Abstract: Using daily meteorological station data from Hubei province,NCEP reanalysis data,and climate indices,this study analyzes the anomalous climate characteristics and their causes during the Meiyu season (May 31-July 8) and midsummer (July 9-August 31) in Hubei province in 2022.The results show that the onset of the Meiyu season was abnormally early with an extended duration in Hubei province in 2022.However,precipitation was unevenly distributed with unstable intensity and overall deficit in rainfall.After the Meiyu season,temperature was abnormally high,with heatwaves that were exceptionally persistent and intense,breaking historical records in the province's meteorological observation history.The early northward shift of the East Asian subtropical westerly jet and the Western Pacific subtropical high (WPSH),combined with adjustments in mid-latitude and high-latitude circulation systems,were the primary reasons for the significantly early onset of the Meiyu season despite poor moisture conditions in Hubei province.Under the combined influence of multiple external forcing signals,including the continuing development of a double-peak La Niña event and warm sea surface temperature anomalies in the Indian Ocean and equatorial Atlantic,jointly contributed to enhanced subsidence in the East Asian subtropical region via the Hadley circulation,resulting in significantly stronger high pressure in this area.During midsummer,the westward extension and intensification of the WPSH along with the abnormal eastward expansion of the South Asian high,caused Hubei province to remain under the prolonged influence of deep warm high-pressure system,leading to persistent,extreme,hot,and high-temperature weather.

Key words: East Asian subtropical westerly jet, Western Pacific subtropical high, La Niña event, Extreme high temperature