A cold change meeting wet weather coming in from the east is a recipe for blizzard conditions across Central Plateau this Wednesday.

This is the latest update from WeatherWatch.co.nz, who says the blizzard conditions could continue on Thursday and Friday as well.

Motorists and other travellers are being warned to be prepared for possible road closures.

'Data in last night, suggests State Highway 1/Desert Rd could get over 50cms (half a metre) of snow across Wednesday and Thursday. Snow drifts of over 1m are possible near the summit. Closure of the highway looks highly likely if this forecast pans out.

'There is a moderate to high chance SH5 (Taupo-Napier) and *all* highways around Mt Ruapehu will be impacted by snow Wednesday and Thursday.

'If all these highways do close (not saying they will, but if it happens) then the alternative route would be via Gisborne or Taranaki from Wellington to Auckland - in other words, motorists should delay travel until Friday or the weekend - or - bring forward travel to Tuesday or have alternative routes prepared in case snow does shut down these roads for a while.”

WeatherWatch says they're still fine tuning forecasts and will have more details across Tuesday.

'As for the South Island - we expect snow to impact State Highways across the island, including all Alpine Highways, starting as early as tomorrow morning south of Queenstown - but the risk increases across the day and into Wednesday night elsewhere.

'Again, closures are highly likely for a time in our view - or at least significant delays for travellers due to the snow and ice.”

- WeatherWatch.co.nz Travel