Deadly episodes of flash flooding causing chaos around the world

Numerous occurrences of torrential downpours have wreaked havoc at different ends of the Earth since the beginning of September, leading to major flooding and dozens of deaths. According to AccuWeather forecasters, more flooding downpours are ahead for millions around the world into next week.

The flood events, stemming from many storms striking in recent days in Brazil, southern Europe, eastern Asia and the western United States, have all bore in common the same thing: a quick onset of heavy rain that lasts for an extended amount of time, leading to flash flooding where time to escape rising waters is scarce.

Numerous records have fallen from the recent flood events over the past week, including an all-time daily rainfall record for Greece and the all-time 1-hour rainfall record for Hong Kong.

Floodwaters cover a suburb after the country's record rainstorm, in Larissa, Thessaly region, central Greece, Friday, Sept. 8, 2023. Widespread flooding in central Greece has left several people dead and others missing, with severe rainstorms turning streams into raging torrents, bursting dams, washing away roads and bridges, and hurling cars into the sea. (AP Photo/Vaggelis Kousioras)

While individual events usually cannot be linked to climate change, the collection of many can, as studies have shown that increased evaporation from rising global temperatures can lead to more intense precipitation events.

Amid winter in Brazil, a storm moving across the South American continent since Monday night, local time, has unleashed heavy rain and flooding in the country. At least 39 people have lost their lives in the flooding, which has stretched across more than 70 cities and displaced more than 6,000 people, according to Brazil Reports.

"I had never seen the city with so many floods, houses and companies destroyed, entire neighborhoods affected," Júlio Saldanha, a long-time resident of Estrela, Brazil, told the online news website.


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Hit hardest by the storm was Rio Grande do Sul, Brazil's southernmost state. Rain gauges in the area registered close to 4 inches (100 mm) of rain in a short amount of time, and there were also reports of strong winds from the storm of up to 68.4 mph (110 km/h), Reuters reported.

"An area of low pressure developed along a slow-moving front, which led to the torrential rainfall across southern Brazil and into portions of northern Uruguay last week," AccuWeather Senior Meteorologist Adam Douty said.

A family is transported in a tractor through a flooded street in the Ilha da Pintada neighborhood of Porto Alegre, Rio Grande do Sul state, Brazil, Thursday, Sept. 7, 2023. Flooding from a deadly cyclone in southern Brazil has washed away houses, trapped motorists in vehicles and swamped streets in several cities. (AP Photo/Wesley Santos)

The flooding forced the cancelation of Brazil Independence Day parades in the affected area and a declaration of a state of public calamity by the state's governor Eduardo Leite.

A video posted to social media showed a toddler being rescued by helicopter from the roof of a house near the flooded Taquari River. According to CBS News, in Mucum, a city along the same river with 50,000 residents, 15 bodies were found in just one house, as rescuers scoured through a trail of destruction where most buildings were completely swept away by floodwaters.

"The heaviest rain has since moved on from the area," added Douty. "The front remained draped across southern Brazil into late Friday, resulting in additional rain and thunderstorms across the region on Saturday."

From Thursday night into Friday, a round of heavy rain in Hong Kong and southeastern China led to record and deadly flooding. AccuWeather's team of international forecasters warns that the region may see additional heavy rain into early week.

The Hong Kong Observatory reported between around 27.5 and 31.5 inches (700 and 800 mm) of rain from Thursday into Friday in parts of the city, including an all-time one-hour record of 6.2 inches (158.1 mm) between 11 p.m. and midnight local time. Records for the city date back to 1884.

A shopping mall is flooded following heavy rainstorms in Hong Kong, Friday, Sept. 8, 2023. Rain pouring onto Hong Kong and southern China overnight flooded city streets and some subway stations, halting transportation and forcing schools to close Friday. (AP Photo/Louise Delmotte)

The tremendous rainfall rates led to a torrent of floodwaters in the streets of the city, which inundated metro stations and parking garages and led to collapsed roads, according to CNN. The Associated Press attributed at least two deaths to the flooding.

A further 110 people were evacuated from the flooding, and at least 20 people were injured, said the AP.

"Rounds of heavy rain are expected to fall across southern China and Taiwan through the weekend," warned Douty. "This can lead to additional flooding."

Another 4 to 8 inches (about 100-200 mm) of rain can be expected between Friday night and Sunday night, local time, from southern Guangdong province, China, into the mountains of southern Taiwan, according to AccuWeather forecasters. The AccuWeather Local StormMax™ for the region is 35 inches (about 900 mm).

Following a summer full of devastating wildfires, Greece and surrounding Balkan nations have had to endure heavy rain and flooding as of late, as Storm Daniel moved through from Tuesday through Thursday of this week.

According to CNN, at least 14 deaths were attributed to the storm's flooding rains, which also impacted Bulgaria and Turkey. In Thessaly, Greece, more than 1,900 water rescues occurred on Thursday alone, according to Financial Times (FT), as floodwaters swept through the ancient city.

A damaged house stands over the water after the country's record rainfall in Horto village, Pilion region, central Greece, Wednesday, Sept. 6, 2023. Rescue teams in Turkey, Greece and Bulgaria have recovered more bodies following floods after fierce rainstorms. (AP Photo/Thodoris Nikolaou)

In Zagora, Greece, 29.68 inches (754 mm) of rain fell in a single day from the storm, setting a new 24-hour rainfall record for the entire country. That beats the old record of 25.38 inches (645 mm) set in Paliki in September of 2020.

The dangers posed by the flooding from Storm Daniel were winding down in Greece late Friday. FT reported that evacuation orders had been issued along the Pineios River, which was starting to overflow its banks. The General Staff of National Defense announced that the armed forces evacuated over 2,000 residents due to flooding across the Thessaly region of Greece late last week and this weekend.

As Storm Daniel continues to track southward across the Mediterranean Sea through Sunday, conditions will continue to improve over the Balkans.

"Heavy rain from the storm will still impact portions of Northern Africa into the weekend," added Douty.

Separate rounds of heavy rain in Nevada made national headlines earlier this week, impacting both the Burning Man desert campout in the northwestern part of the state and the city of Las Vegas in the south.

In the Black Rock desert near Reno, home to Burning Man, tens of thousands of people attending the event were stranded by sudden downpours and mudflows last weekend. Shelter-in-place orders were issued for a time before a mass exodus of attendees occurred this week.

A person walks through floodwaters near a stranded car, Friday, Sept. 1, 2023, in Las Vegas. (AP Photo/John Locher)

The Sheriff's Office in Pershing County confirmed earlier that one person died at the event, but the cause of death remains under investigation, according to Axios.

The flooding and heavy rain led to the delay of the event's annual culmination, the burning of the "man" totem, initially scheduled for Saturday. That burn eventually began on Monday night, amid the start of hourslong departures from the event site.

Meanwhile, farther south in Las Vegas, one person died in floodwaters that swept through the city on Friday from a round of heavy monsoon rains. Local TV station KSNV identified the victim as a 13-year-old teenager.

The Las Vegas Strip was also impacted by the flooding, which was caused by more than 2 inches of rain falling in a very short amount of time. At Harry Reid International Airport, 0.88 of an inch of rain fell on Sept. 1, nearly three times the average amount of rain for the entire month, and the wettest single day since September 2012.

Much quieter weather has settled over Nevada since the heavy rain events, according to AccuWeather forecasters. In Las Vegas, sunshine and temperatures near the 100-degree mark can be expected nearly every day into next week while the Black Rock area will also be dry for the next week.

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