Forget spring: This week, much of the interior U.S. gets a taste of summer.
A wave of unusually high temperatures — often 30 to 40 degrees above average — is blasting states from Texas to the Dakotas and east to the shores of the Great Lakes.
That heat follows the hottest December on record, and could also push February into the top spot — a dynamic that portends a hotter summer to come, pushing several heartlands of U.S. agriculture into a newly precarious state.
Much of America “had a two-week winter,” said Brad Rippey, a meteorologist with the U.S. Department of Agriculture. Across the country, trees and crops like oats and winter wheat are sprouting above ground two weeks earlier — putting them at risk when unusual heat gives way to deadly cold, as in the disastrous springs of 2007 and 2017.
According to the National Phenology Network, spring arrived up to two weeks earlier this year than the 20-year average, from five days earlier in Portland, Oregon to 13 days earlier in Virginia Beach, Virginia.
That doesn’t mean the entire continent is warm, or even that the phenomenon of a warm front in late February is unusual.
It’s normal for cold temperatures in the Northwest to push a mass of hot air through the center of the country this time of year, said Joe Wegman, a meteorologist at NOAA’s Weather Prediction Center.
And Cold temperatures in Canada, Alaska and the Pacific Northwest are “terribly widespread,” said Judah Cohen, who leads the seasonal forecasting practice at Verisk AER, which does make forecasts for federal agencies such as the National Oceanic and Atmospheric Administration (NOAA) and NASA.
There’s also the fact that the Pacific Ocean is in the El Niño pattern – which pushes warm Pacific air through the interior of the US, as opposed to the frigid Arctic air that dominates during the La Niña, Scott Handel and Anthony Artusa of NOAA’s Long-Range Climate Prediction Center told The Hill.
But because the planetary heating comes on top of natural weather fluctuations, “the warm parts aren’t a little bit above normal,” Cohen said. “They can easily reach record heat because there’s just so much heat in the system.”
This leads to a risk of “weather whiplash,” Cohen said, where the weather becomes “like a windshield wiper: ping-ponging back and forth from one extreme to the other.”
Right now, that ping pong ball is on the hot side of the table. Federal meteorologists expect more than 70 daily records to be broken on Tuesday. The impending heat is notable in many places, both because of the temperature that will be higher than previous records – often as much as 5-10 degrees above previous abnormal heat waves – and how long many of the soon-to-occur records have held.
In eastern Nebraska, for example, NOAA expects temperatures on Tuesday to break six degrees from the previous record set in February — a standard dating back to 1826, nearly two centuries ago.
That case is a bit of an outlier, he said Wegman of NOAA. Typically, he said, records drop “by 1 to 2 degrees, but we are seeing records that have been in place for more than 100 years being broken.”
In Texas, that looks like a high in the 90s — about 30 degrees above normal. In Iowa and eastern Nebraska, where the anomaly is most pronounced (and average seasonal temperatures are much lower), this means high temperatures up to 40 degrees above average.
Many of the states hit by unusual heat are in the heartlands of key U.S. crops, from blueberries and peaches to oats and wheat.
For most of these regions, early heat “shouldn’t be a problem,” the USDA’s Rippey told The Hill. While he said it’s “not ideal” — many crops are adapted to a particular mix of heat and steadily increasing daylight hours that this heat anomaly can bring — as long as temperatures remain above normal, it would only be an early must mean harvest.
But the early emergence of fruit trees and the early emergence of row crops such as oats, corn, soybeans and wheat also mean that these plants are particularly vulnerable to another kind of anomaly: a late spring freeze that kills young plants that are still growing in normal years. always nests safely in the ground, or freezes the leaves of orchards that are normally still dormant.
The worst example of this was the frost in early April 2007, which followed a record warm March. That spring, temperatures below 70 degrees and high winds destroyed delicate seeds, trees and saplings — leading to an economic disaster that won the grim honor of a spot on NOAA’s list of billion-dollar disasters, a first-ever distinction for a spring shutdown. A similar disaster occurred in 2017, when a mid-March freeze followed an unusually warm February.
While it’s impossible to make predictions beyond two weeks, the risk of this type of “weather whiplash” is increasing, Cohen said.
That’s due to a complex combination: warmer oceans – an increasingly charged thermal battery, now dumping higher levels of heat back into the atmosphere in the cold months; and a weakening polar vortex, allowing arctic cold to escape.
This week’s data demonstrates the first part of that system: normal seasonal patterns of late winter warming “are heading straight for record warmth.” Because there is so much more heat in the air and sea in general, “you start at a higher rung on the ladder — getting to the top is just easier,” he said.
Cohen added that while “some people may find what I just said controversial, it is the least controversial thing I have ever said in my life.”
Less intuitive is the relationship between rising global temperatures and the outbreak of the March cold. Cohen explains the risk of late-season frostbite with the image of two figure skaters spinning in tight circles on the ice with their arms folded — an analogy for the high winds of the polar vortex that keep the polar cold above the North Pole. .
But more heat in the Southern Ocean means a windier jet stream, which “looks like one of those figure skaters putting a crack in the ice.” As the skater stumbles, his arms swing out behind him – “and it’s the same with the polar vortex. When they are hit by the energy coming from the jet stream below, their circulation slows down and you get more outbreaks.”
In effect, this blurs the once-clean distinction between a frigid North and a mild South — a dynamic Cohen described in a 2021 Hill op-ed.
For crops, he added, “the risk is a freeze: they have a ‘false spring’ when it’s unusually warm, things start to bloom – and then they go below freezing and the crop is damaged.”
That’s a particular concern for the Southeast’s blueberries and peaches, as well as “vulnerable” oats and winter wheat, he said.
The unusual temperatures also risk worsening the drought. As part of photosynthesis, plants break down water from the soil to build the starches and sugars that make up their bodies – and ultimately our food.
As crops use soil moisture “earlier and earlier,” this puts crops at risk of depletion – especially in the key corn and soybean growing areas of the upper Midwest, where a “snow drought” has led to below-average water levels seeping into the soil. the ground, Rippey said. As plants struggle upward in an already depleted area, those areas “could run out of moisture if there isn’t enough rain,” he added.
This year’s weather offers some serious comfort over previous years: the drought that has gripped much of the US has largely abated, and a water-stressed part of the Midwest is one of the few significant areas where it sticks around. Just over a quarter of U.S. corn and soybean growing areas are currently in drought, while only 12 percent of winter wheat is in drought.
But that good news only lasts as long as the moisture does, and it can be deceptive. Last winter, wet weather led many West Texas cotton farmers to believe it would be a wet year — an assumption that was cruelly shattered, Robbie Minnich of the National Cotton Council told The Hill.
“They thought, you know, okay, ‘the drought is broken, it’s turned around; and so they really put everything into it,” Minnich said. “And then they got to June and it stopped raining and it was 120 degrees.”
Does February’s record heat mean a hot summer is coming?
Looking at the broader trends, Handel and Artusa of the Climate Prediction Center favor “above normal levels for most of the country for the summer as a whole.”
That’s the result of a complex mix of factors, most notably the likely transition from El Niño back to La Nina, which has led to warmer summers on average in the continental US.
But as to how abnormal that heat will be, NOAA scientists say it’s far too early to tell.
“Based on larger planetary patterns, you can see that in a given month – or even several months – it will be warmer than normal,” says Wegman of the Weather Prediction Center.
“But to now say that this means it will be 30 degrees above normal all summer? That is currently outside the domain of science.”
For the latest news, weather, sports and streaming video, visit The Hill.