Record heat fuelling violent storms in central US
A sprawling dome of summerlike heat has swelled from Texas to Wisconsin and is poised to shatter temperature records in more than a dozen states.
Since early in the week, the heat has fuelled violent storms in parts of the Upper Midwest and northern Plains, clashing with chillier air lurking near the Canadian border. As more of that cool air attempts to sink south and displace the heat, tens of millions of people face an elevated risk of dangerous storms from west Texas northward.
The most acute risk covers the eastern parts of the Dakotas and western Minnesota, where the National Weather Service Storm Prediction Centre has forecast a level 4 out of 5 threat of severe weather.
For the third time in four days, Minneapolis was under a level 3 ‘‘enhanced’’ storm threat on Friday. Violent storms ripped through the Twin Cities on Thursday, unleashing 110kph to 130kph winds, hail and tornadoes. Tens of thousands of homes and businesses lost power.
Contributing to the storms has been the exceptional heat. A major heat dome of high pressure, flanked by a pair of lows spinning counterclockwise, is parked over the Great Lakes and southeast Canada, and sprawled over the central US. Meteorologists refer to that weather pattern as an ‘‘omega block’’ – the trio of systems interlocking and refusing to budge.
The National Weather Service predicts that dozens of record highs will be set from southeastern Texas to parts of interior Wisconsin and Michigan.
On Thursday, Chicago hit 32C for the first time this year, breaking a record for the date, and the city was predicted to be at least that hot again over the weekend.
Some of the other record-high temperatures set on Thursday included Omaha (35C), Memphis (34C), Nashville and Colorado Springs (33C), South Bend, Indiana (32C) and Milwaukee (30C).
More unseasonable heat looks to be in the offing across the southern US this coming week. Human-caused climate change intensifies the frequency, intensity and duration of such extreme heat.