A powerful storm system currently centered over the upper Mississippi Valley will drift northeastward and slowly weaken.  However, significant impacts—including cold, snowy, windy weather—will linger into Thursday across the northcentral U.S.  On the northern Plains, post-storm temperatures could fall below 10°F on multiple days, extending into early next week.  Farther south, the threat of severe thunderstorms will shift eastward today, stretching from the lower Mississippi Valley into the central Corn Belt.  By Thursday, any remaining threat of strong thunderstorms will be largely confined to the Atlantic Coast States. 

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