Multidecadal Variation in the Seasonal Predictability of Winter PNA and Its Sources

Based on reanalysis and ensemble hindcasts data, this work investigates the multidecadal variation in seasonal predictability of Pacific-North American (PNA) teleconnection pattern during winter its sources. The results show that at two ends 20th century, PNA is mostly driven by El Niño-Southern Oscillation (ENSO), a good prediction expected if models can accurately predict PNA-ENSO relationship. During middle not only ENSO but also closely linked to Pacific Decadal through air-sea coupling process extratropical North Pacific. Improvements require both relationship northern