Hey john, we all know that when we have a "El nino" it is bad for winters here in northern Illinois and when there is a "La nina" we should have good winters for us snow lovers. Our local meteorologist out of Chicago (whom I think you have worked with)talks alot about the "La nina" and how it is responsible for all this snow and colder than average temps this year. So my question is, what are the chances of the "La nina" forming again next year? or the chances of a "El nino" for that matter and what is the driving force behind them to make them cool or warm the ocean?

There is always the chance that it could hang on, but multi-year La Nina's are rare and the official forecast is for this current La Nina to gradually weaken over the next 6 months, with the potential for an El Nino next winter.

Of course the forecasts for El Nino and La Nina have not always proven to be very reliable.

As far as the driving force goes, it is not fully understood what makes the sea surface and other variables in the equatorial Pacific fluctuate like they do. However, it is noted that the ocean and atmosphere do tend to feed off of each other with these events.

-John

Then when is it ever neutral?

Also, if it is zero degrees today and tomorrow is to be twice as cold, how cold is it?

xsledder-

The ENSO index spends much of it's time in the neutral zone (+/- .50), I think it is just a case that when it is neutral, no one talks about it.

As for your second question it would depend on if you are using the fahrenheit or celsius scale.

-John