Tens of Millions of Americans Under Advisories as Heat Wave Builds Across US

A large swath of the United States will be inundated by a heat wave this week, spanning from the West to New England, according to federal forecasters.
“A strong upper-level high [pressure system] is forecast to build eastward across the northern tier states toward New England over the next couple of days,” the National Weather Service (NWS) said in a bulletin on Monday. “The anomalous heatwave underneath this high resulted in all-time record high temperatures across portions of the Great Basin to the northern High Plains on Sunday.”
The NWS stated that as the system moves toward the east, “triple-digit high temperatures will be widespread across the northern Plains over the next couple of days” while heat will soar above 90 degrees Fahrenheit in the upper Midwest Monday before it reaches the Great Lakes and the Northeastern United States on Tuesday. It warned that “increasing humidity” will also accompany the high temperatures….