The United States is a divided nation, with a frigid climate of snow and ice from east of the Rocky Mountains to Florida, and record warmth and light snowfall in the West.
That dichotomy has been going on for weeks, and it’s finally about to change after another big blast of arctic air into the East this weekend.
This gap has become even more acute in recent days. While parts of the West are experiencing late spring-like warmth with temperatures 20 to 30 degrees Fahrenheit above average, parts of the East are expected to experience their coldest temperatures so far this season this weekend.
For example, Great Falls, Montana is in the warm category. Residents are forecasting five consecutive days this week with highs above 60 degrees Fahrenheit, which will be the hottest five days in a row for February on record.
And in Los Angeles, temperatures reached a record high of 88 degrees on Wednesday, exceeding typical highs for July and August.
It is worth noting that the pattern of cold in the east and warm in the west is caused by distortions in the jet stream, and is so pronounced and persistent. Washington, D.C., for example, had the sixth longest consecutive period of below-freezing temperatures, from January 24 to February 2. Similar times were recorded in many other cities, making it one of the top 20 longest times of all time.
Warmth and less snow in the West have been the hallmarks of this winter so far, predating the colder weather in the East. But what’s so striking about weather maps is the contrast in temperature that divides the country.
At one point last weekend, Juneau, Alaska was warmer than central Florida.
Warm, dry conditions in the West can be traced to a persistent bulge, or ridge, in the jet stream that diverted storms and cold air northward. But downstream, large depressions, or troughs, in the jet stream are digging in, bringing wave after wave of arctic air south, creating ideal conditions for powerful winter storms to form.
Many places in the Carolinas and even Atlanta received more snow during January than Salt Lake City. The drop for the month was just one-tenth of an inch, well below the average of 12.7 inches.
For those still shivering in the East and tired of warm, dry conditions in the West, a change in pattern is finally in sight.
The western ridge is predicted to break, which will set the pattern in motion, paving the way for milder air to move east and eventually for some of the Pacific storm system to move west.
But before that happens, the coldest air of the winter so far will invade the Northeast and Mid-Atlantic states this weekend and early next week. About 50 low temperature records could be set this weekend, with temperatures in the single digits but feeling like double digits below freezing.
Because winter is the warmest season in the United States, there are few cold records, especially monthly and all-time coldest records. This is reflected in data that compares daily warmth and cold records over the past few days with the entire year.
During the peak of the Arctic blast in the last week of January and early February, cold records outnumbered warm records by more than 2 to 1 in the Lower 48 states. However, looking at 2026 so far, this is not the case; the number of warm records since January 1st is about 1.5 times the number of cold records.
In a rapidly warming world, warmer temperature records are increasingly outpacing colder ones.
So why is it so cold in the east? Forecasters believe the Arctic Oscillation, a broad upper-level pattern that manifests in pressure differences between the North Pole and mid-latitudes, is partly to blame.
“One factor likely to be playing a role is the Arctic Oscillation (AO), which characterizes how undulating the jet stream is,” said Laura Siersto, an atmospheric scientist at the NOAA Climate Prediction Center.
“The AO has remained negative for over a month now, which is surprising because it doesn’t normally stay in one phase for this long, so something else could be at play that is keeping it in the negative phase,” he said, noting that events elsewhere, particularly in the tropical Pacific, have also played a role in influencing North America’s recent weather patterns.
CNN meteorologist Brandon Miller contributed reporting.
