SPOKANE, Wash.—The unprecedented Northwest U.S. heat wave that slammed Seattle and Portland, Oregon, moved inland Tuesday—prompting an electrical utility in Spokane, Washington, to warn that people will face more rolling blackouts amid heavy power demand. The intense weather that gave Seattle and Portland consecutive days of record high temperatures far exceeding 100 degrees Fahrenheit was expected to ease in those cities. But inland Spokane was likely to surpass Monday’s high temperature—a record-tying 105 F. About 8,200 utility customers in parts of Spokane lost power on Monday and Avista Utilities warned that there will be more rolling blackouts on Tuesday in the city of about 220,000 people with the high temperature predicted at 110 F, which would be an all-time record. Avista had planned for much higher than normal demand but hit its limit quicker than anticipated because of the intense heat, said Heather Rosentrater, the company’s senior vice president for …