US sizzles under withering heat that may move west this week | Today’s news

(Bloomberg) — A heat dome is burning across the central U.S., targeting the Great Plains, Midwest and Mississippi River Valley, including Memphis and St. Louis, increasing demand on regional power grids and leaving more than 100 million people struggling.

Separately in the Pacific, Hurricane Fausto is forecast to weaken and pass north of the Hawaiian Islands as a tropical storm on Tuesday and Wednesday, while Hurricane Genevieve strengthens off Mexico’s Baja California coast.

Extreme heat warnings and advisories cover the central US from the North Dakota-Canada border south to Dallas. At least 20 daily high temperature records will be challenged or broken in the region on Sunday, with 33 warm overnight lows also at risk, the U.S. Weather Forecast Center said.

The heat and humidity will cause temperatures to scorch as high as 44C as the heat index rises across large parts of the central US, the National Weather Service said. In St. Louis, where Sunday’s high is forecast to reach 97 F, moisture in the atmosphere could create a feel-good temperature near 116 F, and a high of 102 F is expected in Dallas, with a heat index of up to 109 F.

“A large heat dome is located in the middle of the Rockies and the Plains that will bring record temperatures,” said Alex DaSilva, a meteorologist with commercial forecaster AccuWeather Inc. “Three-digit heat stretches from the Rockies to the Plains. It’s dangerously hot.”

At least 105 million people across the United States are under a heat watch or extreme heat watch for Sunday, including Southern California, the Weather Forecast Center said. As the weather sends people running for relief into air conditioners, Southwest Power Pool and Midcontinent Independent System Operator, which together cover parts of at least 20 states, said loads could increase. Stagnant air beneath a large high-pressure system can also limit wind-generated power at peak times.

High temperatures may hurt some crops but will benefit big retailers as sales of air conditioners and fans rise.

In addition to the steamy temperatures, there is a chance for strong thunderstorms, wind and hail at the edges, DaSilva said. Saturday brought 89 filtered reports of strong winds and two large thunderstorms with hail, mainly in Montana and South Dakota, the U.S. Storm Prediction Center said.

A Category 2 wind and thunderstorm threat is expected again Sunday in the upper Midwest, focusing mainly on Minnesota and Wisconsin, the agency said.

“Whenever you get into these high-pressure areas, you also have to watch the periphery,” DaSilva said. “There will be more opportunities to see bad weather.”

The heat dome will continue to raise temperatures in the western and central U.S. this week before the focus shifts west next weekend, said Bob Oravec, senior branch forecaster for the Weather Prediction Center.

The heat in the Southwest and California will likely last into early August, he said.

In the Pacific, Faust’s main impact is likely to be rough surf and choppy currents on the northern sides of the Hawaiian Islands, AccuWeather’s DaSilva said. “Overall, I don’t think it’s going to be a big problem for them.”

As Fausto weakens, Hurricane Genevieve is strengthening off Mexico’s southwest coast and is potentially on track to become a major Category 4 storm, bringing rough seas to southern parts of the Baja California peninsula, the National Hurricane Center said.

Genevieve is the seventh storm in the eastern Pacific, a mark usually reached on Aug. 11, indicating that the season, which began May 15, is slightly ahead of its normal pace.

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