An F3 downburst in Austria—A case study with special focus on the importance of real-time site surveys

On 1 March 2008, the powerful late winter cyclone “Emma” caused widespread damage over Central Europe. Deep convection along the cold front resulted in a significant enhancement of gusts in some places, peaking in an unusually strong downburst in a sparsely populated area near Braunau (Austria). Only a site survey revealed the extraordinary intensity of this downburst that vividly contrasted with its sparse media coverage.This study aims to describe the development of this severe local storm by using remote sensing data and objective analysis fields, as well as its damage analysis by presenting photographs and maps created during the site survey. A top-down approach from synoptic scales towards small scales is pursued in order to accentuate the increasing uncertainties with decreasing scales. Finally the subtle but far-reaching aftermath of this storm is presented, which is not only confined to the meteorological community but also reacts on risk management circles, authorities and the general public. Special emphasis of the whole study is placed on the fact that the assessment of this case would have taken a significantly different outcome without the accomplishment of this site survey.

Research highlights
► On 1 March 2008, the strongest downburst in Austria's recorded history occurred.
► It was embedded in a synoptic-scale storm field of a strong wintertime cyclone.
► As this event happened in a sparsely populated area, it escaped the media‘s notice.
► Thus, only a site survey revealed the extraordinary intensity of this local storm.
► This study presents storm synthesis and storm analysis in a top-down approach.