Weatherwatch: Storm warnings no guarantee in this tiny land

Sometimes it's as if people want to see storm damage. Photo / Kevin Bone

New Zealanders seem to be getting better at understanding how storms and weather warnings work.

After last weekend's "weather bomb", I was sure forecasters would be hung out to dry by the public, despite the incredible damage inflicted across the lower North Island.

Why? Because big cities weren't badly hit.

It has long frustrated me that if a storm misses a main centre, after warnings for the area, the word "fizzer" is frequently mentioned. People almost seem to want to see death and destruction to justify the warning.

Yet overseas, if a storm misses you and doesn't destroy your house, people appear relieved.

In the US, if a nasty tropical storm misses Florida, it hits Alabama or Louisianna or Texas. In New Zealand, if a storm misses Auckland it will either hit a region such as Northland or the Bay of Plenty, or - more likely - it will hit just offshore where no one can see it.

Our tiny country with its tall mountains makes it one of the hardest nations in the world to forecast - not because we are unsure of what is moving in, but because the terrain can make the weather chaotic.

Perhaps the lack of outrage at the limited damage in Auckland last weekend shows many people are starting to understand the complex nature of forecasting.

The main thing to remember with a warning is simply the word "risk".

It's not a guarantee. No forecaster can predict the weather 100 per cent accurately. But the weather is easier to predict than earthquakes and volcanic eruptions.

Finally, the weather bomb proved one thing. Computer modelling has become mostly excellent for storms. Keep in mind that on Friday, the night before it hit, the storm didn't even exist.

Usually when we predict an incoming storm, we track it on the maps but, in this case, weather forecasters were almost flying blind, relying on models to make the warnings even just a few hours before it hit. That's like landing a 747 jet with a blindfold - and as far as I can see, forecasters made a pretty smooth landing last weekend thanks to those models.