Weather works in patterns, and it is just they way they have patterning out in the last few weeks that have resulted in dramatic circumstances in western regions over the North Island especially.
Yes, also Sea temps in the Tasman are a little warmer currently, will aid general instability.
Might be in for a Thundery Spring.
These warmer seas in the Tassy, this, with the colder water down south, should give interesting weather this spring, if the current weather pattern continues.
re dargaville comment if the wind had of been from the west it would have pushed the tide much higher it is just the way the harbour is set up they would have had a large storm surge aswell as the swollen river. witch in theroy would have pushed the river over its banks so thats why i say the SE or SSe winds helped save it plus the fact that the baro was on the rise witch i failed to mention in my previous post.
Wildland wrote: If I had the time, I'd chart the various events to see what their frequency looked like compared with contemporary events. One day...
A couple of years ago (and it was just 2 or so) NIWA published a study of heavy rainfall events from the NZ climate archive which showed no trend towards an increase in the frequency of heavy rainfall events somewhere in New Zealand over the last 100 years. Of course, thats not to say that some places in the country are not getting more frequent extreme events, but taken over all, nope.
I've tried, but cant find, any reference to that research on the NIWA site. Are there any NIWA lurkers out there who can help us with a link please?
Of interest to me is the duration of the warm (positive?) phase of the PDO (or IPO), which started in about 1977. It looked as if it was going to flip around 1998-2000, but that didn't happen. Assessments of volatility and ideas of the possible effects of warming on the PDO or ENSO indices will be interesting to revisit in another 10 years. Meanwhile, those who rush to decry any suggestion that warming is playing a part in climate events risk looking a bit foolish if they push too hard.
Have just received Weather & Climate 27 (May 2007). First paper on pages 3-44 is "Changes in New Zealand daily rainfall extremes 1930-2004" (G M Griffiths).
I think it will be very interesting to see if an another 5-10 years' worth of data changes anything.
To me a big issue is whether the effects of large rainfalls have worsened because of land use practices - that certainly seems to be true in the UK and Europe, let alone countries like the Philippines and Indonesia, say.