Major cities in US facing heatwave, taxing power grids

NEW YORK • A vast swathe of the United States will face dangerously high temperatures this week, with severe heat baking major cities and taxing power grids across the country.

"This is the strongest heat we've seen all summer" with 170 million people under advisories, said Mr Jim Rouiller, lead meteorologist at the Energy Weather Group. "There will be many records set."

Warnings and advisories stretched across the Pacific Northwest, the east coast and 17 states in the south and Midwest, according to the National Weather Service.

Humidity in the east was expected to exacerbate the heat, making it feel like 41 deg C in New York yesterday and 43 deg C in Washington.

This year has been defined by extreme weather, with a February storm triggering an energy crisis in Texas, record-setting June temperatures in the Pacific Northwest and California currently struggling to extinguish the second-largest wildfire in state history.

It is all linked to climate change and this week's heatwave comes on the heels of a landmark United Nations report warning of catastrophic weather shifts without immediate action to rein in carbon emissions.

The heat will not start to ease until the weekend, said Mr William Churchill, a forecaster at the US Weather Prediction Center.

Some of the most serious warnings covered major cities including Seattle, Philadelphia and St Louis, where temperatures do not fall as much after sundown because streets and buildings tend to retain heat.

"That could be more deadly because you don't get that relief at night to cool you down, and then the heat comes back the next day," Mr Churchill said.

It is unusual to see so much of the US facing extreme heat at the same time, said Mr Rouiller. That is going to stress power grids as millions of people turn up their air conditioning.

Operators are already taking steps to make sure the lights stay on. PJM Interconnection, which oversees the biggest US grid stretching from Chicago to Washington DC, issued a hot weather alert for Wednesday and yesterday, asking power companies to limit repair work.

California's grid operator is also asking power plant owners to restrict maintenance through today to ensure there is enough capacity. New York's operators had an alert in place seeking additional power import capacity from neighbouring grids for Wednesday afternoon.

"It's extremely hot, almost from coast to coast," Mr Rouiller said.

BLOOMBERG

170m Number of people who are under heat advisories in the US this week.