Heavy snow, heavy rain, big swells and isolated thunder are expected to storm over New Zealand as a giant low-pressure system crosses the Tasman Sea.
"For the next three days, low-pressure systems will approach and pass across New Zealand," WeatherWatch says.
"This will lead to heavy snow in the South Island mountains and hill county, heavy rain and isolated thunder into coastal parts of the western North Island and heavy rain around the South Island too."
- Weather: Serious dumping of snow for the South Island this weekend
- Weather: Heavy rain and wind on the way, possible thunderstorms
- Weather: -10C polar blast, sea-level snow warning for South Island
MetService says the largest accumulations of rain are forecast between Christchurch and Dunedin, while WeatherWatch warns 100mm or more of accumulated precipitation is partially expected until Monday.
After the weekend a cold blast will drive in big swells and cause temperatures to plummet.
"Wind-chill at times over the next few days will be tough on newborn lambs and calves," WeatherWatch says.
Auckland and Northland are expected to be hit by up to six-metres of significant wave height (SWH) - the average height of the highest one-third waves - from Sunday afternoon to Tuesday morning on western beaches.
Six-metres or more of SWH is expected over Southland and Otago from Tuesday noon to Wednesday noon.
"Large swells will also build on Wednesday around Cook Strait and may affect some ferry services, but not yet locked in," WeatherWatch says.
Snow is likely to fall down to 300m, with over a metre expected until Sunday at higher elevations.
"This snow event will likely have a big impact on travel down south this weekend, and MetService has issued eight road snowfall warnings for the South Island," MetService says.
Newshub.
