Weather Watch: Media got it wrong

In New Zealand, the only authority for tsunami warnings is Civil Defence. Photo / Thinkstock

Just after seven on Thursday morning I was alerted, via text message from Civil Defence, that a tsunami warning had been issued for New Zealand.

I scrambled to get a story up on WeatherWatch.co.nz and quickly checked in with nzherald.co.nz for the latest developments.

But it didn't take long for confusion to set in. Warnings were issued, warnings were cancelled, and many in the media and public were scratching their heads trying to work out which warning was current and which was not.

In New Zealand, the ONLY authority for tsunami warnings and cancellations is Civil Defence. But media were taking reports from two sources - Civil Defence and the offshore Pacific Tsunami Warning Centre (PTWC).

The warning centre is a government body that provides warnings to assist local authorities (such as Civil Defence). So while it's okay to initially report if the centre has issued a tsunami warning, the media should then only report on Civil Defence advice, once Civil Defence has activated - this way we avoid mixed messages like we had on Thursday.

Speaking of accuracy, a retired pilot has been assisting me with our forecast accuracy and reminded me that forecasting is all about timing. The timing of weather forecasts, he points out, is almost as important as the forecast itself.

We know when rain is coming. We know when highs are coming. But we consistently get the timing out - and when I say "we" I mean all forecasters.

His theory is this: we know that rain falling in the mountains will eventually reach the coast - but timing that surge can be tricky. It's the same with predicting a front. We know it's moving towards us, but the exact timing of when that rain band will hit can be tough for weather forecasters.

With forecasting, if we predict rain to arrive in the afternoon on Thursday and it arrives four hours later, the day can go from being a "wet" day to a "dry" one.

So we're taking this on board and are now placing a bigger focus on timing.

We also plan to expand weather forecasts in other areas later this year. WeatherWatch.co.nz currently provides weather forecasts for Auckland only.