TY - JOUR
T1 - Seasonal Predictability of the Winter North Atlantic Oscillation From a Jet Stream Perspective
AU - Parker, Tess
AU - Woollings, Tim
AU - Weisheimer, Antje
AU - O'Reilly, Chris
AU - Baker, Laura
AU - Shaffrey, Len
PY - 2019/8/28
Y1 - 2019/8/28
N2 - The winter North Atlantic Oscillation (NAO) has varied on interannual and decadal timescales over the last century, associated with variations in the speed and latitude of the eddy-driven jet stream. This paper uses hindcasts from two operational seasonal forecast systems (the European Centre for Medium-range Weather Forecasts's seasonal forecast system, and the U.K. Met Office global seasonal forecast system) and a century-long atmosphere-only experiment (using the European Centre for Medium-range Weather Forecasts's Integrated Forecasting System model) to relate seasonal prediction skill in the NAO to these aspects of jet variability. This shows that the NAO skill realized so far arises from interannual variations in the jet, largely associated with its latitude rather than speed. There likely remains further potential for predictability on longer, decadal timescales. In the small sample of models analyzed here, improved representation of the structure of jet variability does not translate to enhanced seasonal forecast skill.
AB - The winter North Atlantic Oscillation (NAO) has varied on interannual and decadal timescales over the last century, associated with variations in the speed and latitude of the eddy-driven jet stream. This paper uses hindcasts from two operational seasonal forecast systems (the European Centre for Medium-range Weather Forecasts's seasonal forecast system, and the U.K. Met Office global seasonal forecast system) and a century-long atmosphere-only experiment (using the European Centre for Medium-range Weather Forecasts's Integrated Forecasting System model) to relate seasonal prediction skill in the NAO to these aspects of jet variability. This shows that the NAO skill realized so far arises from interannual variations in the jet, largely associated with its latitude rather than speed. There likely remains further potential for predictability on longer, decadal timescales. In the small sample of models analyzed here, improved representation of the structure of jet variability does not translate to enhanced seasonal forecast skill.
KW - ECMWF IFS
KW - jet stream
KW - North Atlantic Oscillation
KW - seasonal forecasting
UR - http://www.scopus.com/inward/record.url?scp=85071607875&partnerID=8YFLogxK
U2 - 10.1029/2019GL084402
DO - 10.1029/2019GL084402
M3 - Article
AN - SCOPUS:85071607875
SN - 0094-8276
VL - 46
SP - 10159
EP - 10167
JO - Geophysical Research Letters
JF - Geophysical Research Letters
IS - 16
ER -