In late July, Beijing, Tianjin, and Hebei Province were hit by extreme rain and flooding following Typhoon Doksuri. This weather event, the most severe in over a decade, caused widespread damage and displacement of hundreds of thousands of residents in an area as large as Britain.
The Severity of Rainfall:
The amount of rainfall during this period broke many local meteorological records. In Beijing’s Changping district, they recorded the highest precipitation in over 140 years, surpassing the 1891 record. It measured 744.8mm (29.3 inches) between Saturday and Wednesday. Hebei also experienced intense rain, with one weather station recording 1,003mm of rain over three days – an amount usually seen in half a year.
How the Extreme Rain Occurred:
The heavy rains were a result of a combination of factors. The remnants of Typhoon Doksuri, along with warm and humid air-flows and water vapour brought by Typhoon Khanun in the Western Pacific, created the conditions for intense rainfall. The residual circulation of Doksuri’s rain clouds moved northward, blocked by a subtropical and continental high-pressure system, leading to the convergence of water vapour that acted like a dam, storing the water. Additionally, local topographic features in northern China contributed to the extreme weather, lifting the gathered vapour up and causing heavy rainfall in certain regions.
Damages Caused by the Rain:
The impact of the heavy rain was significant in urban areas, flooding hundreds of roads, shutting down parks and tourism spots, and causing delays and cancellations in hundreds of flights. In Beijing’s western suburbs, raging waters swept away cars and cut off access to some mountainous villages. Rescue operations were complicated by the prolonged period of heavy rainfall.
Previous Weather Events:
Such intense rain following weakened typhoons is unusual for Beijing and its surroundings. In the city, typhoons caused significant rain at least 12 times over the years. One of the most notable incidents was Typhoon Wanda in 1956, which unleashed over 400mm of precipitation.
The recent extreme rain and flooding in Beijing, Tianjin, and Hebei Province were unprecedented. They caused severe damage and disruption. The combination of typhoon remnants, air-flows, and local weather patterns created the perfect conditions for the heavy rainfall. Authorities and meteorologists are closely monitoring the situation to better understand and prepare for similar events in the future.