The fine art of weather forecasting

Well it was a busy weekend on the weather front with snow, thunder and severe gales recorded across both islands.

The storms highlights were:

- Winds over 150km/h (hurricane force) around Stewart Island and the lower North Island.

- Heavy snow in Queenstown, Timaru and Christchurch.

- A number of roads closed due to snow.

- Flights cancelled in Queenstown.

The nature of this storm caught some forecasters off guard. MetService didn't predict snow in Timaru and only added Christchurch in once the sleet had turned to snow flakes. The Radio Network's new Weather Watch Centre, where I work, was bang on with most of its snow forecasts and predictions (but of course I'd say that!), oddly enough we use computer models from a company called weather.com, based in Atlanta, Georgia, and they forecast Timaru's snow last Wednesday, which I thought was pretty impressive!

But I have to admit I did get one thing wrong... I didn't think it would rain as much as it did during the All Blacks game in Wellington...I think I called for a few showers. Whoops.

To me, getting a forecast wrong isn't bad so long as it doesn't happen often and so long as you explain why it was wrong. With my Wellington forecast I didn't expect the cold front to suddenly speed up and arrive in the Capital as quickly as it did. I admit I got it wrong...and I'll learn from that!

MetService has, in my eyes, improved a lot with their weather warnings. Their day to day forecasts are a little too 'generic' for my tastes...using blanket words such as 'rain' when perhaps it's really only a few patches of rain otherwise dry. But their weather warnings are getting more and more accurate... and I think their real feather in their cap are their severe thunderstorm watches which they have online. Something to check out this winter when we start seeing more violent storms.

Blue Skies, a forecasting company based in the South Island, seem to have a good grip on snow forecasts over the South Island. I haven't done much research but from what I've seen, they're pretty clued up to picking up snow storms several days out.

Ken Ring is another guy that get it's right quite often. A lot of meteorologists dismiss his forecasts - which he prepares a year in advance using the moon cycles. They don't believe the science has merit. Again, I haven't done my research but I've heard he gets a lot of forecasts right...and several months in advance is pretty impressive.

Some people say to me, anyone can predict New Zealand's weather. "You're safe if you say this week we'll have a few showers and fine breaks"... chances are they'll be right more than half the time.

Is there room for improvement with our weather forecasts? Oh yes, definitely. Are we reactive enough to change? Not at all. Do forecasts admit when they get it wrong? Not by a long shot. Do people trust the weather forecasts? Probably not as much as they should.

It's these reasons that prompted me to set up the Weather Watch Centre. Through our radio news station Newstalk ZB...and through web readers here at the Herald Online we can bring you regular weather news updates...bringing the excitement of our country's extreme and incredible weather directly to you in a way that's never been done before. We update as the weather changes. We'll admit if we get it wrong - and most importantly learn from those mistakes.

The week ahead is looking a lot quieter than the weekend... cloudy and cold in the South Island... cold nights and settled in the North with milder days. And strong winds across Southland and coastal Otago.

Philip Duncan

For more information see the Newstalk ZB weather website or the NZ Herald weather section.