loading page

Underpredicted ENSO Teleconnections in Seasonal Forecasts
  • Ned C Williams,
  • Adam A. Scaife,
  • James A Screen
Ned C Williams
University of Exeter

Corresponding Author:[email protected]

Author Profile
Adam A. Scaife
Met Office Hadley Centre
Author Profile
James A Screen
University of Exeter
Author Profile

Abstract

The El Niño-Southern Oscillation (ENSO) influences climate variability across the globe. ENSO is highly predictable on seasonal timescales and therefore its teleconnections are a source of extratropical forecast skill. To fully harness this predictability, teleconnections must be represented accurately in seasonal forecasts. We find that a multimodel ensemble from five seasonal forecast systems can successfully capture the spatial structure of the late winter (JFM) El Niño teleconnection to the North Atlantic via North America, but the simulated amplitude is half of that observed. We find that weak amplitude teleconnections exist in all five models and throughout the troposphere, and that the La Niña teleconnection is also weak. We find evidence that the tropical forcing of the teleconnection is not underestimated and instead, deficiencies are likely to emerge in the extratropics. We investigate the impact of underestimated teleconnection strength on North Atlantic winter predictability, including its relevance to the signal-to-noise paradox.