Abstract:
Using live precipitation data of Chengdu, ERA5 reanalysis data, and typhoon track data from 1980 to 2020, the regional heavy rain events in Chengdu that were influenced by typhoons were statistically analyzed. The results indicate that: (1) There are two direct influence conceptual models (southerly jet and typhoon inverted trough) and three indirect influence models (oscillation of the Western Pacific Subtropical High, enhancement of the low-level wind field, and blocking of the eastward movement of plateau low-pressure systems) for heavy rain. (2) In these models, the probability of precipitation occurring in western Chengdu is relatively high, followed by the central area, while the probability is lower in the eastern area. When precipitation occurs in western Chengdu, the associated typhoon tracks are mostly westward or northwestward. (3) Both the K-index and the difference in pseudo-equivalent potential temperature between 500 hPa and 850 hPa show certain indicative value for forecasting regional heavy rain events in Chengdu influenced by typhoons.