A brutal winter storm has dumped snow, sleet and freezing rain up the south-east seaboard of the United States, delivering snowy conditions some cities had not seen in decades.

Weather system Hermine has weakened to a tropical storm as it moves inland after making landfall in Florida's Big Bend area as a hurricane.

Hurricane Hermine gained strength as it roared towards Florida's Gulf Coast, as residents were warned to flee inland if necessary amid a "life-threatening situation".

Residents on Florida’s Gulf coast filled sandbags, schools planned to close early, and governor Rick Scott declared a state of emergency as Tropical Storm Colin gained speed and churned towards the state, threatening serious flooding.