MetService has updated its latest forecast in Otago and Southland to a severe weather watch for heavy snow in parts of the regions.
Meteorologist Peter Little said a trough was forecast to affect the west of the South Island this morning through to early tomorrow morning, bringing northerly rain to the West Coast with some heavy falls.
In addition, a cold southerly change is forecast to spread north across the South Island early on Tuesday and into Wednesday afternoon, bringing snow down to 300m to 400m in the far south, and to 500m to 600m across the upper South Island.
Mr Little said there was a strong possibility that snow could fall to 300m in the Dunedin hill suburbs on Wednesday.
"Regardless of snow, it's certainly going to be very cold.''
Heavy snow is predicted to fall in Central Otago, the Southern Lakes District and inland parts of Southland from 3am Tuesday to 4pm Wednesday.
"Significant snow may fall above 800m, affecting the higher roads and passes, and this watch also covers the possibility of snow accumulations reaching warning criteria about and above 600m in some places.
"People are advised to keep up to date with the latest forecasts in case parts of this watch are upgraded to a full warning or further areas are added.''
He said a second front was forecast to go through on Friday, but at this stage, the snow was not expected to drop below 500m.
MetService meteorologist William Nepe yesterday urged farmers to be prepared by moving stock to lower, more sheltered areas, and asked drivers to be wary of passes and roads in higher areas around the region.
Meanwhile, snow showers were expected to affect the higher parts of the Milford Road (SH 94) on Tuesday morning, with up to 3cm of snow settling near the tunnel, the NZ Transport Agency advised.
