A historic major winter storm that brought heavy snow over a foot to portions of the northeast and ice more than an inch thick to places in the south will exit the east coast tomorrow, allowing for bitter cold to take its grip over much of the nation east of the Rockies. Because of how cold and dangerous it will be, the National Weather Service has been busy issuing Extreme Cold Warnings to many,

An Extreme Cold Warning is an official alert issued by weather services (such as the National Weather Service) when dangerously low temperatures or wind chills are expected, posing significant threats to life, such as frostbite and hypothermia, within 12–24 hours. It requires immediate action, urging people to stay indoors, cover skin, and limit time outside. These warnings signal that wind chills or temperatures will drop to dangerous levels which are unique to each region they are issued.  Places not used to extreme cold, such as the Gulf of America coastline, can reach local criteria much faster than places in the Upper Midwest where wintertime cold is much more common.

The Extreme Cold Warning is a relatively new advisory in the United States having been released in the fall of 2024. The National Weather Service, at that time, replaced “Wind Chill Warning” with the “Extreme Cold Warning” and a Wind Chill Watch with a “Extreme Cold Watch.”

The Extreme Cold Warning started as an experimental weather warning issued by the National Weather Service in North Dakota, South Dakota, and Minnesota in 2011.  The warning was issued if the temperature fell to −35 °F  or colder with a wind of less than 5 mph. It was an experimental advisory for when the air temperature was dangerously cold, but the wind was too little to warrant a Wind Chill Watch or Warning. In 2018, the National Weather Service announced that based on survey feedback, the Extreme Cold Warning and Wind Chill Warning would be consolidated into an Extreme Cold Warning.  As part of its Hazard Simplification Initiative in 2024, the National Weather Service worked to simplify their suite of cold weather forecast products to improve messaging of winter hazards and provide better decision support to agency partners.

With the winter storm due to exit the coast tomorrow, more Arctic air will spill into the U.S. and  bring bitterly cold temperatures for much of the eastern two-thirds of the country for the next couple of days. In fact, below freezing temperatures will penetrate south of Brownsville, Texas Monday morning, along with below zero readings across the Texas Panhandle and into Oklahoma. These bitterly cold temperatures will be at record-breaking levels across the entire southern Plains. In addition, brisk northerly winds will produce dangerously cold wind chills. More record cold temperatures are expected across the southern Plains into the lower Mississippi Valley Tuesday morning as low temperatures dips into the single digits across the interior Mid-Atlantic, which will challenge some records.

Across the northern Plains to the upper Midwest, frigid temperatures down into the -10s to -20s are forecast for Monday morning. An Alberta clipper will then arrive Monday night before moving through the Great Lakes on Tuesday, bringing snow showers and possibly brief periods of snow squall across the region. Temperatures will moderate some late on Monday before a replenishment of arctic arrives on Tuesday for the northern U.S. The Sunshine State will see below freezing temperatures across the Panhandle/northern Peninsula Tuesday morning.

When the cold air moderates,  the National Weather Service encourages people to take additional steps to recover out of the deep freeze:

• – Check Your Pipes: Your pipes may be frozen. Water pipes on exterior walls and in places that are subject to cold, like in the basement, attic, and under kitchen cabinets, freeze most often. Water expands as it freezes, causing pipes to burst. If they are frozen, first turn on the faucet. Water will drip as you warm the pipes. Heat the pipes using a space heater, heating pad, electric hair dryer, or hot water on a cloth. Never use an open flame. Continue until water pressure returns to normal or call a plumber if you have more issues.
• – Salt Your Walkways: Once it warms up enough to go out, it’s important to shovel the snow from your sidewalks and driveway or sprinkle salt if there is ice. If there is a thick layer of snow on the ground that you cannot move, salt the area so that the snow melts. You should also put down salt if there is ice on the stairs leading into your house – less than a quarter inch of ice can be dangerous!
• – Call Your Neighbors: Check to see that your neighbors are okay, particularly seniors, disabled persons, or others living alone. Carbon monoxide poisoning is one of the leading causes of death after extreme cold, particularly if there are power outages. Cases of frostbite and hypothermia are also common for elderly people who were stuck in their homes.
• – Refill Your Supplies: This cold event may be over, but there might be another one soon. It is important to always be prepared.