Winter storm, sub-freezing cold descend on US, from Rockies to Atlantic Coast

Snow, sleet and freezing temperatures are forecast for the south, midwest and east coast over the weekend

Workers have been preparing for bad weather (AP)

More than 8,000 flights across the US have been cancelled over the weekend as a major storm bears down on the country, threatening to knock out power for days and snarl major roads.

Snow fell over parts of Texas, Oklahoma and Kansas on Friday in a frosty prelude to a monster winter storm expected to converge with bitter Arctic cold and engulf much of the United States over the weekend from the Rockies to the Eastern Seaboard.