Australian Tornadoes in 2013: Implications for Climatology and Forecasting

Abstract

During 2013, multiple tornadoes occurred across Australia, leading to 147 injuries and considerable damage. This prompted speculation as to the frequency of these events in Australia, and whether 2013 constituted a record year. Leveraging media reports, public accounts and the Bureau of Meteorology observational record, sixty-nine tornadoes were identified for the year in comparison to the official count of thirty-seven events. This identified set and the existing historical record were used to establish that, in terms of spatial distribution, 2013 was not abnormal relative to the existing climatology, but numerically exceeded any year in the Bureau record. Evaluation of the environments in which these tornadoes formed illustrated that these conditions included tornado environments found elsewhere globally, but generally had a stronger dependence on shear magnitude than direction, and lower lifted condensation levels. Relative to local environment climatology, 2013 was also not anomalous. These results illustrate a range of tornadoes associated with cool season, tropical cyclone, East Coast low, supercell tornado and low shear/storm merger environments. Using this baseline, the spatial climatology from 1980-2019 as derived from the non-conditional frequency of favorable significant tornado parameter environments for the year is used to highlight that observations are likely an underestimation. Applying the results, discussion is made of the need to expand observing practices, climatology, forecasting guidelines for operational prediction, and improve the warning system. This highlights a need to ensure that the general public is appropriately informed of the tornado hazard in Australia, and provide them with the understanding to respond accordingly.

Climatology of 500‐hPa geopotential height anomalies associated with May tornado outbreaks in the United States

“…Scientists have studied tornadic storm systems because of their impacts on life and property (Doswell and Burgess, 1993; Silva Dias, 2011; Groenemeijer and Kühne, 2014; Taszarek and Brooks, 2015; Bikos et al ., 2016; Xue et al ., 2016; Antonescu et al ., 2017; Allen et al ., 2021). Tornado outbreaks (TOs), in particular, threaten society because they often comprise multiple, violent, long‐track tornadoes and affect populated areas (Brooks, 2004; Ćwik et al ., 2021).…”