Weather extremes in US connected, scientists say
As the Western U.S. bakes and burns under an unprecedented heat dome, Henri leaves a deluged East Coast staggering after a summer of deadly floods and record-setting tropical storms. Climate scientists say one is due to the other and both come against the backdrop of a warming planet.
The high pressure that got stuck across the West causing drought and fire created the conditions for lowpressure-driven storms in the East. So while July was the hottest month ever recorded on Earth, it was the sixth wettest in U.S. records going back 127 years, according to the National Centers for Environment Information.
Jim Rouiller, lead meteorologist at the Energy Weather Group, said heat in the Pacific and the Atlantic has helped strengthen large high pressure systems. In the West, that has added to the drought and wildfires; in the East, it has steered tropical systems up the coast and kept the region warm and moist. In between has been a low-pressure trough that has kept the rain falling across the central and eastern U.S.
Abnormally warm water in the Atlantic has been providing extra moisture to the storms, said Paul Pastelok, a meteorologist with commercial forecaster AccuWeather Inc.
As of Monday, at least 22 people died in flooding in Tennessee, according to Humphreys County Emergency Management Agency representative Grey Collier. Record rains dropped more than 17 inches in McEwen, along with more than 10 inches across a wide section of the state.
Tropical Storm Fred last week dumped more than a foot of rain on North Carolina, where 98 people had to be rescued, according to Gov. Roy Cooper. At least four have died, according to news reports.
The East Coast’s summer has felt like a list of uninvited guests: Tropical Storms Claudette, Danny, Fred and Henri, as well as Hurricane Elsa. In fact, Henri was the latest in a grim parade of extreme weather events worldwide. Massive wildfires have blackened not only huge swaths of California, but also Greece, Algeria and Siberia, sending smoke over the North Pole for the first time on record.
Earlier this month, Sicily appears to have broken continental Europe’s heat record: 119.8 Fahrenheit. The U.K. Met Office issued its first-ever extreme heat warning.
As wildfires hit eastern Siberia, western and central Russia were cold.
Meanwhile, floods have plagued northern Europe, killing scores in Germany and Belgium and causing billions of dollars of damage. In Germany, July’s rain and flooding were the worst natural disaster since the 1960s.
Back in the U.S., extreme has simply become ordinary. A spate of tornadoes ripped through suburban Philadelphia. Boston had its wettest July on record. The high in Portland, Oregon, hit 116 degrees in June.
Through the first six months of 2021, the U.S. has suffered eight disasters costing $1 billion or more that have also killed 331 people, according to the National Centers for Environmental Information. The worst disaster was last February’s winter storm that crippled the Texas electric grid and killed at least 172 people and cost $20.4 billion.