Arctic Airmass Descends Over Continental US, Bringing Extreme Cold

Below-freezing conditions are forecast for 75 percent of the United States over the next few days.

Temperature forecasts for Jan. 14, 2024. NOAA/NWS

A blast of arctic air descending over the continental United States will see temperatures drop to the minus 30s early this week as winter makes a late but unmistakable arrival.

After a week of winter storms, another low-pressure system in the northern Pacific is clashing with a frigid Arctic air mass that is pushing south over the continent from western Canada and is expected to bring the coldest conditions yet this season.

Below-freezing conditions are forecast for 75 percent of the United States over the next few days. More than 30 million residents from California to New York were under winter weather advisories on Saturday.

The National Weather Service (NWS) has warned residents from the west to east coast to prepare for the arrival of some life-threatening conditions due to wind chill. Montana has already seen temperatures plummet to below -30 degrees Fahrenheit (-34 degrees Celcius).

Wind chill in Montana and across the western Dakotas could take ambient temperatures as low as negative 50 degrees F, posing a risk of frostbite as well as hypothermia, forecasters said. Frostbite can occur in as little as 10 minutes on exposed skin under these conditions.

Extreme wind chill of minus 71 degrees F was recorded in Navajo, Montana, on Saturday morning.

The arctic conditions have also been seen in the Northern Rockies to northern Kansas and into Iowa.

The NWS in Des Moise, Iowa, warned of “Life Threatening Wind Chills” in a Saturday update. “This Arctic air combined with breezy to strong winds will create dangerous temperatures and wind chills through early next week, with wind chill values as low as 45 below zero possible at times.”

On Saturday night, wind chills saw conditions drop to as low as -40 degrees F across western Iowa. Wind chill of -34 degrees F was recorded in northern Missouri. The icy conditions are soon expected to reach Colorado to Indiana.

Further south, temperatures in Denver dropped from 33 degrees F on Friday to 10 degrees F on Saturday, and are forecast to dip to 5 degrees F Sunday. The wind chill Sunday morning in Denver is expected to be as low as minus 20 degrees F. A wind chill warning for dangerously cold wind chills as low as 40 below zero F remains in effect until 11 a.m. Tuesday local time.

More heavy snowfall from the new winter storm system was seen on the West Coast into the Rockies on Saturday, increasing avalanche danger.

“Heavy snow, blowing snow, and valley icing will all contribute to poor to impossible travel from Oregon, Idaho, Nevada, and Utah, including the Portland, Boise, and Salt Lake City metro areas. Significant freezing rain is expected today over western Oregon, with tree and powerline damage possible,” the NWS said in a post on X, formerly Twitter, on Saturday.

Icerinks in Portland were closed as they became unusable after five inches of snow blanketed the city for the Martin Luther King Jr holiday weekend.

Heavy snow is also forecast for areas downwind of the Great Lakes through midweek, bringing another 12–24 inches of snow through Monday.

Up into the middle of the week, sub-zero wind chills are forecast to spread and potentially reach areas as far south as Texas. There and to the east, conditions are expected to bring more severe thunderstorms, damaging winds, and heavy rain.

Freezing rain could pose a threat to parts of the Southern Plains, Lower Mississippi Valley, and Tennessee Valley on Sunday evening through Monday evening, the NWS said, and there is a chance of freezing rain, sleet, and snow along the storm front for eastern Texas, Arkansas, and Louisiana from Sunday to Monday, as temperatures are expected to dive to well below freezing.

Snow squalls are possible on Sunday across portions of the Northeast and the northern Mid-Atlantic. The New Jersey Office of Emergency Management warned in an update on X late Saturday night that snow squall whiteout conditions were possible Sunday morning into the afternoon.

Coastal flood warnings remained in place in Boston on Saturday, after downpours from back-to-back storms saw rivers swell and break their banks. Strong winds in the storm worsened coastal flooding.

Showers and thunderstorms will develop over the Florida Peninsula from Sunday into Monday.

Flight Delays and Power Outages

Many flights were delayed or canceled on the weekend amid the ongoing winter storms, with Chicago O’Hare Airport and Denver International Airport having the most flights impacted.

There were thousands of power outages already across the country on Saturday night, after outages on Friday tracked a storm front as it moved west.

On Saturday, the most widespread outages were reported in Michigan, followed by Wisconsin where snowfall topped 10 inches on Friday. Further east, outages were also seen in Vermont and New Hampshire. By Saturday afternoon, Oregon joined Michigan in reporting significant outages along its coastline.

Texas’s power grid and the state’s independent grid operator, ERCOT, is monitoring for increased power demand as the cold conditions arrive. A historic cold from a storm in February 2021 killed more than 200 people who suffered hypothermia during the resulting power outages that were implemented to prevent a collapse of the power grid. Conditions are not expected to be as severe or prolonged as the 2021 storm.

Forecasted El Niño conditions usually bring heavier snow to parts of the country in winter and see a strengthening of Northeast snowstorms. Under El Niño, winters are usually cooler and wetter in the south, and warmer and drier in the north.

Iowa Caucus to Battle Cold Snap

The cold weather blast is of concern for the GOP’s Iowa Monday evening caucuses, where temperatures are forecast to drop to -5 to -10 degrees F in Des Moines, with wind chill forecast to make conditions feel like -16 to -27 degrees F—the lowest on record for the city on caucus day. The state has held caucuses in January or February every four years since 1972. On average, it’s been the coldest January in five years.

Bad weather on Friday saw most candidates cancel their campaign events, but they reshuffled to accommodate for the bad weather on Saturday. GOP frontrunner former President Donald Trump promised he would fly into the state on Saturday night despite the poor conditions.

The blistering cold could impact voter turnout at the polls.

Over the last week, many areas of Iowa saw storms dump 20 inches of snow, particularly in the east.