This study investigated the meteorological characteristics and mechanisms of three distinct heavy snowfall events that occurred over the central Korean Peninsula on November 27, 2024, December 15, 2024, and March 18, 2025. Satellite imagery, total precipitable water, integrated vapor transport, and wind and pressure field data revealed that the November 27, 2024 event represented a compound case wherein strong moisture transport from the southwestern sea combined with a cut-off low, leading to the development of an atmospheric river (AR), synoptic-scale ascent, and countrywide heavy snowfall. In contrast, the December 15 2024 event exhibited a typical lake-effect snowfall pattern characterized by weak AR activity and a dominant localized moisture supply from the Yellow Sea, resulting in short-lived and spatially confined snowfall. The March 18, 2025 event was a mixed cycloniclake-effect case triggered by the interaction between mid-latitude moisture transported by southwesterly winds and an upper-level low, producing significant snowfall over the Seoul metropolitan and Yeongdong regions. These differences arise from variations in AR strength, lakeeffect processes, and cyclonic development, whereas all three events shared enhanced thermal instability, a moisture supply associated with a large SST850 hPa temperature difference (ΔT>10oC), and a prevailing northwesterly flow. These specific cases show that heavy snowfall intensity and duration are closely linked to sequential interactions between large-scale AR processes, regional lake effects, and cyclonic mechanisms. Overall, this study suggests that an increased AR frequency under climate change scenarios may increase the risk of extreme snowfall, thereby contributing to improved weather forecasting and disaster preparedness strategies.

Abstract
I. Introduction
II. Data and Analysis Methods
    1. Data and Study Domain
    2. Study Area and Period
    3. Detection and Classification Methods forAtmospheric Rivers Associated with MoistureTransport
    4. Analytical Methods for Lake-Effect Snowfalland Cyclonic Snowfall
III. Results and discussions
    1. Analysis of Heavy Snowfall Events in Autumn,Winter, and Spring
    2. Role of Atmospheric River-Induced MoistureTransport over the Yellow Sea in SustainingHeavy Snowfall
    3. Formation Processes of Lake-Effect andCyclonic (Cut-Off Low or Double-Low) SnowfallBands
IV. Discussion
V. Conclusion
References

• Seong Un Kim(Chungbuk Carbon Neutrality Center, Korea National University of Education, Cheongju 28173, Korea, Department of Elementary Education, Korea National University of Education, Cheongju 28173, Korea)
• Okjin Jung(Chungbuk Carbon Neutrality Center, Korea National University of Education, Cheongju 28173, Korea, Department of Environment Education, Korea National University of Education, Cheongju 28173, Korea)
• Cheol Jae Lee(Department of Environment Education, Korea National University of Education, Cheongju 28173, Korea)
• Yun Seob Moon(Department of Environment Education, Korea National University of Education, Cheongju 28173, Korea) Corresponding author