Weather watch: Out of the frying pan

Are parts of New Zealand about to go under water? It's may well be a case of out of the frying pan and in to the fire as the third sub-tropical low in a week bombs the North Island with torrential rain - and this one is the biggest of them all, having an impact on the South Island too.

While rain cleared Auckland and other northern centres this morning it's the sheer size of this system that means more rain will return as early as Tuesday, then again on Wednesday, Thursday and Friday.

There are numerous rain warnings currently in place by MetService as this aggressive low quickly deepens and grows in size - by tonight it is likely to be twice as big as this morning and by Tuesday twice as big as tonight.

Without a doubt the droughts are now over as rain tanks overflow - and some rivers too.

This is not want farmers needed - torrential rain on top of droughts. While the rain so far has been great, we're possibly already exceeding what is a "healthy" amount.

The biggest worry I have is the fact that we seem to be jumping from droughts to potential floods. From non-stop highs over northern New Zealand to a stream of sub-tropical lows.

And if you think today's low is the last, you're most likely wrong. The current computer models, which so accurately picked today's low pressure system over a week ago, are now picking another low at the end of this week - and potentially more unstable weather in the northern Tasman Sea heading in to next week.

As El Nino fades away it appears La Nina is coming in. La Nina favours wetter, warmer, winters for the north. This wouldn't be the first time this has happened. In fact Northland appears to be getting a reputation for having just two seasons - a rainy one and a dry one. It seems to be a pattern of recent years that heralds droughts over summer then floods in winter. A small blip on the climate scale but a big one on the local weather scale.

It seems that Autumn has finally woken from its slumber...at least for northern New Zealand anyway. In the South Island Autumn arrived weeks ago.

Apart from Saturday Auckland has had had some miserable temperatures lately - all caused by clear skies at night and a cloudy day to follow.

Clear skies at night at this time of year is a bit like leaving the windows to your bedroom wide open after a warm day... the heat quickly disappears. Then, the next morning, the clouds have rolled in... much like someone turning the heater on in the hallway...but then closing the door to your bedroom stopping the heat from coming in. The clouds can act as a blanket, but it works both ways. At night, it keeps the warmth in... but in the day it keeps the warmth out. When you get out of synch, like we have lately, it's meant cold, clear, nights followed by cloudy days with no warming sun.

So we're in for some rough weather over the coming days - check out our special Storm page with regular updates over the next 72 hours.