John T. Allen

TL;DR: In this article, the authors show that the large-scale climate system and hazardous convective weather (HCW; tornadoes, hail, and damaging wind), particularly over the USA where there are large societal impacts and a long observational record.

TL;DR: In this paper, large-scale environmental indices show that the El Nino/Southern Oscillation modulates global weather and climate and also affects the frequency of tornado and hail events in the central United States.

TL;DR: In this paper, a proximity climatology of environments was developed for observed severe thunderstorms in Australia during the period 2003-2010 using the ERA-Interim reanalysis, with particular focus on the influence of El Nino-Southern Oscillation (ENSO) on the occurrence of severe thunderstorm environments.

TL;DR: In this article, the authors explored the main features and limitations of the United States hail observation dataset, including the implications of an increasing frequency in the time series, approaches to spatial smoothing of observations, and the sources that contribute to the hail dataset.

TL;DR: An empirical model relating monthly hail occurrence to the large-scale environment has been developed and tested for the United States (U.S.). Monthly hail occurrence for each 1°×1° grid box is defined as the number of hail events that occur there during a month; a hail event consists of a 3 h period with at least one report of hail larger than 1 in this paper.