WeatherWatch.co.nz forecasters believe the weather pattern around New Zealand is becoming increasingly unstable over recent weeks – a sign that La Nina is starting to take a firmer hold over our part of the world.

La Nina, which actually means a general cooling of the seas around the equator, creates the opposite effect here, resulting in warmer than average sea temperatures north of us.

It’s these warmer waters which help fuel more rain bearing lows.

In recent days serious flooding has hit Queensland with more on the way – and WeatherWatch.co.nz predicts that the start of 2011 is looking changeable.

“The weather pattern over October, November and the start of December was very stable and very predictable.  Large highs bringing mostly sunny, settled, weather to New Zealand” says head weather analyst Philip Duncan.

But Mr Duncan says the past few weeks have seen those predictable patterns start to slip away.  “Conditions are becoming more unstable, more unpredictable and more chaotic.  Highs are short lived, lows are larger and rain bands are hitting many parts of the country”.

WeatherWatch.co.nz says while some drought affected areas still need more rain others may want less. 

“Too often in La Nina we can see droughts, or dry conditions, disappear almost overnight under flood waters.  Nelson has been an incredibly dry region over the past few months and yet this week it hit the headlines for going underwater.  La Nina can produce these wild card rain events which can have a serious impact on communities”.

The current forecast for the first week of January looks fairly settled according to WeatherWatch.co.nz and MetService, but Philip Duncan jokes we may hear some stereotypical weather forecasts over the rest of summer.  “Forecasters sometimes get teased for having a politicians answer to a straightforward weather question – but I think it’s fair to say some forecasts this summer might be along the lines of mostly sunny and dry with the risk of flooding and gales”.

– WeatherWatch.co.nz

Homepage image: File flooding, Cemil Carki