Jiangsu province has entered a “reverse Meiyu” (dao huangmei) weather pattern, forcing a return to humid, rainy conditions shortly after the official end of the traditional rainy season. According to meteorological data, the region is experiencing frequent convective weather, including localized downpours and strong winds, as cold and warm air masses clash over the area.
Understanding the “Reverse Meiyu” Phenomenon
While the region typically shifts into a stable, hot summer after the Meiyu season, this year has seen an abnormal atmospheric reversal. Meteorological experts explain that the subtropical high-pressure system has failed to remain stable, undergoing a phase of southward retreat. This movement allows warm, moist air to flow back into the Yangtze River Delta, where it meets infiltrating cold air from the north. This interaction creates the “Meiyu rollback,” characterized by more intense, sudden convective storms than those seen during the standard rainy season.
Did You Know? The “reverse Meiyu” is a specific meteorological anomaly for the Yangtze River Delta, occurring when the subtropical high-pressure system becomes unstable and retreats, allowing cold and warm air to collide again after the traditional rainy season has officially concluded.
Recent Storm Activity and Regional Impact
The intensity of this weather pattern was evident between 11:00 and 14:00 on July 20. Monitoring data shows that 76 stations across Yancheng, Taizhou, and Nantong recorded rainfall exceeding 25 millimeters. Six stations in Yancheng and Taizhou reached the “heavy rain” threshold by recording over 50 millimeters of precipitation. The highest rainfall was recorded at Xinswa Village in Yancheng’s Tinghu District, reaching 55.3 millimeters.
Taizhou’s Xinghua area experienced the most concentrated rainfall, with Shenlun Town recording a peak hourly intensity of 52.0 millimeters. Alongside the heavy precipitation, high winds have impacted the region; a station in Dongtai, Yancheng, recorded a maximum wind speed of 17.3 meters per second, meeting the criteria for an 8-level gale.
Weekly Weather Outlook and Temperature Shifts
The province is expected to follow a “rain first, heat later” trajectory throughout the week. Through July 23, temperatures will remain between 30℃ and 33℃, with high humidity keeping conditions feeling muggy. Starting July 24, the rain belt is forecast to shift northward as the subtropical high-pressure system regains control over the areas south of the Huaihe River.
From July 25 to 26, most areas south of the Huaihe River will enter a period of clear, hot summer weather with temperatures likely to reach 35℃ to 36℃. Air quality is expected to remain generally favorable through July 24, though it may decline to “light pollution” levels by July 25 as atmospheric diffusion conditions worsen, with ozone identified as the primary pollutant.
Frequently Asked Questions
What is the primary cause of the current weather in Jiangsu?
The weather is caused by an unstable subtropical high-pressure system that retreated southward, allowing warm, moist air to return and collide with cold air from the north.
How intense was the rainfall on July 20?
Between 11:00 and 14:00, 76 stations across four cities recorded over 25 millimeters of rain, with the highest single-station total reaching 55.3 millimeters in Yancheng.
When will the region transition to hot, sunny weather?
Meteorological forecasts indicate a transition starting July 24, with areas south of the Huaihe River expected to experience temperatures between 35℃ and 36℃ by July 25 and 26.
Are you prepared for the rapid transition from heavy rain to high summer heat in your area?
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