A deadly winter storm is likely to affect one third of the US, threatening to lay a potentially deadly path of heavy snow and ice from the Rockies to New England, the Associated Press reports.

Over millions of people are likely to be affected by the winter storm and cities like Milwaukee, St. Louis and Kansas City are expected to be hit the hardest.

On Sunday, the National Weather Service had issued an emergency blizzard warning stating that over 18 inches of snow are expected to impact portions of Northern Illinois and Northwest Indiana.

The two-staged storm which has already hit parts of the US has led to cancellations of a number of flights operating in the area.

 "A storm of this size and scope needs to be taken seriously," Bloomberg quoted Craig Fugate, administrator of the Federal Emergency Management Agency, saying in an e-mail yesterday. "Already this winter we've seen how snow and ice can knock out power and affect transportation. If you haven't already, take steps now to get your homes and families ready, and be sure to check on your neighbors, especially the elderly and young children -- those who can be most vulnerable during emergencies."

If predictions by the weather service come true, the winter storm could very well be the third-biggest to affect the city after the 1999 and 1967 snow storms.