Emergency dispatch by two departments: resolutely and decisively stop work, close down business, etc., rainstorm red alert was issued in Beijing, and the residual circulation of "Dusurai" moved northward | Beijing | Department

Chief Forecaster of Beijing Meteorological Observatory's Analysis of the Impact of "Du Suri" on Beijing

01

Why did "Du Suri" affect Beijing?

Zhang Linna, Chief Forecaster of the Beijing Meteorological Observatory: Whether a typhoon generated in the northwest Pacific will affect Beijing largely depends on its path, and its path depends more on the shape of the entire atmospheric circulation. Therefore, when making forecasts, we also pay more attention to the overall situation of the atmospheric circulation.

02

What impact will "Du Suri" have on the weather in Beijing? How long will it last?

Zhang Linna, Chief Forecaster of the Beijing Meteorological Observatory: Typhoon Du Suri made landfall along the coast of Fujian on the morning of the 28th and weakened to a tropical depression at 11:00 on the 29th. The Central Meteorological Observatory also stopped numbering it. Although its numbering has stopped, the form of the low-pressure circulation still exists.

Due to the continuous influence of low-pressure circulation and its interaction with other weather systems during its movement, the southward warm and humid airflow around the subtropical high will further strengthen. The weakened low-pressure circulation and southward warm and humid airflow around the subtropical high will combine well in the Beijing Tianjin Hebei region, bringing a heavy rainfall to Beijing and a large area of the Beijing Tianjin Hebei region.

With regard to rainfall, we expect that from the night of 29th to August 1st, Du Suri will bring a heavy rainstorm to Beijing. The weather process of extremely heavy rainstorm in some areas, in which the 30th and 31st are the main stages of rainfall, and there will be a northerly wind of six or seven degrees when the heavy rainfall occurs. So for this rainfall process, the Beijing Meteorological Station has issued a red warning signal of rainstorm.

03

In terms of historical meteorological records, have typhoons had a significant impact on Beijing?

What is the extent of Du Suri's influence on Beijing in history?

Zhang Linna, Chief Forecaster of Beijing Meteorological Observatory: From meteorological records, there were only 23 typhoons that weakened their low-pressure circulation during the period from 1949 to 2022, affecting Beijing. On average, 0.31 typhoons affected Beijing each year. The impact of the weakened low-pressure circulation in Dussuri on Beijing this time should be said to be very extreme. Based on our current forecast, it is highly likely that the impact of Typhoon Dussuri on precipitation in Beijing will rank first or second, indicating a significant impact.

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The residual circulation of Typhoon "Dussuri" will move northward, and extreme heavy rainfall will occur in Beijing, Tianjin, Hebei, Shandong, Henan, and Jin provinces

Radar monitoring shows that due to the continued northward influence of the residual circulation of Typhoon Dussuri, precipitation clouds are gradually moving northward, and there will be heavy rainfall in North China, Huanghuai and other areas. The China Meteorological Administration launched a Level 1 emergency response for major meteorological disasters on the 29th.

According to the forecast of the Central Meteorological Observatory, from July 29 to August 1, there will be heavy rainstorms in Beijing, Tianjin, Hebei, western Shandong, northern Henan and eastern Shanxi, and extremely heavy rainstorms in the western and southern parts of Beijing and central and southern Hebei. The accumulated rainfall in the above areas is 50 to 150mm, and 200 to 450mm in parts of Beijing, Tianjin and Hebei, with local rainfall of more than 600mm. The maximum hourly rainfall is 30 to 60mm, local up to 80mm or more. The main precipitation period is from the night of July 29 to 31.

Experts said that this round of rainfall has the characteristics of long duration, wide range of influence, and large accumulated rainfall. It is estimated that the cumulative rainfall of more than 100mm will reach 220000 square kilometers, which will affect the 0.13 billion of the population. The intensity may be close to or exceed the "July 21" Beijing rainstorm in 2012 and the rainfall process from July 18 to 20, 2016. The extreme is strong and the risk of disaster is high.

Why can "Du Suri" travel a long distance after landing, causing extreme heavy precipitation in the north?

Fang Chong, chief forecaster of the Central Meteorological Observatory, said that the long duration of the residual circulation, the abundant water vapor transport, and the terrain blessing have jointly caused the extreme heavy precipitation in the Beijing-Tianjin-Hebei region.

"Du Suri" was strong when it landed, and the speed of northward was once faster after landing. The precipitation caused by Jiangxi, Anhui and other places was not too strong. it is expected that the "du suri" residual circulation will enter henan on the night of the 29th. "As the Beijing-Tianjin-Hebei region is on the north and northeast sides of the circulation, there is a subtropical high pressure entrenched westward in the eastern part of North China, while there is a high pressure ridge gradually moving eastward in the west, the high pressure on both sides may open up on the evening of the 29th, forming a 'high-pressure dam' in the northern part of North China, slowing down the speed of the residual circulation to continue northward. Therefore, the circulation in the Huanghuai area, the circulation continues to increase." Fang Chong said.

On the other hand, "Du Suri" itself carries a lot of water vapor, and its east side is a subtropical high. The strong pressure gradient between the two will cause the east wind and southeast wind in the Beijing-Tianjin-Hebei region to increase significantly. The strong southeastern wind will continuously transport the water vapor near Typhoon "Kanu" in the western Pacific to the North China Plain, and the water vapor conditions are very abundant.

In addition, the Taihang Mountains in the west of Beijing, Tianjin and Hebei intersect with the east wind and southeast wind carrying water vapor in a positive direction, and the Yanshan Mountains in the north also intersect with the water vapor channel. The water vapor is blocked by the terrain and uplifted, and is concentrated in the front of the mountain to form extreme heavy precipitation.

Experts said that the rainfall process in the Beijing-Tianjin-Hebei region is affected by a fixed weather system for a long time. For example, when people stand next to a moving train, they continuously feel the huge sound and impulse brought by the passing of a carriage. The effect is superimposed, which is often called the "train effect".

Meteorological experts reminded that the public in Beijing, Tianjin, Hebei, Henan, Shandong, and Shanxi should pay attention to changes in rain and flood conditions and take relevant preventive measures. Do not go to areas prone to geological disasters, and do not wade rashly when encountering stagnant water.

The Emergency Department of the National Defense Bureau has dispatched heavy rainfall in the northern region and resolutely implemented the "five shutdowns" of work stoppages, shutdowns, and business closures

On July 29th at 22:00, the General Office of the People's Republic of China and the Ministry of Emergency Management organized a meeting and scheduling with the China Meteorological Administration and the Ministry of Water Resources to discuss and assess the development trend of heavy rainfall in the northern region and the losses caused by typhoon disasters in Fujian. They also made video connections to the prevention and control offices of provinces such as Beijing, Tianjin, Hebei, Henan, and Fujian to analyze and assess the development trend of heavy rainfall in the northern region and the losses caused by typhoon disasters in Fujian. They arranged and deployed flood prevention and disaster relief work. At present, the National Flood Control Administration maintains a three-level emergency response to flood control in the Beijing Tianjin Hebei Jin Lu Yu region. In addition to dispatching 12 flood control working groups in the early stage, an additional 3 working groups are dispatched to relevant areas to assist in guiding disaster relief and rescue work.

According to the introduction of the National Flood Control Administration, the heavy rainfall process in the northern region is currently the top priority for prevention and response. In the coming days, some rainy areas will overlap and accumulate large amounts of rainfall. In addition, the weak foundation of prevention and response in the northern region will lead to a severe and complex situation in flood control and disaster relief. We must make every effort to do a good job in preventing and responding to extreme heavy rainfall, and effectively prioritize the safety of people's lives and property.

Not only should we pay attention to floods in rivers such as Yongding River, Juma River, and North Canal, but we should also focus on weak links such as mountain flood geological disasters, urban waterlogging, and flood prevention in small and medium-sized rivers. We should strengthen risk assessment and emergency preparedness, and strengthen the flood control responsibilities centered on the administrative head responsibility system. We need to strengthen the short-term warning and "response" mechanism, and for high-level warnings, the responsible persons of relevant flood control command institutions and town and village flood control responsibilities should be awakened in a timely manner to ensure that warning information is implemented and measures are implemented to individuals.

We need to promptly initiate emergency response, make real-time dynamic adjustments, resolutely and decisively take rigid measures such as "five stops", and organize dangerous area residents to evacuate and avoid danger in advance. We should focus on risk investigation, rectification, and patrol defense, closely defend key infrastructure and key unit locations, comprehensively inspect high-risk areas such as campsites, cross ditch roads, bridges and culverts, and small and medium-sized reservoirs under construction, leaving no loopholes or blind spots, and resolutely avoid mass casualties. Emergency rescue forces and equipment should be pre-set in advance, and emergency situations should be handled in a timely manner to minimize disaster losses.

As of now, the national comprehensive firefighting and rescue team has participated in 804 flood control and rescue operations, dispatched 5481 firefighting and rescue personnel, 855 vehicles, and 533 boats, rescued 1260 people in distress and trapped, and evacuated and transferred 2323 people. At the same time, 2226 firefighters and 423 fire trucks were on standby at 215 duty points in 18 provinces.