The National Weather Service said temperatures could reach 100 degrees Celsius on Sunday, from the Gulf Coast to near the twin cities of Minnesota, where “dangerous heat and humidity” were expected. A heatwave that burned southwest last week and brought record temperatures to more than a dozen cities has remained, moving steadily east and settling in the plains on Sunday, said Marc Chenard, a meteorologist with the National Weather Service. The heatwave is expected to continue during the week. “The heat is definitely related to the general pattern we’ve seen in most US go back a week,” Chenard said. “And in fact it is going to continue for another week or so.” Some records were set on Saturday along the central Gulf Coast, where temperatures reached 98 degrees in Tampa, Florida and 101 degrees in Mobile, Ala, according to the Meteorological Service. As of Monday, the heat dome is expected to move into the Mississippi Valley and mid-South, the Meteorological Agency said. By Tuesday, it will shift to the Great Lakes and the Ohio and Tennessee valleys, and then southeast through Wednesday, Chenard said. Temperatures in much of the country will be above average during the week, Mr Chenard said, adding that “quite possible record highs” could be set across Texas and much of Southeastern Europe. Since then, heat waves have erupted in the southwest, where “humidity of the early monsoon season” was expected to cause flash floods and scattered thunderstorms on Sunday, the Meteorological Agency said. Temperatures in California and Nevada were significantly lower on Sunday, with possible record lows falling to 40 degrees just a week after both areas were heated under the heat wave. On Sunday, red flag warnings covered large parts of Arizona and Utah. Six fires, covering a total of more than 53,000 acres, remained active in Arizona, according to the National Interdepartmental Fire Department. Fire conditions are expected to improve on Monday, the Meteorological Service announced. Heat waves are more frequent and warmer and last longer than in previous decades, and are part of a global warming trend, scientists say. The average number of heat waves in the United States has tripled from two per year in the 1960s to six in the 2010s, according to the federal National Climate Assessment. The heat wave is also 45 days longer than it was in the 1960s.
