Storm clouds are building in the Tasman Sea today ahead of what could be several rough days of weather.

WeatherWatch.co.nz head weather analyst Philip Duncan says torrential rain and gales are expected in the South Island over the next 72 hours with perhaps even more rain and strong winds for the North Island next week.  “We have a low dropping down through the Tasman combined with a blocking high east of the South Island – the two will combine to bring gale northerlies and torrential rain to some parts over the next 3 days then another possible low next week in the north”.

South Island

Mr Duncan says the entire West Coast of the South Island is in for a drenching starting later today and setting in during Thursday.  Government forecaster, MetService, is advising those considering venturing into the mountains to “reconsider or delay their plans as conditions are likely to be hazardous”.

Gale force winds are also likely to hammer some areas, although most populated places may miss the worst.  Still, WeatherWatch.co.nz says residents in Southland, western parts of Otago and inland and southern Canterbury, which includes Invercargil, Gore and Queenstown, should be well aware of the predicted strong winds. 

Rivers flowing through Canterbury and Otago may also receive a significant boost from heavy rain on the West Coast “spilling over”.

North Island

It’s not just the South Island that’s in the firing line for rain.  WeatherWatch.co.nz’s long range forecasts show the potential for a sub-tropical low early next week.   “The computer models we use are consistent with their predictions of a decent rain bearing low coming towards Northland, Auckland and other northern and western parts of the North Island around Monday and Tuesday next week” says Mr Duncan.  “We’ll have a better idea towards the end of this week as to how much rain will fall and where”.

Mr Duncan says if the forecast rain eventuates it will be good news for farmers, gardeners and those relying on rain water tanks.  “We went from a drenched February to a parched March.  So far the first half of April has been very dry too.  Rain is needed in many areas”.

However rain may not make it to the region that needs it most – Hawkes Bay.  The region is sheltered by the Hawkes Bay ranges and Central Plateau from rain moving in from the north west.

Warmer for all New Zealand

Northerly winds are expected to prevail for much of the North Island this week bringing warmer weather.

Mr Duncan says overnight lows in both islands will be “well above” where they were this time last week with no signs of frost.