A shifting, early-season heat wave will refocus across the Plains later this week, allowing cooler air to temporarily overspread the middle Atlantic and Midwestern States.  Much of the nation’s mid-section, from eastern Montana and the Dakotas to Texas, should experience weekend high temperatures near or above 100°F.  By early next week, however, heat will again spread eastward, with triple-digit temperatures potentially returning across the mid-South, Midwest, and Southeast.  In contrast, cool weather will linger in the Northwest, accompanied by scattered showers as a Pacific storm system moves inland. 

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