MetService meteorologist Clare O’Connor said a trough of low pressure carrying rain would move northwards over the South Island early this morning and would be followed by much colder southerly winds.
"As that cold air cuts under the warmer air, the moisture leads to snow production."
Temperatures were expected to drop to nearly zero in inland Otago and widespread snow forecast to fall to 600m, affecting some higher roads today.
A spokesman for the Queenstown Lakes District Council said snow was falling on the Crown Range, linking Queenstown and Wānaka, this morning and chains must be fitted.
MetService said between 4cm and 8cm of snow was expected to fall on the road above about 800 metres, with lesser amounts down to about 600 metres from 7am until 2pm. Snow showers were possible again from late afternoon and the warning might be extended.
Grit trucks and snow ploughs were patrolling as needed, the QLDC spokesman said.
"All other roads in the district are open, but wet with heavy rainfall in places. We have surface water on roads around Whakatipu and on Haast and Lindis passes."
Road snowfall warnings were also in place for the Lindis Pass (State Highway 8). Between 6cm to 12cm of snow was expected above 800 metres, with lesser amounts down to about 600 metres from 5am to 2pm.
A heavy snow watch is in place for Central Otago northwest of Alexandra including the Queenstown Lakes, also the MacKenzie Basin, with periods of heavy snow above 800 metres, MetService said.
The Danseys Pass Road in Central Otago is restricted to 4WD vehicles (from the gates past the Danseys Pass Hotel) due to snow.
In Southland, up to 5cm of snow was expected to accumulate on Milford Road (SH94) about 800 metres from 4am to 9am today. Snow showers possible again from late afternoon and this warning might be extended.
Heavy rain
Heavy rain warnings were in place for the headwaters of the Otago lakes and rivers today.
Up to 140mm of rain was expected about the main divide, and up to 100mm was expected within 20km east of the main divide until 8am today.
"Further rain is likely during Monday morning and afternoon, but this is likely to fall as snow on the ranges, MetService meteorologist Clare O’Connor said.
"Streams and rivers may rise rapidly. Surface flooding, slips, and difficult driving conditions are possible. Avoid low-lying areas and drive cautiously."
There were heavy rain warnings in place about Fiordland and north of Doubtful Sound overnight as well, where up to 150mm of rain was forecast.
- additional reporting ODT Online
