Abstract: The 24th Winter Olympic Games in 2022 (referred to as the Beijing Winter Olympic Games) presented a strict requirement for “100-meter and minute-level updated” meteorological support services, especially for refined and accurate forecasts of wind, gusts, temperature, rain, snow, etc. To meet this demand, the Institute of Urban Meteorology developed the Rapid-refresh Integrated Seamless Ensemble (RISE) system, which provides fast fusion forecasts based on multi-source data with a 100-meter resolution scale and minute-level update frequency. This system was implemented for meteorological support during the Beijing Winter Olympic Games. This paper first summarizes the basic framework, core algorithms, and technical advancements of the RISE system. The system integrates multi-source observation data and model forecast products, including data from 5-min updated surface automatic weather stations, 6-min updated weather radars, nowcasting products, mesoscale numerical forecast products, and high-resolution real-time large eddy simulations. The paper also introduces complex terrain downscaling, seamless fusion, and high-resolution deviation correction technologies. The system generates 10-min updated fine-grid analysis and 0–24-h forecast products, including surface temperature, humidity, wind, gusts, precipitation, and precipitation types, with a horizontal resolution of 500 meters in the Beijing–Tianjin–Hebei region and 100 meters in mountainous areas where Olympic events were held. Additionally, it provides 12-hour updated 0–10-d forecasts of conventional meteorological elements with a 67-meter resolution for six outdoor Winter Olympic venues. Based on long-term verification and several typical cases, this paper also evaluates the real-time application performance of RISE products during the Winter Olympic test and race periods, providing an assessment of the current capabilities of winter weather predictions in complex mountainous areas of Beijing and surrounding regions. Finally, the paper discusses the future development and key technical challenges of 100-meter and minute-updated weather forecasting technology. The results of this study can provide precise and accurate meteorological forecast support for major events such as the Winter Olympics. The findings can also be applied to daily weather forecasting, early warning services, and other interdisciplinary fields, such as energy and hydrology, demonstrating significant scientific and practical value.