A barrage of pop-up thunderstorms flooding streets, swamping basements and casting parked cars afloat is adding to one of the soggiest years on record in the Twin Cities and other parts of the state.
What’s more, this decade will likely be one of the wettest in Minnesota over the last century, according to state climatologist Kenny Blumenfeld.
“We’ve had multiple years of being very wet and fewer dry years,” he said. “The wetter conditions are consistent with our understanding of how climate is changing in this region.”
To be clear, it’s not unusual that it’s rained more days than not this month. It is, after all, the peak of Minnesota’s rainy season, he said. The nearly 5 inches of rain that’s fallen so far this month has landed the Twin Cities in ninth place for the wettest July, according to the National Weather Service.
“Absolutely, it’s wet,” Blumenfeld said. “But it’s been a wet year, and the July rain just adds to that.”
All this water comes on top of a snowy winter that pushed its way into spring, chalking up 66.1 inches of snow compared with the usual 32.6 inches.
“We got into a pretty stormy pattern at the end of January, and it was a pattern that continued right through into May in some areas,” Blumenfeld said. “That’s what set us up for being so wet this year.”
Most of the areas from the Twin Cities to the southern border have landed in the top five wettest years on record to date, he said.
“It’s not in people’s imaginations. We’re trending wetter,” said Twin Cities meteorologist Paul Douglas.
In the 1950s, 26 inches of annual precipitation was normal in the Twin Cities, he said. Now it’s closer to 32 inches, he added.
With global temperatures rising, it’s just basic physics that it’s getting wetter. Warmer air can hold more water vapor, Douglas explained.
“There’s just more water floating overhead, and that water can come down fast,” he said. “That’s what happened the last couple days when these storms stalled and drop 2 to 3 inches of rain in an hour or two. It’s crazy.”
The average monthly rainfall for July is about 4 inches, and some places were hit with that much in an hour or two, Douglas said. When it comes down that hard and that quickly, most of the water runs off rather than soaks into the ground.
“Our infrastructure in Minnesota is not equipped to handle these new supersized rainfall events,” Douglas said. “This is what you would expect in Miami or Manila, not so much in Minneapolis-St. Paul.”
All the water has made it a challenge for farmers to plant and construction businesses to get work done, he said. “It’s a challenge for many businesses to get the same results, to be profitable, to be successful with all this wet, volatile weather. It’s just one more monkey wrench that people have to work through.”
Eventually, it may mean people will have to adapt. “Every business will have to figure out how to create products and services that make us more resilient no matter what Mother Nature throws at us — more flood-resistant, more drought-proof, more storm-tolerant,” Douglas said.
But for now, the late-afternoon storms pounding parts of Minnesota are fairly normal for this time of year.
“In Minnesota, that’s how storms have behaved for decades, if not centuries,” Blumenfeld said. “It’s the part of the day when the most heat has accumulated to grow a thunderstorm.”
And because the winds aloft are weak, the storms can be more isolated, soaking some areas while others stay dry, he said.
But for all those who feel like they’ve been under a rain cloud all summer, rest assured, blue skies will return.
“The next 10 days look fairly dry,” said Caleb Grunzke, meteorologist with the National Weather Service in Chanhassen. After that, the rest of the month may be drier than normal, he added.
That doesn’t mean the rainy season will end. According to Blumenfeld, more consistent drier weather doesn’t usually happen until September or October. “It wouldn’t be unusual if we dried out in August,” he said. “But it also wouldn’t be unusual if we remained pretty wet until astronomical fall begins and the spigot is turned off.”