- NOAA predicts impactful El Niño effects this winter, pushing Michigan toward a milder, drier season.
- Greater variability in weather is also predicted, with negative effects on certain native wildlife and agriculture.
- Polar vortex disruptions and lake effects may bring an added layer of variability.
Jonathan Overpeck, University of Michigan professor and Dean of the School of Environment and Sustainability, spent a formative part of his childhood in Michigan.
“You know, we'd build a snow fort in December, and it would still be there in February. And now, you know, we get these warm temperatures, and the snow fort will be gone. But then it'll get cold again," he said. "So we can get subzero weather even though we're getting warmer temperatures. But it'll just be more variable.”
According to the National Oceanic and Atmospheric Administration (NOAA), a massive El Niño is already affecting the Great Lakes region. The warm and cozy fall broke records in parts of Michigan this year, and the winter weather has barely started.
The hugely impactful climate pattern, coupled with polar vortex disruptions, is likely to fundamentally shape this winter and the year to come. In Michigan, the effects could be both positive and negative and could be a big player in wildlife survival and agricultural success.
What is El Niño?
“Of course, many people always ask, ‘Well, what is something thousands of miles away from the Great Lakes? What does that have to do with us?’ And the answer is that these events are so large and involve just thousands of square miles of ocean that they basically influence the flow of the jet stream in both hemispheres, both the North and the South. And of course, the jet stream is what controls our day-to-day and week-to-week weather patterns here,” explained Jeff Andresen, state climatologist and professor at Michigan State University.
El Niño is a part of a periodic and natural cycle of weather patterns that drag across the globe every few years. It has to do with the shape and physics of living on a sphere made mostly of water, traveling around the sun and being unevenly heated.
“This is one way that the climate system attempts to rebalance itself, and (as) it overheats in certain areas, it cools off too much in others,” said Andresen.
Julia Cole, professor at the University of Michigan, explained the science and geography behind the phenomenon. She said that the equatorial Pacific is warming. The water warms the air over it. It then rises all the way up in the atmosphere, and starts to change the normal air flow that occurs around the globe.
“It's like sticking a stick in the river, right? It changes the flow downstream. It changes the flow of the upper atmosphere that connects the tropics and the extratropics,” said Cole. It shifts the polar jet stream north, allowing for warmer conditions farther north as well. ”What's happening in the Pacific is able to affect the global climate and climate variability as far away as Michigan, mainly by changing the way the atmosphere circulates.”
Climate change is basically supercharging it on one end, adding heat and energy to the system, creating more extreme and unpredictable patterns.
Cole’s research on this was recently published in Science magazine. It used modern and fossil coral records to reconstruct historic sea surface temperatures. Her team found an unprecedented increase in variability, particularly over the last 40 years.
“It's amazing to think that these corals growing in the tropical Pacific are responding to some of the same rhythms that we here in Michigan might be feeling,” said Cole.
Wildlife and agriculture impacts
One of the predictions is that we will have increased variability. Which can mean what’s called winter “heat waves.”
This can be hard on hibernating animals, especially pollinators and other insects that need a hard, cold winter or insulating snowpack. For some, the snowpack helps them stay warm; for others, like the woolly bear caterpillar that freezes solid all winter, there’s a cost to warming up and then having to freeze again. It could also allow invasive tropical organisms that would die off during a hard winter to survive.
According to Yash Sondhi, an entomologist from Case Western Reserve University in Ohio, it can also cause some insects to “wake up” too early, leaving them without the proper resources in an early spring. If the plants haven’t fully grown out yet, but the insects are looking for food, they can starve.
“ El Niño years mess up everything, but a lot of it is because they mess up the plant cycle, so then the animals just don't have anything to eat, so they emerge and they're just starving… So it does affect their population, but the assumption is that they can recover in the next year or two,” said Sondhi. “They have lots of natural fluctuations, but El Niño years the numbers really drastically fluctuate more than in non-El Niño years.”
The variability also makes it hard to plan for agriculture, as it changes growing seasons and threatens plants with unusual cold snaps and mini heat waves.
“ The variability, especially the occurrence of extremes, it's almost more challenging to manage or to deal with than these changes in mean. Humans for a long, long time have been able to deal with changes, in trends that are orderly. But when you change the extreme events or you change the variability, it's much, much more complicated. And that unfortunately is also a piece of what we're seeing currently in our part of the world.” said Andresen.
It’s not all bad news, he explained.
“If it is a mild winter, we tend to see an earlier start of the growing season. And for some elements of agriculture, that's not such a bad thing,” said Andresen. More growing time and more options for field work can be a positive result, he explained. But for some crops that overwinter, like Michigan’s famous fruit orchards, an early end to winter or increased temperature fluctuations have the potential to cause cold injuries on the plants.
It’s complicated
Despite a lot of talk of warmer weather and polar jet streams pushed north, there is also a polar vortex disruption to contend with. And this week may not be the only wild card of the season; experts are watching for continued disruption later this month.
And then, finally, lake effect will have complicating effects as well. A warmer winter could mean less lake ice cover, which could mean more lake effect snow. So the map of future weather predictions is currently a mosaic of impacts.
Overpeck explained it best when he advised me to get some good coats, “ I love cold weather. Nothing beats sitting at a football game when it's below freezing, you know, and your feet are going numb.”
