Each year the MetService aims to detect and warn of at least 75 per cent of all significant wind, rain or snow events.
And each year it outdoes itself, says weather ambassador Bob McDavitt.
This week the weather forecast service came in for a blasting from Far North Mayor Wayne Brown, who blamed it and television news for thousands of holiday cancellations in Northland over Labour weekend.
Mr Brown was scathing of television reports of a "Noah-like storm" that he said were based on MetService information. He demanded an apology from the service, which he argued was ultimately responsible for the negative predictions.
The MetService has denied any wrongdoing, saying its weather warning played down the significance of any wild weekend weather.
Mr McDavitt said yesterday that MetService records showed it was well exceeding its targets for detecting 75 per cent of heavy rain, snow or wind events. In the 12 months to June it had detected 95 per cent of heavy rain events, 87 per cent of severe snow and 94 per cent of severe gales.
Mr McDavitt said the service was also beating other targets, including that no more than 40 per cent of its warnings turned out to be false alarms. There were just 27 per cent false alarms for heavy rain, 29 per cent for heavy snow and 20 per cent for severe gales. "We are doing okay but we want to do better."
Mr McDavitt said the MetService was therefore changing its targets with an aim to achieve in the next four years a minimum 95 per cent prediction of severe rain warnings.
Philip Duncan, head weather analyst at Weather Watch, said he generally found the MetService to be accurate. He said there had been some heavy localised downpours in Northland over Labour weekend but a lot of the rain had fallen out to sea.
Mr Duncan said a problem with people relying on television weather forecasts was that these were "one shot" and once a weather warning had gone out, it was difficult to retract.