Spring weather, meteorologists said, can be volatile when cold and warm air collide—but they described Monday’s U.S. forecast as unusually broad in what it combined and how abruptly it shifted. They pointed to an often-springtime setup in which the jet stream swings north and south, helping different regions experience different hazards at roughly the same time. AccuWeather meteorologist and vice president of forecast operations Dan DePodwin said the country was seeing “most types of extreme weather across the U.S. here in mid-March,” and he said those extremes can happen during spring’s clashes of air masses.
DePodwin said, though, that it is “unusual for everything to be at the absolute extreme levels that they’re experiencing right now, but it is not completely unusual in spring to see wild weather happen.” Climate Central Chief Meteorologist Bernadette Woods Placky also said spring can bring sharp swings, calling it “unusual for everything to be at the absolute extreme levels,” while adding that “it is not completely unusual in spring to see wild weather happen.” She said the Southwest’s emerging March heat dome was the notable exception, expected to push temperatures toward “record-shattering” levels and conditions that resemble June more than March.
As the day unfolded, multiple kinds of hazards were active at once, forecasters said. Around the Great Lakes, a blizzard dumped snow “by the feet,” while damaging high winds started marching across the Eastern part of the country, with some areas facing threats of tornadoes. After those storms and cold-weather impacts began, experts said Arctic cold followed, adding to the contrast across regions in the same time window. Meteorologists said their maps reflected that broad range of dangers, with one depiction described by Yale Climate Connections meteorologist Jeff Masters as so visually varied that “This might go on the wall of an art museum; it’s pretty colorful.”
Meteorologists said spring’s weather pattern is not only about temperature swings but also about what the jet stream does to wind and moisture. DePodwin said the jet stream’s changing track creates a setup where strong winds build and where springtime moisture can combine with those winds to trigger severe storms. He said the timing is often February, March or early April, when the jet stream is moving into its more northerly route and drawing warmer air northward, increasing clashes between air masses. At the same time, he said it can still be cold enough that “winter storms can hit like they did in the Great Lakes.”
Scientists also said Monday’s “doozy” pattern fit a springtime mechanism while still showing what they described as possible climate-change fingerprints. Jennifer Francis, a climate scientist at the Woodwell Climate Research Center on Cape Cod, said the situation had a human-caused climate component, saying: “The positions of the enormous northward and southward swings in the jet stream are likely being influenced by the strong ocean heat waves in the northwest Pacific, around Baja, and along the Atlantic seaboard, which are fueled by human-caused climate change.” Francis said March’s extremes can be understood through jet-stream behavior, but she added that the ocean heat waves—linked to human-caused warming—are part of what may help drive those swings.
In the near term, experts said the biggest change coming for many parts of the country was not the storms already occurring but the heat expected soon after. Jeff Masters, Woods Placky, Michael Mann and DePodwin all said the “most unusual” weather was still coming in a day or two, when a strong high pressure or heat dome was expected to park over the Southwest. Masters said Phoenix has only once had a March day reaching 100 degrees, and he said forecasts called for five straight days of triple-digit temperatures “flirting around 107 (41 Celsius) or higher.” Masters and others also discussed a record benchmark: the hottest March day on record in the U.S., they said, was 108 (42.2 Celsius) set in Rio Grande City, Texas, in 1954, and they said there was a chance it could be tied or broken.
They tied that heat risk to broader hazards already present in the drought-stricken West, including wildfire danger. Masters said he worried about fires “like the one blazing in Nebraska at record levels,” and said, “We’re going to see an early and severe fire season out West.” Experts also pointed to the role of unusually warm ocean waters feeding heavy rain systems near Hawaii. Woods Placky said the downpours there were associated with a “Kona low pressure” and that unusually warm Pacific waters were fueling it, adding that some meteorologists view the system as part of the jet-stream wildness.
In the larger context, meteorologists said the overall pattern comes from the atmosphere’s springtime behavior—jet-stream swings, wind, and moisture—but they said climate change can amplify the extremes that result. Woods Placky said climate change fingerprints “are giving it a little extra boost,” though she said that boost would not be as heavy as the “heavy greenhouse gas influence” on the unprecedented heat expected later this week. DePodwin, Placky and others said the day’s events reflected what might happen when jet-stream dynamics produce multiple extremes in the same broad time frame, making Monday’s weather, in their view, the start of an episode that researchers will study as it develops.