By PATRICK WHITTLE and BRIAN WITTE A blast of snow, ice, wind and plunging temperatures stirred up dangerous travel conditions in parts of the central U.S. on Sunday, as a disruptive winter storm brought the possibility of the “heaviest snowfall in a decade” to some areas. Snow and ice blanketed major roadways in nearly all of Kansas, western Nebraska and parts of Indiana, where the state’s National Guard was activated to help any motorists who were stuck.