A forensic re-analysis of one of the deadliest European tornadoes

Abstract

Abstract.Extremely rare events with high potential impact, such as violent tornadoes, are of strong interest for climatology and risk assessment. In order to obtain more knowledge about the most extreme events, it is vital to study historical cases. The purpose of this paper is twofold: (1) to demonstrate how a windstorm catastrophe that happened 100 years ago, such as the Wiener Neustadt, Lower Austria, tornado on 10 July 1916, can be successfully re-analyzed using a forensic approach, and (2) to propose a repeatable working method for assessing damage and reconstructing the path and magnitude of local windstorm and tornado cases with sufficient historical sources. Based on the results of the forensic reanalyses, a chronology of the tornado impact is presented, followed by a description of the key tornado characteristics: a maximum intensity rating of F4, a damage path length of 20 km and a maximum visible tornado diameter of 1 km. Compared to a historical scientific study published soon after the event, additional new findings are presented, namely the existence of two predecessor tornadoes and a higher number of fatalities: at least 34 instead of 32. While the stormscale meteorology could not be reconstructed, rich damage data sources for the urban area of Wiener Neustadt facilitated a detailed analysis of damage tracks and wind intensities within the tornado. The authors postulate the requirement for an International Fujita Scale to rate tornadoes globally in a consistent way, based on comparable damage indicators.

Tornadoes in Romania—from Forecasting and Warning to Understanding Public’s Response and Expectations

“…Such discussions used to be opened only after major events [20,23]. To the best of our knowledge, only the U.S. and Canada have implemented a dedicated tornado warning system [75][76][77], while in Europe the problem is still under debate [19,20,25]. As tornado forecasting is one of the most demanding tasks of any meteorological service, the low frequency of such phenomena may add supplementary pressure for inexperienced forecasters.…”

A methodology to conduct wind damage field surveys for high-impact weather events of convective origin

“…One of them is planning the route of the fieldwork. As mentioned in Holzer et al (2018) it is strongly recommended to start in situ damage surveys as soon as possible, especially if urban areas have been affected. Emergency and clearing services may start repair only a few hours after the event, which can alter the quality and quantity of possible information available during the fieldwork.…”

“…They pointed out the necessity of geo-referencing the locations where photos were taken and the damaged elements, using GIS tools and triangulation methods. Furthermore, Holzer et al (2018) provided useful indications for current field studies, such as visiting affected areas as soon as possible and also providing an estimation of the wind intensity for each damaged element given by the pair damage indicator-degree of damage (DI-DoD) from the EF scale (WSEC, 2006), similarly to other authors such as Burgess et al (2014).…”

“…The methodology presented here is based on previous studies (McDonald and Marshall, 1984;Bunting and Smith, 1993;Gayà, 2018;Holzer et al, 2018) and also on 136 wind damage surveys performed between 2004 and 2018 by the authors. All the analysed events have been recorded in Spain (south-western Europe), which includes the vast ma-Figure 1.…”

“…On the other hand, the analysis of historical events such as those of Gayà (2007) and Holzer et al (2018) showed the utility of press references and in situ images taken by witnesses on reconstructing tornado damage paths. They pointed out the necessity of geo-referencing the locations where photos were taken and the damaged elements, using GIS tools and triangulation methods.…”