Forecasting Canterbury’s 1992 snowstorm

The anguish, sorrow, grief and distress expressed by farmers in a community meeting after Canterbury’s 1992 snowstorm is something weather forecaster Tony Trewinnard (pictured), of Blue Skies Weather, will never forget. It was the turning point in realising better communication methods, for weather forecasting, were urgently needed. 

On August 28 1992 Cantabrians awoke to a snow-blanketed region, which weather forecasters began broadcasting alerts for at midday on August 27, announcing heavy snowfall from that evening. Little warning for what was the worst snowfall in 30 years with many farmers in the thick of lambing, causing the loss of one million ewes and lambs and costing farmers $40 million (equivalent to $70m today).

Extensive power outages occurred, with linesmen taking several days to reach some rural areas to restore services. Christchurch Airport was closed, as were many roads and schools closed. Hospitals remained open for the Red Cross.

Hay was transported from other parts of New Zealand and the government covered road-user charges incurred by transporting and delivering supplies.

At this point, Trewinnard had been running Blue Skies Weather for about five years and had built a small but appreciative group of farmers who received regular forecasts through direct communication from Trewinnard’s computer via fax. He had been able to provide enough warning and lead time for those farmers to make preparations.

But many farmers were simply left unaware, especially if they missed the radio daily rural weather update or the evening news. “There was no such thing as the internet, newspaper forecasts were a day old, and there were no weather apps on your phone because your phone was attached to a curly cord in the kitchen.” Trewinnard says the 1992 snow event is the yardstick for the current and previous generation.

In late 1992 he attended a meeting with local farmers organised by The Press Editor David Wilson. It was clear the feeling of loss was deeper than lost dollars, it was the emotional impact of losing so much stock, and the fact it all happened without warning. “Farmers come across as pretty tough people, portraying that Grizz Wyllie image. At that meeting it was very clear that these tough farming people felt deeply and emotionally,” he says.

It was decided that evening that a better way to communicate weather forecasts to farmers was needed. Within a few months, a dial-up telephone service called The Press Weatherline was born. Blue Skies Weather was the provider of local forecasts, all funded by The Press. “Over time, this phone line became extremely popular, with tens of thousands of calls per month in the winter season as farmers sought as much warning as possible for future snowfalls.”

Eventually the service became part of The Press Infoline, which provided a whole range of local information to Christchurch and Canterbury residents via telephone.

Trewinnard says farmers are increasingly savvy, using accurate long range weather forecasts to make the best business decisions. “Farmers can treat a ‘warning’ as a throwaway comment, or think of it as a serious input to help the business.”

Today, this is becoming more and more prevalent with a challenging economic climate where every decision and dollar counts; where farmers are willing to pay for accurate time-scale information and rainfall predictions.

Being small narrow islands, forecasting in New Zealand can be challenging, but Trewinnard said the quality of forecast delivery has improved significantly. “Our short-term forecasting has certainly got better, and the four to five-day forecast now is similar in accuracy to what the three to four-day forecast used to be.”

As forecaster he provides the information, which gives opportunities to farmers to make smart decisions, based on their own knowledge and experience. The capability to confidently forecast six weeks ahead for weather and six months ahead for climate, is a big part of his business now. Most of his new client inquiries are forecasting on these time scales, especially for seasonal planning for corporates.

Trewinnard has got over the nervousness of not getting the forecast right, and enjoys the thrill of living on the edge, hopefully seeing the weather manifest, verify and come right. “My favourite part of the job is being able to see how the forecasts pan out over time.

“I think the fact we haven’t seen lamb losses on the scale we saw in 1992 is a pretty sure sign we have moved in theright direction. Weather forecasting is better in value, the farmers’ use of it, and the quality.”