Possible Derecho threatens the Northern Plains

Daily Mail​

6 days ago

Millions of Americans are bracing for hurricane-force winds as a severe thunderstorm is set to slam into the Northern Plains on Monday. AccuWeather experts said the system could evolve into a derecho, a rare but destructive complex of thunderstorms that is expected to unleash wind gusts of up to 100 mph across four states. The greatest threat zone includes parts of South Dakota, Nebraska, Minnesota and Iowa, which could also experience hail, flash flooding and tornadoes.
The potential derecho is expected to reach its peak strength sometime in the late afternoon or early evening in eastern South Dakota or southern Minnesota. Meteorologist Brandon Buckingham said: 'The high risk of severe weather Monday afternoon through Tuesday morning encompasses a large swath of the 'Corn Belt' of the US, which poses additional economic and logistical risks to the region.' Residents are urged to prepare emergency supplies, including medications, flashlights, batteries and a fully charged cellphone.
Officials recommend seeking shelter in a basement or interior room if a severe thunderstorm or tornado warning is issued. 'People should have multiple ways to receive weather alerts, especially at night when most are sleeping,' AccuWeather said in a statement. 'Do not rely on outdoor sirens alone.' Derechos are defined by straight-line winds exceeding 58 mph across a path of more than 250 miles.
They often topple trees, destroy buildings, and cause long-lasting power outages. A recent derecho in April knocked out power across eastern Ohio and western Pennsylvania for several days. The storm is expected to form over the High Plains, fueled by a dome of high pressure and a surge of tropical moisture.
As thunderstorms initially develop in Montana and the Dakotas Monday afternoon, it is possible for storms to congeal into a powerful derecho,' said Buckingham. 'In turn, AccuWeather meteorologists have added a high risk for severe thunderstorms from eastern South Dakota into southwestern Minnesota and northwestern Iowa.' Major airports, including Minneapolis-St. Paul International, may experience flight delays or cancellations.
Ground transportation could also be disrupted, especially for high-profile vehicles vulnerable to intense wind gusts. Power grids already strained by ongoing heatwaves could face added stress, potentially prolonging outages, AccuWeather warned. A heat dome over the central US is driving the volatile weather expected this week.
Travelers on the road or in the air should be cautious, as the combination of soaring heat and severe storms could cause power outages and disrupt transportation. AccuWeather warned the storm system may continue advancing into the Ohio Valley and Great Lakes on Tuesday, threatening Milwaukee, Chicago and Indianapolis with flooding rain and damaging wind during the morning commute. 'Enough instability may be present across the Midwest Tuesday morning for any complex of thunderstorms to maintain intensity continuing the risks for damaging wind gusts and flash flooding,' adds Buckingham.
By Wednesday, the storm is expected to push into New England and the Mid-Atlantic, where torrential downpours could trigger flash flooding, particularly in areas already saturated from recent storms. Severe weather threats will persist Thursday in parts of the mid-Atlantic as the risk moves south to include the Carolinas.