Stratospheric influence on the winter North Atlantic storm track in subseasonal reforecasts ...

• Main Authors: Afargan-Gerstman, Hilla, Büeler, Dominik, Wulff, Ole, Sprenger, Michael, Domeisen, Daniela
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2024
• Subjects: Arctic; North Atlantic; North Atlantic oscillation
• Online Access: https://dx.doi.org/10.3929/ethz-b-000662813; http://hdl.handle.net/20.500.11850/662813

Extreme stratospheric polar vortex events, such as sudden stratospheric warmings (SSWs) or extremely strong polar vortex events, can have a significant impact on surface weather in winter. SSWs are most often associated with negative North Atlantic Oscillation (NAO) conditions, cold air outbreaks in the Arctic and a southward-shifted midlatitude storm track in the North Atlantic, while strong polar vortex events tend to be followed by a positive phase of the NAO, relatively warm conditions in the extratropics and a poleward-shifted storm track. Such changes in the storm track position and associated extratropical cyclone frequency over the North Atlantic and Europe can increase the risk of extreme windstorm, flooding or heavy snowfall over populated regions. Skillful predictions of the downward impact of stratospheric polar vortex extremes can therefore improve the predictability of extratropical winter storms on subseasonal timescales. However, there exists a strong inter-event variability in these downward ... : Weather and Climate Dynamics, 5 (1) ...