The role of large-scale atmospheric flow and Rossby wave breaking in the evolution of extreme windstorms over Europe
Article first published online: 8 NOV 2012
©2012. American Geophysical Union. All Rights Reserved.
Geophysical Research Letters
Volume 39, Issue 21, November 2012
How to Cite
2012), The role of large-scale atmospheric flow and Rossby wave breaking in the evolution of extreme windstorms over Europe, Geophys. Res. Lett., 39, L21708, doi:10.1029/2012GL053408., and (
- Issue published online: 8 NOV 2012
- Article first published online: 8 NOV 2012
- Manuscript Revised: 5 OCT 2012
- Manuscript Accepted: 5 OCT 2012
- Manuscript Received: 7 AUG 2012
- North Atlantic Oscillation;
- extreme European windstorms;
- large-scale dynamics
 We investigate the relationship between large-scale atmospheric flow and the evolution of the most extreme windstorms affecting Western Continental Europe. The 25 most destructive Western Continental European wind storms are selected from a 43-year climatology. 22 of these storms are grouped as having a similar trajectory and evolution. We show that these storms typically occur during particularly strong and persistent positive NAO anomalies which peak approximately 2 days before the storms' peak intensity; the NAO pattern then shifts eastward to a position over the European continent when the storms strike Europe. A temporal composite of potential temperature on the 2-PVU surface suggests that this NAO shift is the result of simultaneous cyclonic and anticyclonic wave breaking penetrating further to the east than during a typical high-NAO event. This creates an extremely intense, zonally-orientated jet over the North Atlantic whose baroclinicity favours explosive intensification of storms while steering them into Western Continental Europe.