Where did the cold front come from?

(29)A cold front moving down from Canada and butting up against moisture out of the Gulf of Mexico has produced freezing rain, snow and flash floods from Kansas down to Texas and eastward into Missouri.(30)Cars and trucks skidding on icy roads have caused dozens of serious accidents, particularly in northern Texas and across Oklahoma. Seven Mexican nationals died on an icy road in western Oklahoma when the van they were in was hit head-on by a large truck.