A deepening low over the Coral Sea could bring more severe weather to New Zealand next week warns WeatherWatch.co.nz.

The weather news authority says the low has many of the hallmarks of a developing tropical cyclone however the Fiji Met Service says there is only a low to moderate chance of it briefly reaching cyclone status before it leaves the tropics within the next 48 hours.

The true deepening of the system will take place between New Caledonia and the central Tasman Sea with the storm peaking in strength well away from any land late on Sunday or Monday.

Most models show the low tracking due south into the central Tasman Sea and then tracking closer to the West Coast around the middle of next week – however that tracking completely rests on the strength and location of this weekend’s high, which will be firmly anchored over the South Island.

Head weather analyst Philip Duncan says if the high weakens or starts to move away quicker than expected then this new low could track much closer to New Zealand.  “In light of the stormy weather the North Island has faced this week many are asking about this next system. It’s still a bit too far out to know if it will bring severe weather to New Zealand but rain warnings for the West Coast, Nelson ranges and Mt Taranaki look quite likely next week”.

Mr Duncan says the one positive is that it looks likely to miss Hawkes Bay and Gisborne – and may well help with clean up operations by providing warm, dry, winds for a time next week.

Canterbury and other eastern and southern parts of the South Island will also experience warm winds from the northerly quarter kicking in on Monday and lasting until at least Wednesday or Thursday – putting a temporary end to the wintry weather that has been in place since Anzac Day.

“We are definitely out of the settled weather pattern that has so far been with us for 2011.  We are now in a much more volatile set up and some long range models are picking more sub-tropical lows in the coming two weeks”.

WeatherWatch.co.nz says one long range model is also picking a low which may impact Gisborne and Napier in about 10 days time, but says people shouldn’t read too much into predictions more than 10 days out.  

WeatherWatch.co.nz will continue to bring you the latest news on the sub-tropics as we head into what looks like a a wet start to May.