Hail events seldom occur in autumn in Hunan Province, but on November 9, 2023, Changsha experienced an unusual heavy hail event in late autumn. To investigate the causes and evolution stages of the hail event, by integrating multi-source observational data, reanalysis data sets, and dual-polarization radar observations from Changsha, this paper analyzes the characteristics of the ambient precursors and the radar echo characteristics of the convection evolution, and also discusses the significance of the storm parameter evolution on the early warning indication of the process. The findings include: 1) The heavy hail developed under a synoptic configuration characterized by an eastward-migrating upper-level trough and a low-level vortex. Conditional instability allowed the low-level convergence line to lift air parcels above the level of free convection, triggering intense convection. At the same time, optimal hail growth was facilitated by favorable vertical positioning of the -20℃ isotherm and the wet-bulb 0℃ layer. 2) The thermal conditions were moderate, with the K-index and 850-500 hPa temperature lapse rate below empirical thresholds for spring hail storms. In contrast, moisture and dynamic conditions were favorable, the development and maintenance of updraft associated with the differential reflectivity factor (ZDR) column were among the driving factors in the large hail process. 3) The updraft area corresponded to the ZDR column, while the downdraft aligned with the ZDR low-value band and the "specific differential phase (KDP) foot", which extended near the ground. Dual-polarization parameters such as KDP and correlation coefficient (CC) are useful for determining the phase state and size of hail. 4) During the development stage, the maximum reflectivity factor (DBZM) increased, the height of DBZM (HT) reached the effective growth layer for hail stones, the echo top height (TOP) rose, and the vertically integrated liquid content (VIL) increased abruptly. Among these, HT has indicator significance 2-3 individual sweeps earlier than DBZM and VIL. The research findings could provide a reference for short-time and nowcasting of autumn hail events in Hunan Province.