Update 8:55am — A weather bomb near Stewart Island has narrowly missed hitting NZ directly but heavy rain, squalls, thunderstorms and some of the biggest seas on the planet around New Zealand.  Snow to low levels in the Deep South is also predicted along with the chance of isolated tornados and waterspouts along the western coastline.

WeatherWatch.co.nz says the centre of the low is just missing New Zealand, which is some good news.  “This is a nasty storm and if we plonked the current weather map over the tropics you’d swear you were looking at a tropical cyclone” says head weather analyst Philip Duncan.  “However it’s anything but tropical with cold air at its core and it will help dredge up some very cold air from well south of New Zealand”.

Mr Duncan says most of the energy from this system will be targeting rural and less populated parts of the country however southern and western areas of both islands will be most exposed to the rough and sometimes dangerous weather.

WeatherWatch.co.nz predicts Bluff, Oban, Riverton, Gore, Mataura, Invercargill, Queenstown, Dunedin, Hokitika, Greymouth, Westport and New Plymouth are likely to be the centres most exposed to the rough weather, but residents across the lower two thirds of New Zealand at least should be up to date with the latest weather news and warnings.

“It’s not all doom and gloom – some areas in the north and east will see the sun this week too as the main ranges in both islands help shelter eastern and north eastern areas from the worst of the weather – however as the week goes on eastern areas will see the cold wind and showers move in too”.

Winds:
There are three factors contributing to winds across New Zealand on Tuesday.

One – there is a big air pressure gradient between this deep low to our south and a big high over Australia.  This means most of the country will have windy weather at some point this week.

Two – the centre of the low itself is so deep that damaging winds wrap around the centre of it – just as they do with tropical cyclones.  And just like a cyclone the low is so tightly packed that the worst of these winds will remain around the centre only, which will remain offshore – however Stewart Island is in the firing line, as is coastal Southland.  This threat has already eased and MetService has cancelled wind warnings (as of 8am),  It only narrowly missed Stewart Island.

Three –  squalls along the west coast of both islands today may produce localised damaging gusts in sudden downpours.  Some of these downpours with have thunderstorms and may even produce localised damaging tornados and waterspouts.

Snow
Snow is expected to low levels across Southland, Otago and Fiordland on Tuesday and especially Tuesday night and Wednesday morning.  Snow may fall to sea level (along with thunderstorms for Southland which may also produce heavy hail). 

WeatherWatch.co.nz predicts a high chance of snow in Queenstown over Tuesday and Wednesday and a high chance of snow on Dunedin’s hill suburbs and also in Gore and surrounding communities. 

A moderate risk is in place for snow in Invercargill and to sea level in Dunedin.  The predicted temperatures currently support this.

At this stage no snow is forecast for Christchurch.

And it’s not just the South Island exposed to snow – WeatherWatch.co.nz says there is a moderate to high chance of snow on the Desert Road across Tuesday, Wednesday and early Thursday – motorists driving through Central Plateau and on any Alpine Highways in the South Island should carry chains or be prepared for detours and road closures.

Flights – Updated
WeatherWatch.co.nz says Invercargill and Queenstown airports may well have flight delays and cancellations due to snow.  Please check with your airline and airport websites for more information.

Huge Swells
Across Tuesday huge seas will quickly spread up the entire west coast of New Zealand, reaching Taranaki today and Waikato, Auckland and Northland later today and into Wednesday.

Weathermap.co.nz predicts swells of 6 to 8 metres at sea.

According to their swell maps the areas of largest swells around New Zealand is the biggest on the planet.

“This is not the day to go surfing” says WeatherWatch.co.nz weather analyst Philip Duncan.  “Not only will the waves be several metres high in some areas, but strong to gale force winds will be travelling with the waves.  It will be messy, rough and extremely dangerous”.

WeatherWatch.co.nz says to make matters more dangerous, thunderstorms and the chance of waterspouts are also in the forecast from Taranaki southwards along the western coastline for Tuesday.

Light at the end of the tunnel
So where to from here?  This system will bring a windy and cold week to New Zealand however conditions are still predicted to ease by Friday says WeatherWatch.co.nz.  The weekend is currently looking mostly settled and calm with frosts in sheltered areas of both islands.

Make the most of it – the next big low may arrive at the start of next week…just in time for the school holidays.

– WeatherWatch.co.nz

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What are conditions like where you are today?   Post a comment below!