Seasonal winter forecasts and the stratosphere

Abstract We investigate seasonal forecasts of the winter North Atlantic Oscillation (NAO) and their relationship with the stratosphere. Climatological frequencies of sudden stratospheric warming (SSW) and strong polar vortex (SPV) events are well represented and the predicted risk of events varies b...

Full description

Bibliographic Details
Published in:Atmospheric Science Letters
Main Authors: Scaife, A. A., Karpechko, A. Yu., Baldwin, M. P., Brookshaw, A., Butler, A. H., Eade, R., Gordon, M., MacLachlan, C., Martin, N., Dunstone, N., Smith, D.
Other Authors: Suomen Akatemia
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2015
Subjects:
North Atlantic
North Atlantic oscillation
Online Access:http://dx.doi.org/10.1002/asl.598
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fasl.598
https://onlinelibrary.wiley.com/doi/pdf/10.1002/asl.598
https://onlinelibrary.wiley.com/doi/full-xml/10.1002/asl.598
https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/asl.598
Description
Summary:Abstract We investigate seasonal forecasts of the winter North Atlantic Oscillation (NAO) and their relationship with the stratosphere. Climatological frequencies of sudden stratospheric warming (SSW) and strong polar vortex (SPV) events are well represented and the predicted risk of events varies between 25 and 90% from winter to winter, indicating predictability beyond the deterministic range. The risk of SSW and SPV events relates to predicted NAO as expected, with NAO shifts of −6.5 and +4.8 hPa in forecast members containing SSW and SPV events. Most striking of all is that forecast skill of the surface winter NAO vanishes from these hindcasts if members containing SSW events are excluded.

Similar Items