Sounding-derived parameters and their ability to forecast individual severe weather threats for the region of central Europe.
|Year of publication||2013|
|MU Faculty or unit|
|Description||Study is devoted to the analysis of more than 35 environmental parameters (indices) and their ability to discriminate between the intensity categories of individual severe weather types (hail, wind gusts, excessive precipitation). Intensity categories were delineated as non-severe, severe and extremely severe while severity for each of the events was assigned using the ESWD data. Environmental parameters (indices) have been processed from 1962 proximity soundings acquired for 4 years of thunderstorm activity (2008-2011) in the region of central Europe. Ability of parameters to discriminate between the intensity categories has been determined via non-parametric statistical tests (using p-values and test score values). One of the primary findings is that the discriminatory ability of a certain parameter is often very different for individual severe weather types, another being that even parameters with the best scores exhibit at least some overlap between the values of individual intensity categories. Statistical results showed that the best discriminatory skills were found for the hail events, worst for the excessive precipitation. Moreover, we found that it is easier to discriminate non-severe and severe events than severe and extremely severe ones. Severe hail environments were well predicted using the buoyancy-related parameters, while severe wind gust environments were more sensitive to the vertical wind shear. Simple combinations of buoyancy and wind shear proved as the best predictors for both severe weather types. In case of the excessive precipitation, results were different with a tendency for severe events to occur in the environments favoring high precipitation rates / efficiency. Also, tornado environments were examined with the finding that even in the favorable range of parameters, non-tornadic cases dominate. Generally speaking, primary goal is an assessment of the severe weather predictability using simple, sounding derived parameters and the outline of main limitations that stem from using them, especially regarding the parameter “threshold” values.|