Forecasting the North Atlantic Oscillation Using Pacific Surface
Pressure
Gidon Eshel
Monthly Weather Review, Vol. 131(5), pp. 1018-1025, May 2003
Abstract
A statistical forecasting scheme for the North Atlantic Oscillation
(NAO) is presented. The forecasts are based on Pacific surface
pressure. With 21 months lead time, skills are significant and useful
but modest. At 15 month lead, forecasts are robust and skillful under
stringent cross-validation, and further improve at 12 month
lead. Cross-validated 1 yr forecasts correlate with 1925--2002
observations at $\sim$0.45. Other performance measures indicate
similar skills, outperforming the best autoregressive models of the
NAO Index. Importantly, skills of North Pacific--based forecasts
easily exceed those of North Atlantic--based ones using identical
machinery. The results suggest that NAO variability is not exclusively
internal to the North Atlantic, but is also a response to upstream
forcing from the North Pacific.