G'day terrytnewzealand,
I wrote a post here but it was lost when I tried to submit it. Sigh. I'm only on this site for one day but thought I'd read a couple of threads. So, some quick points.
El Ninos are well understood although the reasons for their appearance is not well understood.
There was an El Nino until a few months ago. Over the past few months the phenominum degraded rapidly. For the last two or three months La Nina has been set up. The probability of a La Nina event is now very high. While it might not come about the El Nino cannot come back for a while simply because of the physics of the movement of the large body of cold water across the Pacific.
La Nina, typically causes much lower world temperatures, is very good for Australia and much of Asia but not at all good for the Western US, where it causes droughts and an increase in tornados in the mid west.
La Nina's have a much longer term influence over much of the world than El Nino. If the La Nino event does occur then it is likely that the next northern hemisphere winter is going to be a cold one. The whole prediction of a record year for 2007 goes out the window with a La Nina. What the Hadley centre does not mention in the BBC article is that there is a very big difference in worlds temperatures for 2005 and 2006 between the SAT and the satellite data. Me? I trust the satelite data much more than the SAT, where the calculation of averages are now being changed sometimes more than once in a single year in some parts of the world.
Unlike 1998, which was a very hot year whether you use Satellite, balloon or SAT data, 2005 and 2006 were far less hot according to the remaining balloon data and the satellite data than from the Surface Air Temperature Data.
So 2007? End of drought in Eastern Australia if La Nina locks in. A very good chance based on on what is currently happening of high autumn (fall) rainfall.
Predictions based on what El Nino or La Nina over more than a couple of months in advance are about as good as predicting whether it will rain six or seven days in the future. Next to worthless.
Richard