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It is much more difficult to predict the NAO/AO state months in advance.  Unfortunately this climate mode is "noisy" meaning that you can see extreme values and we can't see them coming well in advance.  With that said there is a *small* predictable signal in the NAO/AO that is related to ENSO.  What research says is that La Nina tends to be associated with a stronger polar vortex (positive values of NAO and AO).  So a weaker polar vortex seems less likely this coming winter.  With that said, I want to emphasize that this is a small signal and can be easily be wiped out if there is, say, a sudden stratospheric warming (SSW).  Unfortunately SSW are not predictable more than 1-2 weeks in advance.