Parts of US may see up to 12 inches of snow with ‘life-threatening cold air’

A powerful blast of cold air from the Arctic is expected to sweep through much of the United States over the coming days, with some areas expected to see more than 12in (30cm) of snow before the weekend is over.

The National Weather Service (NWS) expects “life-threatening cold air” to slowly track from the High Plains and Rockies in an eastward direction from Friday, bringing snow and ice to around 160 million people across 30 states.

Meteorologists say temperatures could plunge well below freezing in some areas.

Separately, snow showers are already affecting an area of the US downwind of the Great Lakes, which span the US-Canada border.

US transportation officials, including airport authorities in several major cities, are warning travellers to brace for significant delays as the severe weather system moves across the US over the weekend.

That weather system is expected to take shape in Texas and New Mexico before moving eastward, blanketing cities including Memphis, Nashville, Washington DC, Baltimore, Philadelphia and New York with snow.

The NWS says the coldest wind chills may fall below -50F (-46C) across the Northern Plains, with a much wider area of the south-eastern US also experiencing sub-zero chills.

“These wind chills will pose life-threatening risk of hypothermia and frostbite to exposed skin,” the NWS warned.

While it remains too early to predict exact snowfall totals in urban areas, some places are expected to see over 12in (1 foot), weather experts have said.

According to the NWS Probabilistic Precipitation Portal, the regions that could see more than a foot of snow stretch from Colorado to West Virginia to upstate New York.

In a few other states, including Kansas, Oklahoma, Arkansas, Missouri, Kentucky and Indiana, snow totals could reach depths of 12 inches.

States further south may experience freezing rain, which could coat trees with ice and weigh them down, possibly leading to power outages. Some localised flooding could also occur as thunderstorms dump moisture into lowland areas.

Some airlines have offered passengers the option to change their flights, in some cases without incurring extra fees, due to concerns about cancellations.

Canada is experiencing freezing temperatures of its own, and eastern and Atlantic regions could experience snowfall, meteorologist Geoff Coulson said. But Coulson said it was too soon to say how big the impacts could be.

Governors in several US states, including Arkansas, Georgia, Texas, North Carolina, South Carolina, have declared states of emergency, allowing emergency officials – including National Guard troops – to begin mobilising response efforts.

“Based on current forecasts, the State of Texas is acting to ensure Texans have the resources they need before severe winter weather impacts communities across Texas,” Texas Governor Greg Abbott said in a statement on Tuesday.

The warnings come amid memories of the bitterly cold winter storm that struck Texas in 2021, causing the energy grid to fail and leaving millions of residents without power for several days.

Officials caution the cold temperatures could again cause pipes to freeze and then burst.

Roadways could also be blocked for days, especially in southern states with limited de-icing equipment.

Cold temperatures are expected to persist into next week.