Simulating Hail and Lightning over the Alpine Adriatic Region - A model
Intercomparison Study
Abstract
Hail is a significant convective weather hazard, often causing
considerable crop and property damage across the world. Although
extremely damaging, hail still remains a challenging phenomenon to model
and forecast, given the limited computational resolution and the gaps in
understanding the processes involved in hail formation. Here, eight
hailstorms occurring over the Alpine-Adriatic region are analyzed using
Weather Research and Forecasting (WRF) and Consortium for Small Scale
Modeling (COSMO) simulations, with embedded HAILCAST and Lightning
Potential Index (LPI) diagnostics at kilometer-scale grid spacing
(~2.2 km). In addition, a model intercomparison study is
performed to investigate the ability of the different modeling systems
in reproducing such convective extremes, and to further assess the
uncertainties associated with simulations of such localized phenomena.
The results are verified by hailpad observations over Croatia, radar
estimates of hail over Switzerland and lightning measurements from the
LINET network. The analysis revealed that both HAILCAST and LPI are able
to reproduce the areas and intensities affected by hail and lightning.
Moreover, the hail and lightning fields produced by both models are
similar, although a slight tendency of WRF to produce smaller hail
swaths with larger hailstones and higher LPI compared to COSMO is
visible. It is found that these differences can be explained by
systematic differences in vertical profiles of microphysical properties
and updraft strength between the models. Overall, the promising results
indicate that both HAILCAST and LPI could be valuable tools for
real-time forecasting and climatological assessment of hail and
lightning in current and changing climates.