Based on observational datasets and reanalysis data, this study investigated four severe low-temperature freezing rain and snow events that significantly impacted Hunan Province. Synergistic anomalies in atmospheric circulation systems associated with these cryogenic disasters were diagnostically analyzed, and the influences of circulation patterns and atmospheric stratification on precipitation phase transitions and multimodal precipitation characteristics in Hunan were systematically examined. Critical factors and predictive indicators for freezing rain and snow forecasting were subsequently identified. Results demonstrate five essential forecasting elements: blocking high-pressure systems, upper-and lower-level jet streams, southern branch troughs, surface cold highs, and temperature profiles. Key findings reveal that the intensified polar vortex splitting provides favorable conditions for blocking pattern development. The established blocking regime enhances meridional circulation disturbances, facilitating persistent cold air incursions southward. Concurrently, the robust western Pacific subtropical high acts as a barrier to further cold air penetration, crucially influencing freezing rain formation in southern Hunan. The spatial positioning and intensity of blocking highs critically determine cryogenic event evolution, with optimal cold air transport occurring when blocking highs reside between 60°E and 120°E. Southern branch troughs serve as principal conduits for moisture and energy supply during these events. Hunan's unique topography establishes characteristic vertical temperature stratifications that directly govern precipitation phase transitions and sustain concurrent precipitation types. These findings collectively enhance the physical understanding and predictive capability for complex winter precipitation systems in central China.