Notable Contributions of Aerosols to the Predictability of Hail Precipitation

Abstract

AbstractThere are increasing concerns about the uncertainty aerosols produced in forecasting precipitation, particularly hail. This study provides an assessment of the contribution of aerosols to hail predictability by varying both the cloud condensation nuclei concentration (CCNC) and the initial meteorological conditions based on ensemble runs of 1,200 cloud‐resolving simulations. Although the meteorological perturbations produce large uncertainties in both hail and total precipitation, varying CCNC by an order of magnitude causes even larger uncertainties than the meteorological perturbations. Changing CCNC modifies the predictability of hail precipitation, with higher predictability in moderately polluted environments compared with very clean and polluted environments. Perturbing the initial meteorological conditions does not qualitatively change how aerosols affect hail and total precipitation. Constraining the initial meteorological perturbations helps reduce CCNC‐caused uncertainty. These findings suggest the importance of considering aerosol effects in severe weather simulations and forecasting.