Canterbury could get 'worst snowfall in 20 years'
Canterbury could be hit by the worst snowfall in 20 years this week, weather forecasters are warning.
Blue Skies weather forecaster Tony Trewinnard said up to 20 centimetres of snow could fall to sea level in Canterbury on Thursday and Friday, with up to 40cm above 200 metres and up to 60cm above 400m.
Rain in Canterbury today is expected to ease this afternoon and tomorrow should be dry.
The ground will not have a chance to dry out before more rain hits the region on Wednesday, turning to snow about dawn on Thursday and with ''frequent showers of periods of snow'' continuing through to Friday night.
''We're not so unused to have snow in Christchurch ... but it usually only lasts for six hours or so,'' Trewinnard said.
''To have it potentially last two days is quite unusual and could potentially become quite hazardous.''
Airflow coming from the Ross Sea is expected to cross New Zealand on Wednesday night, combining with a low pressure system moving across the North Island.
The conditions bring the potential for heavy snow, severe windchills and bitterly cold temperatures on Thursday and Friday.
''Potentially we're talking about a very significant weather event, possibly the worst I've seen in 20 years.''
Trewinnard said the weather patterns being predicted were the same as those experienced during Canterbury's infamous snowfall of 1992.
There was still some uncertainty about the forecast given it was three days out, but Trewinnard urged people to start getting prepared for a significant weather event.
''We do have a bit of warning and it would be sad to think that people would come along afterward and say we weren't prepared.
''I would hope that people would think about whether they have to travel on Thursday and Friday and farmers take a serious look at where their stock are and how they would manage stock during a significant snowfall that could last two days.''
At the very least, snow would fall on the Port Hills and the Canterbury foothills ''quite low down'', with severe windchills and freezing temperatures felt lower down in Christchurch, he said.
Saturday is expected to be sunny with light winds, but still experiencing cold temperatures.
Another period of snow showers and very cold southwesterly winds could fall on Sunday but would clear later in the day.