After almost 6 weeks of producing settled weather the Tasman Sea is today coming to life with a number of active fronts joining together.

The line of cloud, clearly visible on our satellite map, stretches from New Caledonia right down to the Southern Ocean and will deliver torrential rain to the South Island mountains today.

The heavy rain has prompted MetService to advise those planning on visiting the Southern Alps to delay their visit as up to 200mm of rain falls over the next day or so.

All current weather warnings can be found here.

The Tasman Sea has been covered by high air pressure for several weeks blocking category 5 cyclone Hamish from moving towards us last month.  A number of lows have formed over the past 6 weeks in the Coral Sea and north of New Zealand – not one of them has been able to move towards us due to the blocking action of the Tasman Sea highs.

However with limited high air pressure now over the Tasman low ressure is likely to form, sucking down humid air from the sub-tropics.  This is expected to happen over the weekend creating a significant depression and associated rain band.

At this stage WeatherWatch.co.nz believes the rain will move in towards Northland late on Sunday and travel across or near northern regions during Monday.    Its exact path is still unclear but most recent computer models show it moving near Northland, Coromandel and East Cape.

It’s possible the low may move to the north of New Zealand – we’ll keep you posted over the weekend.

The low may also affect racing conditions during the Hamilton 400 on Sunday.  You can check our special Hamilton 400 Forecast page here.

We want to hear from you!  Let us know what the weather conditions are like where you are – even if it’s just your own observations looking out the window.  Be sure to let us know where you’re from – simply post a comment below.