It appears Mother Nature might be on time this year, bringing a good dumping of snow for many parts of Otago and Southland for the start of winter.
MetService meteorologist Peter Little said a strong and cold southerly flow could bring snow to the ranges of the South Island during Saturday and early Sunday.
It was possible it could fall as low as 500m over the weekend, he said.
"It will affect some of the higher parts of the southern region, and potentially some of the higher passes.
"So if people are travelling this long weekend, they may have to be aware that the roads could be affected.''
Weatherwatch.co.nz said Queenstown, Cromwell, Lumsden and Te Anau were all in line to get a dusting of snow on either Friday and/or Saturday.
Little said the snow was particularly good news for the opening of ski fields this weekend.
"Ski fields will be getting a decent dump of snow.
"There's really been very little snow so far. This is the first significant dump of the year.
"It's really perfectly timed.''
He said temperatures in much of Southland and Central Otago were forecast to reach a high of 6-7degC on Saturday, and could drop as low as 0degC over night.
It was expected to be a couple of degrees warmer on Sunday.
Around Dunedin and coastal Otago, the high was forecast to be 8degC on Saturday and 10degC on Sunday, dropping to a low of about 4degC overnight.
Monday looks set to be fine across the region but a return to cold and showery conditions is expected next week.
Meanwhile, rain has flooded parts of State Highway 6 on the West Coast, and prompted the Westland District Council to activate its Emergency Operations Centre, RNZ reports.
The region has also been pelted by hail and was hit by nearly 6000 lightning strikes overnight.
The NZ Transport Agency is asking drivers to slow down if they are travelling between Ross and Haast, where water has accumulated across the road, and to expect strong winds and surface water on SH 73 through Arthurs Pass.
Canterbury Regional Council is warning people to stay away from the region's riverbeds and tributaries after the heavy rain in Westland and across the Southern Alps.
Rivers including the Rakaia, Waimakariri and Waiau are expected to rise sharply throughout the day and into the evening.
However, Westland Mayor Bruce Smith said despite the concerns for Canterbury the rainfall does not appear to be affecting rivers on their side of the Alps today.
The Waimakariri River.Heavy rain may raise water levels in the Waimakariri river and two others, the Canterbury Regional Council is warning. Photo: PHOTO NZ
MetService said residents should keep an eye on the severe weather, which isn't expected to ease up until early tomorrow.
Peter Little said it is not as severe as the weather event that washed out the Waiho bridge in March, but is still significant for the region.
He said the heavy rain could lead to a rise in river levels, both on the West Coast and in parts of Canterbury.
A heavy rain warning has also been issued for the Tararua Range and Mount Taranaki in the North Island tomorrow.
- additional reporting RNZ
