2026年春季中国主要天气气候事件特征OA

In the spring of 2026,China experienced a pronounced warm and humid climatic regime.The national mean temperature was 1.1℃higher than normal,ranking as the fourth highest for the same period since 1961.Daily maximum temperatures at 61 meteorological stations reached or exceeded their historical spring maxima.The mean precipitation amount was 15.8%above normal,ranking as the fifth highest for the same period since 1961 and the highest record over the past decade.The intraseasonal evolution of precipitation exhibited marked phase transitions.Positive rainfall anomalies prevailed during March and April,followed by a notable shift from deficits to surpluses in May.A total of ten regional heavy-rainfall events affected China,close to the normal,and all of them occurred over southern China.The heavy-rainfall event during 13-21 May was the strongest regional rainstorm event of the year and also the strongest May rainstorm event on record.This event was characterized by exceptional duration,extensive spatial coverage,and extraordinary extremity,with both its maximum affected area and total duration ranking first among all May events since 1961.The first high-temperature event occurred in China from 25 to 29 May,more than 20 days earlier than climatology,and meteorological drought developed intermittently in several regions.Cold air activity was less frequent than normal and generally weaker,although a late-season cold wave in May affected northern China.Severe convective weather occurred later than usual but was frequently during spring.The extreme heavy precipitation in mid-to-late May exhibited characteristic of strong intensity both locally and over a large area,with daily precipitation amounts exceeding historical records at multiple locations.The frequency of dust weather process was less than that of the same period in normal years,with the sandstorm event during 17-20 April exhibited strong intensity and a wide affected area.Preliminary analysis suggests that El Niño conditions emerged in May,as sea surface temperature anomalies in the Niño 3.4 region of the equatorial central-eastern Pacific continued to rise.Meanwhile,the western Pacific subtropical high shifted northward earlier than climatology,with both its area and intensity indices reaching their highest values for the corresponding period since 1979.In addition,northern China was located along the northern periphery of the western Pacific subtropical high,where anomalously strong upward motion contributed to increased precipitation.The concurrent northern and southern rainbelts from mid-May onward,further amplifying the extremity of precipitation and severe convective events.