Long Range NAO Forecast Supports Cold Northeast Winter

This is a long range NAO forecast from the Univ. of Albany. The top image shows the observed NAO values in red, and the forecasted NAO index in gray. The colored lines are separate ensemble members. The bottom line shows the variance, or difference between the ensemble members at any given time in their forecasts. Any spike of gray above that dashed red line indicates that the ensemble members are too far apart to be useful in a forecast.

Looking ahead into mid and late December, it seems that all but 1 ensemble member are forecasting a strong negative NAO. Considering it's only one ensemble member against 3, I support the idea of a deep negative NAO through December. Into January, we see the ensemble members regulate themselves, which seems a little too conservative to me. If Siberia's snow cover in October comes true, the AO will be negative, and the close relationship between the AO/NAO tells me that the NAO is more likely to be negative like the AO will probably be in mid-late January.

February brings the ensemble members going every which way, so I don't feel like it's a good idea to decipher that month until the ensemble forecast members have settled down. Despite this February uncertainty, the other two winter months certainly are looking supportive of a cool and stormy Northeast and general East US.

Andrew