Evaluation and Analysis of a Gale Process Affecting Shandong Caused by a Strong Cold Wave in Early 2023

A regional extreme cold wave gale process occurred in Shandong and its coastal areas from January 13th to 15th, 2023. In the forecast of this process, there existed an obvious weaker bias between the forecast and the actual. In order to summarize the forecast deviation of this process and accumulate experience for future forecasts, based on conventional observation and numerical forecast data in the same period, the multimodel forecast performance is comprehensively evaluated, using threat score (TS), mean error (ME), mean absolute error (MAE), and root mean square error (RMSE). By comparing the weather situation and forecasting information of this process with those of a previous gale case, the main reasons for the weak bias between the forecast and actual have been identified. Additionally, two conceptual models for extreme cold wave winds along the Shandong Coast are also proposed. In the later forecasting businesses, we should pay attention to not only the intensity and pressure gradient of cold air but also the path of cold air and the situation of the underlying surface, which will play a key role in the generation of gales. When cold air that affects eastern China with the same intensity moves southward through the northerly path, it is more likely to cause extreme windy weather than those that take the other paths.