply, El Nino is a set up when the warmer waters of the Pacific Ocean, near the equator, are blown towards South America and away from New Zealand and Australia.  This creates a large area of warmer than average sea surface conditions in the eastern Pacific – this helps makes more lows which causes rain and floods for western areas of the Americas.  Here in New Zealand and Australia the cooler waters means we have less sub-tropical lows and more highs parked over the Tasman Sea.

It’s the location of these frequent highs (over the Tasman) that can give New Zealand headaches during El Nino.  It encourages more west to south west winds – in turn that puts more rain clouds on the west coast and much drier, windier, weather in the east.  It can then lead to droughts inland and in our east if it continues for several months.

That’s the reason there is concern with El Nino.  

But remember, New Zealand is two small islands in the South Pacific – so even if El Nino forms, our weather can still be varied and changeable. 

 

SO, WHAT IS LA NINA THEN?
The opposite of El Nino. It’s when that warm water gets blown westwards towards New Zealand and Fiji and Australia. We get more humidity, more rain and more tropical cyclones.  La Nina often affects the North Island even more, as it’s exposed to the sub-tropical lows.  La Nina summers can be hot, humid but sometimes quite cloudy.

 

SO WHAT WILL HAPPEN WITH EL NINO THIS YEAR?
Like we said – making definite long range seasonal forecasts is a risky business. For 18 months we’ve seen this.  Our feeling is that for now our weather pattern is quite normal – we’re seeing fairly average weather for the end of Autumn and start of Winter.  Rain has been returning to drought areas – this doesn’t usually happen in a serious El Nino event.

As for later this year, spring and summer – it’s too far to see.  We know there will be tropical storms this summer – we can’t lock in where and what dates.  Same with El Nino – it seems many computer models and climate experts think it’s coming. It may well be. So farmers in the east should have plans in case the rains stop this spring.  In the mean time – we should stop putting “El Nino” in the lime light. It’s like we’re obsessed with something most of us don’t even really understand.  Until we start to see hard evidence El Nino is truly changing the climate across New Zealand this year, our forecast will remain the same: We’re two small mountainous islands in the roaring 40s – anything can happen.

– WeatherWatch.co.nz