MetService has gone all out predicting what they call a “significant” snow storm for the country this Sunday and Monday – but confusion remains over just how low it will fall with snow not predicted by them in any of their main centre forecasts apart from Queenstown.

“According to MetService, this polar outbreak is likely to bring gale force winds, as well as snow showers to very low levels, to southern and eastern parts of both islands on Sunday or Monday” they said in a press release yesterday.

In their severe weather outlook they also posted “moderate confidence” of snow warnings being issued across two thirds of the South Island and a significant chunk of the lower North Island, one of the more widespread snow predictions they’ve made.

However the word “snow” isn’t actually used in any of their forecasts for Invercargill, Dunedin, Christchurch or Wellington, meaning some confusion on just how much snow will fall and to how low.

Computer models are struggling with the snowy forecast and WeatherWatch.co.nz forecasters say there is still too much confusion to be certain of heavy snow to low levels.  “Some models have a high moving in, others have the complete opposite with a low off the east coast driving in bitterly cold south easterlies and snow to sea level” says head weather analyst Philip Duncan.

He says the ingredients are definitely there for a snow event but there are a couple of factors stacked against it.  “Two of the models we rely on predict a high moving in, which would push the snow storm out over the Chatham Islands instead.  Another model, perhaps one that is considered more reliable, is predicting snow to very low levels.  As you can see it’s quite a tricky forecast”.

Weather anayst Richard Green says the computer models are flip flopping on the chance of snow showers for eastern parts of NZ late in the weekend and on Monday and he says it seems that much of the moisture will be east of New Zealand “however the cold southerlies should still feel very cold and some showers may have a wintry mix”.

“We’re keeping an eye on this one, other forecasters have predicted significant snowfalls and at one point yesterday it looked likely but today it’s a slightly more marginal call”.

Snow storms in New Zealand can be very tricky to predict too far in advance and while it’s fairly common for computer models to disagree on weather forecasts it is a little unusual to see such huge differences between the international models over something so potentially significant.

WeatherWatch.co.nz predicts a cold change on Sunday and Monday which could see snow to low levels but confidence remains low at this stage of anything too severe.

We will be monitoring this very closely and will bring you updates as our confidence increases or decreases of this snow event.