Weather Watch: High and dry

January has been drier than average. Photo / Sarah Ivey

It's possible we may see a tropical storm, or even cyclone, form north of New Zealand this week - but at the same time high pressure is going to hold over us - bringing dry, settled weather for most.

The predicted low north of New Zealand is going to form around the New Caledonia / Vanuatu / Fiji area - are large area to focus on.

Will this low bring in more much needed rain to northern New Zealand? Potentially. How likely? I'd say "low chance this week but higher chance next week". Lows coming out of the sub-tropics tend to drift towards the south east. That means the location of the low north of us makes all the difference on how much rain we'll receive.

With such a large area at an "increased" risk of a deep low forming in the next 7 days it means three scenarios are likely.

One - with the large high over us it will stop the low in its tracks...
eventually the low will use up all its energy and fall apart.

Two - the low forms near to Fiji - and when it does drift south, it will be well east of New Zealand bringing no rain at all.

Three - the low forms nearer to New Caledonia, putting it in the higher risk category for NZ, and increasing the chances of heavy rain (and wind) next week.

Whatever the eventual outcome though, the high and low will combine to create an easterly flow over the upper North Island (Waikato to East Cape northwards) this coming week.

Take a look at the long range maps here (10 days).

Unless this low moves in over the next 10 days January is shaping up to be drier than average for many regions, regions that should be average or wetter than average during La Nina conditions.

Meanwhile across the Tasman, La Nina is living up to all expectations with more rain pushing in to Queensland and other parts of Australia. Heavy rain is also pushing in to the north west and may even push in to the desert.

At the moment, on any given day, the usually very dry continent has at least two or three lows pushing in and bringing rain - to all four quarters and inland. For a nation that is several times the size of us and so close to us it really shows how tricky the weather can be when they are having so much rain and, for the most part, we are missing out.

For this week at least, New Zealand will remain in this isolated bubble of dry, high air pressure but this low to the north will certainly be one to watch.