The study of El Nino and La Nina is in its infancy. But clearly El
Nino and La Nina have effects that extend far beyond the Pacific.
What those effects are remain to be clarified.

As for this past winter....well it certainly was unusual. Maybe the
best that can be said is that a strong La Nina is likely to produce
less "ordinary" weather in far flung parts of the planet - expect the
unusual and there won't be disappointment.

I draw a parallel. In my youth, plate tectonics was scarcely
understood and was little more than a hypothesis. I am sure that El
Nino and La Nina phenomena - scarcely understood today - will be as
mainstream 50 years from now as plate tectonics is today.

Jack