Severe storm research with thundeR package - improvements in calculation procedures of convective parameters

ThundeR rawinsonde processing package has been under development since 2017. It is a freeware R language package for sounding and hodograph visualization, and rapid computation of convective parameters commonly used in the research and operational prediction of severe convective storms. Ability of the package to calculate more than 300 parameters in ~1 centisecond enables rapid processing of large numerical datasets. Over the recent years thundeR has been applied on global reanalysis datasets, operational numerical weather prediction models, and used to study environments associated with global lightning observations and severe weather reports from Europe, North America, South America and Australia. ThundeR also contributed to development of ESSL’s AR-CHaMo models and was applied by severe storm scientists in several countries, including national hydrometeorological institutes. Construction of environmental datasets collocated with severe storms observations from different parts of the world served as a platform to evaluate the skill of hundreds of convective parameters in predicting specific convective hazards, and allowed to test new parameter ideas through an iterative development process. In this work we will discuss modifications in calculation procedure of existing parameters, which led to more skillful identification of environments supportive of lightning, large hail, tornadoes and severe wind of both severe and significant severe intensity. Examples concern modifications in the calculation procedure of convective inhibition, lifted index or storm-relative helicity, and introduce new ventilation parameter along with two new parcel lifting types: most-unstable-mean-layer (MUML) and most-unstable-above-500m (MU5). Authors will also present examples of how obtained results can be applied in the operational prediction of severe convective storms and modeling their climatology on the global scale.