"Completing a day's rainfall in 1 hour": Challenges and responses to Guangdong's new round of severe convective weather

Ask AI · What does the frequent occurrence of severe convective weather in Guangdong have to do with global warming?

On a street where water had overflowed knee-deep, a detached red car rear end floated in the air… Since March 29, another round of severe convection has struck Guangdong, giving a “looking for the owner” post a lot of attention. In the end, thanks to the spontaneous chain of help from well-meaning netizens, Mr. Fan, a resident of Foshan, found the rear end he had lost.

How powerful was this severe convection? It not only swept away Mr. Fan’s car rear end, but also delivered a “high-pressure water-gun style beating” to places like Guangzhou—an amount of rainfall that would take a whole day was poured in within an hour. The onslaught of heavy rain came with thunderstorm gale-force winds and hail. As of 9:48 a.m. on the 30th, across the province there were 37 yellow alerts for torrential rain, 27 orange alerts for hail, and 69 alerts for thunderstorm gale winds in effect.

“Recently, precipitation in Guangdong has been noticeably lower than usual, temperatures are clearly higher than in the same period in history, and it provides very good thermal conditions for severe convection.” Zhang Luqing, chief forecaster at the Guangdong Meteorological Observatory, said this. He analyzed that the atmospheric stratification has been unstable recently, with active warm and humid airflow; fluctuations in the middle layer occur frequently and move eastward. Combined with low-level wind-field convergence and uplift, this leads to severe convection being triggered repeatedly.

During the downpour, a reporter from Nandu N Video noticed that multiple departments in Guangdong—including public security, fire services, and the railway—responded quickly. They cleared tree branches, moved trees, repaired overhead contact lines, and transferred people trapped in dangerous situations—coordinating on multiple fronts to protect people’s lives and safety.

March 29: Netizens posted to look for the owner of the rear end.

Severe convection: In Guangzhou, the amount of rain from one whole day fell within one hour

“Owner of the vehicle with plate number Yue E******, your rear end is looking for you.” On the afternoon of March 29, a netizen on Xiaohongshu posted a photo reportedly located in Qiansdeng Lake, Nanhai District, Foshan. The photo showed the red car rear end fallen onto the street, while the small car was nowhere to be seen. That evening, another netizen updated the follow-up and posted a photo of the car owner and the rear end together.

On the 30th, Nandu reporters managed to reach the car owner, Mr. Fan.

“What embarrassing luck!” he said with a laugh. On the afternoon of the 29th, he drove through Guicheng, Nanhai, and water flooded up to half a tire. “The water’s resistance is big, so I drove a bit too fast.”

Only after he arrived at his destination did he realize that the rear end had fallen off at some point.

“The 4S shop people saw the photo online and even asked me, ‘Is it your back end that fell off?’” Mr. Fan learned that municipal staff picked it up and placed it at the security guard post. “I already reported it to my insurance, and the car is still being repaired.”

Mr. Fan got his rear end back.

This sudden heavy rainfall not only swept away Mr. Fan’s car rear end, but also “brought an end” to singer Xue Zhiqian’s concert.

On the evening of the 29th, due to storm weather, Xue Zhiqian’s concert in Guangzhou was forced to be stopped. Equipment such as lights and screens malfunctioned because it was raining. On site, he announced that tickets could be refunded for everyone.

On the morning of the 30th, a large-scale episode of severe convection once again swept in. Around 8:00 a.m., Nandu reporters were awakened from sleep by the sound of rain and thunder. At that time outside the window, the sky was dim, and daylight felt like night. Dense raindrops struck the glass like a drumbeat.

According to statistics from Guangdong’s meteorological authorities, as of 9:48 a.m. that day, across the province there were 37 yellow alerts for torrential rain, 27 orange alerts for hail, and 69 (10 red, 39 orange, 20 yellow) alerts for thunderstorm gale winds in effect.

From 9:00 a.m. on the 29th to 9:00 a.m. on the 30th, townships and streets in the province that recorded more than 25 mm accounted for 28% of all townships and streets across the province. Five townships and streets recorded more than 100 mm of rain, with truly heavy downpours. Among them: Liaolian Street in Huangpu District, Guangzhou recorded 107.5 mm; Zumiao Subdistrict in Chancheng District, Foshan recorded 105.1 mm; Duyang Town in Yun’an District, Yunfu recorded 104.3 mm; Xianggang Town in Gaoyao District, Zhaoqing recorded 104.1 mm.

Meteorologically, rain with a rainfall amount of greater than or equal to 20 mm within one hour is generally defined as short-duration heavy rain. It is characterized by strong locality, sudden onset, high precipitation intensity, and concentrated precipitation duration. Compared with ordinary heavy rain, it is more potentially dangerous: it increases the load on drainage systems, rapidly triggers urban waterlogging and waterlogged farmland, and may also induce secondary disasters such as flash floods, mudslides and landslides, and collapses.

On the national-level precipitation ranking for meteorological stations at 4:00 p.m. on the 29th, Guangzhou became the place with the strongest rain. Its rainfall in one hour was 54.8 mm—almost a “high-pressure water-gun style beating.” A 24-hour rainfall exceeding 50 mm qualifies as torrential rain, and Guangzhou essentially received the amount of rainfall equivalent to a whole day of torrential rain within just one hour.

Emergency response: Trees pinned vehicles; fire services handled it in time

The fierce severe convective weather temporarily disrupted rail transport and damaged public facilities in both urban and rural areas, affecting people’s travel safety. In many places across Guangdong, departments including railways, public security, and fire services responded quickly, fully投入 into emergency rescue and disaster relief.

At 7:58 a.m. on the 30th, in Gaoyao District, Zhaoqing, the fire and rescue bureau received a call forwarded from 110: on the Ma’an Street area in the direction from Ma’an to Xinqiao, just after passing a traffic light at the Ma’an side, a small car was pinned by fallen trees blown over by strong winds, and two people inside were trapped. The situation was urgent.

Fire and rescue personnel in Gaoyao, Zhaoqing saved the trapped people.

The Xinqiao fire and rescue station immediately dispatched crews to the scene. At 8:05 a.m., the rescue personnel arrived and, after inspection, found that the main trunk of the tree was lying across the vehicle, and the car door could not be opened. The two people were trapped inside. Fire and rescue personnel quickly used equipment such as a portable chain saw to cut the trees and prop them up. At 8:12 a.m., both people were successfully freed and brought to safety; there were no injuries or casualties at the scene. Afterwards, rescue personnel continued to disassemble and clear the fallen trees, and the road was restored to normal flow.

Around 9:00 a.m., a large tree was blown down by the storm in the Zhonghua Middle Road area in Haizhu District, Guangzhou, blocking a lane and making it impossible to pass. Liang Jubiao, a police officer from the Haizhuang Police Station of the Haizhu Branch of Guangzhou Public Security, immediately rushed to the scene. Together with departments such as the Traffic Management Detachment under the Guangzhou Municipal Public Security Bureau, they guided traffic. They waited for the three-defense rescue departments to arrive and handle the situation, and worked hard to fully ensure residents’ travel safety.

Guangzhou police cleared fallen trees.

During the downpour, on-duty traffic police braved the wind and rain. In waterlogged sections of road and beside fallen tree trunks, they set up warning signs, guiding passing vehicles to slow down, avoid the hazards, and detour in an orderly manner. For fallen trees that could not be cleared immediately, traffic police cleared broken branches by hand and worked together to move the trees, doing everything possible to reopen roads that had been blocked.

Around 12:00 p.m., Guangzhou Railway issued a notice. Since the 29th, affected by severe convective weather in the Pearl River Delta region, to ensure the safe operation of trains, the railway department activated its emergency plan at the first opportunity. It dynamically implemented measures on multiple sections of lines such as the Ganzhen-Shen High-Speed Railway (Ganshen), Guangzhou–Shenzhen–Hong Kong High-Speed Railway (Guangshengan?), Guangzhan High-Speed Railway (Guangzhan), and the Guangzhou–Zhuhai Intercity, including short-time line closures and speed-limit operations. Some trains that passed through certain segments experienced delays and cancellations to different degrees.

Railway department personnel are carrying out urgent repairs.

Just the day before, in the afternoon, strong winds blew a steel sheet roof structure along the railway line together with a steel framework beam more than 30 meters long onto the high-speed railway overhead contact line. This caused the overhead contact line between Nanjiang high-speed rail (Nangang?) and the section from Guangzhou South to Foshan West to be affected, and between Guangzhan High-Speed Railway from Foshan to Liyuan? to trip due to foreign objects on the contact line, and some trains experienced varying degrees of delays and cancellations.

After the railway department fully worked on the repairs, as of 6:12 p.m. on the 29th, the foreign objects on the Guangzhan High-Speed Railway overhead contact line were cleared; by 6:35 p.m. for the Nanguang and Guiguan? High-Speed Railway, the foreign objects on the overhead contact line were also cleared. Power supply to the equipment was restored, and train transportation operations gradually returned to normal.

Trend: More extreme weather under the backdrop of global warming

On the afternoon of the 30th, Guangzhou’s thunderstorm weakened, and some areas even saw sunshine—but people still couldn’t afford to be careless.

Guangdong’s meteorological authorities predict that from the 30th to the 31st, due to a squall line, there will be clearly stronger convective weather across the province. From west to east, there will be strong precipitation, thunderstorm gale-force winds (8–10), hail, and other severe convective weather. Locally, winds of around level 12 or even tornadoes may occur. In northern Guangdong and cities/counties in the Pearl River Delta, there will be heavy rain to torrential rain, with some areas seeing extreme torrential downpours. In the other cities/counties, there will be thunderstorms with locally heavy rain. On April 1–2, precipitation will noticeably weaken.

What caused this large-scale episode of severe convection? Zhang Luqing, chief forecaster at the Guangdong Meteorological Observatory, analyzed that in terms of season, spring equinox has already passed; the sun’s altitude angle is higher now, and the sun’s radiant energy toward the ground has increased, which favors surface warming.

“Since mid-March, precipitation in Guangdong has been noticeably on the low side, and temperatures have been clearly higher than in the historical same period, providing very good thermal conditions for severe convection.” He further explained that recently the atmospheric stratification has been unstable, with warm and humid airflow active. Fluctuations in the middle layers occur frequently and move eastward; combined with convergence and uplift in the near-surface wind field, severe convection is triggered repeatedly. Cold, dry air with larger momentum in the middle layers is drawn in, causing evaporation-related cooling. The dragging effects of strong precipitation and hail, along with strong downward motion, then lead to surface strong winds.

On March 30, residents of Guangzhou riding on a bridge wearing raincoats. Photo by Nandu N Video reporter Wei Juanming.

This is the first large-scale episode of severe convection this year—and it’s only the beginning. According to “China Weather,” the rainy situation across southern China this week will continue. Three rounds of strong rainfall and severe convective processes (March 29–31, April 2–4, and May 5–7) will appear one after another.

At present, Guangdong has entered a season when severe convection and heavy precipitation occur frequently. And before this round of severe convection arrived, Guangzhou announced it had already entered summer on March 19—the earliest since 1961.

Online, there have also been claims like “an ultra-strong El Niño will cause this year to be the hottest year.”

Liu Chang, chief of the Guangdong Climate Center, told Nandu reporters that it is still too early to assert that “this year will be the hottest year in history.” Climate forecasting has significant uncertainty, and continuous monitoring is required.

She also reminded that under the backdrop of global warming, extreme weather events are trending upward. If it enters an El Niño state, a strong El Niño will further intensify this pattern—“making the risk of extreme events in Guangdong such as typhoons, heavy rainfall, high temperatures, and droughts clearly rise.” Overall, due to its influence, Guangdong’s flood season precipitation will be noticeably phased, with a high probability of flooding and waterlogging disasters.

Produced by: Nandu Instant

Overall coordination: Xiang Xueni; Wei Juanming

Reporting and writing: Nandu N Video reporters Wei Juanming, Li Sixihan, Yang Ting