Links between hail hazard and climate modes of variability across Australia

Abstract Hailstorms are destructive and dangerous phenomena that can cause large losses, motivating better understanding of their occurrence. As climate modes of variability influence temperature and moisture and hence convective instability, they offer predictive skill for hail conditions. Here, we examine relationships between hail‐prone days across Australia and the El Niño–Southern Oscillation (ENSO), Indian Ocean Dipole (IOD), and Southern Annular Mode (SAM). Hail‐prone days were identified using a hail proxy applied to European Centre for Medium‐Range Weather Forecasts Reanalysis v5 (ERA5) data from 1979 to 2022. Hail‐prone day anomalies were correlated with strength‐of‐mode indices. Broad areas of the country's interior show increased hail‐prone days during La Niña, negative IOD, and positive SAM in spring. The relationship with IOD and SAM is significant in winter for Brisbane and to some extent for Sydney, reversing sign in summer. Anomalies increase over Western Australia's south during El Niño and positive IOD in spring. Our work highlights potential connections between climate modes and hail‐prone conditions, investigates meteorological factors behind the observed correlations, and helps us understand annual variability to improve seasonal prediction.