Abstract: This study presents an in-depth analysis of a snowstorm influenced by the warm conveyor belt (WCB) on December 14, 2023, using ground-based observations from cloud radar, disdrometers, and wind profiler radar, along with simulations from the Weather Research and Forecasting mesoscale numerical model. Our results showed that the snowstorm was primarily influenced by the southwest WCB and the northeast cold air return flow. Two distinct snow events (accumulated snowfall of 8 mm) were observed at the Huozhou site in southern North China. The snowfall cloud was primarily composed of solid-phase particles and exhibited a well-defined layered structure. During the early stages of the snowfall, almost no upward motion was observed within the clouds. In the WCB region (2–3 km), water vapor primarily condensed into supercooled cloud water (maximum 0.4 g kg⁻¹), whereas the upper levels were dominated by ice and snow deposition processes. As latent heat was continuously released through condensation, a significant upward motion developed within the clouds, facilitating vertical mixing of ice and snow particles. These particles underwent deposition and aggregation, with larger particles descending into the WCB region. Through accretion and Bergeron processes, liquid water was rapidly consumed, leading to the formation of numerous graupel particles with a peak diameter of 1.4 mm, which eventually fell to the ground. As the snowfall cloud continued to develop, the water vapor transport by the WCB weakened. In the mid-to-lower troposphere (2–6 km), the ambient water vapor pressure lies between the saturation vapor pressures over ice and water. The maximum water vapor depletion rate exceeds 4.5×10⁻⁴ g kg⁻¹ s⁻¹. Under supersaturation with respect to ice, ice and snow particles grow continuously through deposition. During their descent, they collide and aggregate with graupel particles in the lower layers, eventually falling to the surface together. At this stage, surface precipitation primarily consisted of a mixture of small snowflakes and snow graupel, with peak particle diameters ranging from 0.6 to 0.8 mm. Despite weakening water vapor transport, the substantial latent heat released during deposition continued to promote upward motion and cloud development, sustaining surface snowfall. These results highlight that the remarkable upward motion triggered by latent heat release during water vapor deposition was a key factor in the observed heavy surface snowfall.