If you’re looking for good news in this weather story, you might want to start to read something different. May we suggest something about the outdoors or political commentary?
Because forecasters with the National Weather Service and climate scientists say that while July has been exceptionally hot, dry and smoky — in Montana, it’s not likely to change until as late as November.
Previously, this year — before summer hit the state like someone turning on lights — forecasters had predicted an average, maybe slightly above average summer. Computer models didn’t indicate much out of the ordinary.
But John Wetenkamp, science and operations officer with the National Weather Service in Billings, said that computer models have a hard time predicting unusual weather events, like the high-pressure ridges, commonly referred to as “heat domes,” that keep temperatures hot and dry for extended periods. And those same models don’t anticipate the cumulative effects of what happens with the heat domes as they pile up, or well, snowball.
Instead, the most up-to-date forecast for the 2021 summer issued on Monday is a parade of interrelated bad news that may affect everything from how we breathe to how fish and forests may die.
Part of this hot and dry summer began before summer, Wetenkamp said, as May and June were among the driest in recorded history. May and June are typically the wettest time of the year for the region, according to NWS data.
With snowpack literally evaporating and melting quickly, the ground became parched and water reserves were running low. June and July continued to be hot without much more than an isolated shower here and there. Wetenkamp explained that as the ground itself dries out, it makes it more likely for increased temperatures. The sun bakes the ground, which, in turn, loses part of its ability to absorb the heat and reflects it back into the atmosphere, causing temperatures to rise.
Meanwhile, heat domes are pockets of high-temperature air that create ridges, almost like fences that lock in the extremely hot air. Wetenkamp explained that most of the time in Montana, those high-pressure heat patterns last a day or two but are often broken up by storms or other weather systems. However, with the extremely high pressure ridges, or heat domes, they are more stubborn and not as easily broken up. Because of that, heat stays longer, which dries out the land more, which leads to warmer temperatures in a sort of heat feedback loop that has seen temperatures soar into the triple digits and hold there for weeks.
The hot, dry temperatures have also increased the likelihood of forest fires, which are helped by these conditions and often mitigated by breaks of cool air or even moisture. However, with little cool-down in site, the NWS predicts the hot and dry lasting through August, September and maybe into October. The smoke cover lessens the temperatures by a degree or two without the direct sunlight, but that’s literally little comfort when temperatures soar into triple digits.
The weather ripple throughout Montana’s economy is likely to be felt in a number of significant ways. The extended forecast predicts that “agriculture and ranch will continue to be stressed by hot dry conditions,” and that tourism and outdoor recreation will be hampered by periods of intense heat and health-related illnesses caused by smoke.
In fact, the smoke cover Monday in Montana was so extreme and widespread the Department of Environmental Quality could not pinpoint which Western forest fires were to blame for the blanket of gray smoky haze that covered the state.
Beyond the immediate impacts of the weather this year, climate scientists are noting an extreme and dangerous pattern that could extend well beyond 2021. The National Weather Service tracked temperatures in Billings through the first two weeks of July, where the average high was 92.4 degrees, compared to the normal of 85.2. That’s consistent with reporting by The New York Times which showed Billings, Denver, Boise and Salt Lake City during the course of the past 50 years. Billings’ average temperature climbed from 87 in 1970 to 89 degrees currently, while Boise jumped from 91 to 94.
Climate scientists have said there’s virtually no chance the weather would reach into the triple digits across much of the country, including in traditionally cooler spots like Seattle or Portland, without climate change.
“These are becoming more common,” Wetenkamp said.
A graphic produced as part of the NWS’ weather forecast also shows that nearly the entire state has received 50 percent or less normal precipitation from the end of June through Monday. During the same time, most of the state was six to eight degrees warmer than the normal temperature. All of that means temperatures will stay hotter for longer, and it decreases the chance of precipitation to break the cycle.
“You just build heat where it seems to reinforce itself with hotter days and dry land,” Wetenkamp said. “To see (the high temperatures) set up that early and last this long? That’s rare.”