WeatherWatch.co.nz weather forecasters are continuing to monitor a developing low in the Coral Sea north west of New Zealand where a tropical cyclone is expected to develop by the end of the week or weekend.

Head weather analyst Philip Duncan says the tropics have “roared into life” in the past few days and long range models indicate there will be plenty of activity north of us over the next few weeks – but will any of the rain reach New Zealand?

“By next Monday there could be as many as four tropical lows north of New Zealand, one likely to be a tropical cyclone. But despite all this mounting pressure to bring rain, to northern New Zealand especially, the highs over us maintain the strength to hold back these plump rain makers”.

“However as we head through March the highs over us will dip further south – that opens up the increased chances of rain moving into northern New Zealand”.

As for the cyclone, the long range models remain conflicted.  The most trusted cyclone data we have suggests the cyclone will drift down the Queensland or even New South Wales coastline(s).  However yesterday afternoon the models were picking this then ex-cyclone would reach New Zealand in about 10 days time.  This morning, unfortunately for many, the models have again backed off from that scenario.

“Computer models have been flip flopping a lot more lately as they try to pick the rain makers out from the large highs – this is a tough weather pattern we’re in.  In every case it’s a battle to see who will win, the high or the low – and so far this year the highs have been winning almost every fight.  The law of averages says this can’t continue forever”.

But in the short term the nation looks very dry.  Rain that was possible next week now looks as though it will fall painfully close to New Zealand, but out at sea.  A trend that has started to form as the tropics start to wake up.

However the cracks around our stubborn highs continue to grow – with showers likely creeping into regional forecasts more and more over the coming weeks.

As for the cyclone – WeatherWatch.co.nz says those in eastern Queensland and coastal New South Wales should monitor forecasts very closely – as should New Zealanders keen on rain, however as of this morning the chance of the cyclone reaching New Zealand was still considered low to moderate – or about 30% – and that also goes for the chances of much needed substantial rain. 

– By Head Weather Analyst Philip Duncan, WeatherWatch.co.nz