Kentucky and Virginia declare state of emergency

Millions of Americans are anticipating a storm that could bring the most snow and cold weather in a decade.

The storm, which began in the central US, will move eastward in the next few days, the National Weather Service (NWS) said.

A state of emergency has been declared in the states of Kentucky and Virginia, and some parts of the US that are not used to extreme cold, including Mississippi and Florida, have been warned to expect treacherous conditions.

Forecasters say the bad weather will be caused by the polar vortex, which swirls around the Arctic Ocean.

“For some, this could be the heaviest snowfall in a decade,” the National Oceanic and Atmospheric Administration said.

AccuWeather forecaster Dan DePodwin said: “This could lead to the coldest January in the US since 2011.”

He also said that the “low heat” could last for a week.

Lower temperatures will also be on the east coast, where storms are expected to arrive Sunday evening.

In the central US, there will be “severe disruptions to daily life” as well as “dangerous or impassable conditions and widespread closures” through Sunday, according to the NWS.

Parts of Kansas and Indiana could see as much as 8in (20.3cm) of snow.

In parts of the Midwest, storms are possible.

“Clear roads will make travel more dangerous, roads impassable and the risk of motorists becoming stranded,” the NWS warned.

Snow and freezing rain are in the forecast for Missouri, Illinois, and parts of Kentucky and West Virginia.

As the storm moves east, millions of Americans will see lower temperatures, they predict.

Cities including Washington DC, Baltimore and Philadelphia are preparing for winter and snow weather from Sunday through Monday. Between 5-12in of snow could be recorded in parts of Virginia.

Also on Sunday, parts of the southern US including Arkansas, Louisiana and Mississippi could see thunderstorms.

Meteorologist Ryan Maue said: “It’s going to be a disaster, a potential disaster.”

American Airlines, Delta, Southwest and United are waiving change fees for passengers due to flight disruptions.