The role of large-scale atmospheric flow and Rossby wave breaking in the evolution of extreme windstorms over Europe
2012 (English)In: Geophysical Research Letters, ISSN 0094-8276, Vol. 39, L21708- p.Article in journal (Refereed) Published
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.
Place, publisher, year, edition, pages
2012. Vol. 39, L21708- p.
Research subject Atmospheric Sciences and Oceanography
IdentifiersURN: urn:nbn:se:su:diva-83809DOI: 10.1029/2012GL053408ISI: 000310963000001OAI: oai:DiVA.org:su-83809DiVA: diva2:577133