An unusual nasty mix of a hurricane and a winter storm that forecasters are now calling "Frankenstorm" is likely to blast most of the East Coast next week, focusing the worst of its weather mayhem around New York City and New Jersey.

Government forecasters on Thursday upped the odds of a major weather mess, now saying there's a 90 percent chance that the East will get steady gale-force winds, heavy rain, flooding and maybe snow starting Sunday and stretching past Halloween on Wednesday.

The storm is a combination of Hurricane Sandy, now in the Caribbean, an early winter storm in the West, and a blast of arctic air from the North. They're predicted to collide and park over the country's most populous coastal corridor and reach as far inland as Ohio.