Snowfall in the Gangwon region of the Korean peninsula generally occurs due to the complex terrain of the Taebaek mountain range and it results in severe economic losses. When the siberian High expands to Manchuria and Primorsky Krai region, easterly winds which advect cold air to the East Sea of the Korean peninsula prevail. Here, the cold air and Warm sea result in large air-sea temperature difference and it promotes the development of snow clouds. The snow clouds move to the Yeongdong (YD) region by the easterly winds and even more penetrate inland frequently. This snowfall mechanism accounts for most of the winter precipitation over the YD region, and thus needed to be investigated. In the present study, we focused on the snowfall over not only the coastal area, but also the inland region. We used the ERA-Interim data provided by the European Center for Medium-range Weather Forecasts (ECMWF), wind observation data and the Local Data Assimilation and Prediction System (LDAPS) data provided by Korea Meteorological Administration (KMA) for analysis of the snowfall over the Daegwallyeong (DGY) region according to the synoptic patterns and vertical structures. In terms of synoptic patterns, the results show that the snowfall occurs over the DGY region as well as the YD region when the Siverian High expands to Manchuria and Primorsky Krai region. Here, migratory low passing over the southern region of Korean Peninsula intensifies easterly winds and supplies more moisture to the YD region, which induces heavy snowfall. In the vertical structure of the atmosphere, it was judged that the layer where the wind direction changed and Froude number at the meeting point with the mountain range were the main determinant of the position of the snowfall. The Global/Regional Integrated Model system-Regional Model Program (GRIMs-RMP) was used to perform an ideal experiment on two factors and analyze the effect.