The US Gulf Coast braces for rare winter storm that brings snow and sleet | American weather

Millions of people across the northern Gulf Coast braced for a rare winter storm on Tuesday that is expected to spread heavy snow, sleet and freezing rain around the Deep South as a blast of arctic air plunges much of the eastern United States into deep freeze .

About 40 million people, primarily across the southern United States from Texas to Florida, were under some form of weather risk, including more than 21 million under a winter storm warning, said meteorologist Marc Chenard of the National Weather Service in College Park, Maryland .

He added that about 170 million people from the Rockies to points east were either under an extreme warning or a cold weather advisory.

The NWS expects between 3 and 7in (7.5-15 cm) of snow and sleet for parts of southern Mississippi and southeastern Louisiana, including New Orleans, heading into Tuesday.

Ahead of the storm, governors in Georgia, Louisiana, Mississippi and Alabama declared states of emergency, and many school systems canceled classes Tuesday.

In Texas, both Houston airports announced flight operations would be suspended starting Tuesday in anticipation of hazardous conditions from the severe winter weather aimed at a large swath in the south.

Residents from Texas to northern Florida rushed to insulate pipes, check heating systems and stock up on emergency supplies.

Elsewhere, the East Coast endured a thick blanket of snow, while people from the northern plains to the tip of Maine shivered in bitterly cold temperatures from the frigid Arctic air mass that sent temperatures plunging well below normal on Monday. Dangerously cold wind chills were expected to continue into Tuesday morning.

Online tracker FlightAware reported nearly 600 flight cancellations Monday night in the United States or entering or leaving the country, along with nearly 6,500 delays. More than 1,700 such cancellations were also announced for Tuesday.

Winter storm warnings extended from Texas to Florida on Monday, with heavy snow, sleet and freezing rain expected around the region through Wednesday.

Meanwhile, a state of emergency was declared Monday night across at least a dozen New York counties as heavy snowfall was expected around Lake Ontario and Lake Erie through Wednesday — with 1-2 feet (30-60 cm) possible — along with extreme cold temperatures.

The storm was expected to affect Texas beginning Monday night, spreading eastward through Wednesday morning with heavy snow expected along and north of the Interstate 10 corridor, with sleet and freezing rain in southern Texas and southeastern Georgia and northern Florida.

Forecasters warned that the sub-freezing morning lows could threaten sensitive vegetation and exposed plumbing in areas unaccustomed to bitter cold.

Across Louisiana, officials urged residents to “stay home” and not “go sightseeing” during the storm, warning that ice on roads could make travel dangerous.

Warming centers were set up as cities sought to get the homeless off the streets. The weather service warned of power outages in areas with significant snow and ice accumulation.

Like earlier this month, this latest cold snap comes from a disturbance in the polar vortex, the ring of cold air normally trapped around the North Pole.