A massive winter storm headed towards the northeast United States on Sunday after sweeping across much of the country, threatening tens of millions of Americans with blackouts, transportation chaos an

The latest forecast from the National Weather Service's Houston/Galveston office is sharpening the threat of a prolonged and potentially dangerous freeze as an Arctic air mass settles over Southeast Texas this weekend.

The winter storm warning for the Houston area has expired. Now, attention turns to the icy roads that remain and the bitterly cold temperatures that are expected Sunday night into Monday morning.