REGIONAL- Forecasters predict a wet weekend here in the North Country, but it likely won’t be wet enough to ease the ongoing drought conditions in the region, which have persisted since last fall. While the border region is considered abnormally dry, at least 80 percent of St. Louis and Lake counties are currently in moderate drought, according to the U.S. Drought Monitor. A large portion of north central Minnesota, including a small portion of western St. Louis County, is considered to be in severe drought.
“We have been dealing with drought basically since late last summer,” said Ketzel Levens, a National Weather Service meteorologist in Duluth. “We’ve gotten enough precipitation that things haven’t gotten worse, but we haven’t gotten enough precipitation to actually see improvements in that drought.”
Weather reporting stations across northern St. Louis County were all reporting less than two inches of precipitation so far this year as of the Timberjay’s Wednesday press time. Precipitation is running anywhere from 40 percent below average in Orr to 12 percent below average in Tower.
The continuing dry weather has left limited snowpack on the region’s landscape and that snowpack diminished even further with the near-record high temperatures seen in the region this past Sunday and Monday. That could well mean the spring fire season will start earlier than usual again this year. Indeed, parts of southern and west-central Minnesota were already subject to red flag warnings earlier in the week due to high fire danger from warm temperatures, low humidity, and high winds.
Flood risk minimal
Given the current conditions, it’s no surprise that the National Weather Service is predicting a low risk of spring flooding this year. Matt deWolfe, with the Lake of the Woods Control Board, cited data from the Midwest Regional Climate Center’s Winter Severity Index which shows that this winter has indeed been mild, which bodes well for limiting flooding.
“It’s basically a formula to try to measure how bad the winter has been,” deWolfe said. “We’re technically in the mild, just below the moderate, zone. High water years tend to have a more severe winter leading into spring, and we are well below where those winters were at this time of the year. We obviously don’t know what’s coming next for the next month or two, but I think this is a good indicator that compared to those years, we’re in a better position in terms of the winter conditions.”
Water flows into the Rainy Basin are running from the bottom range of normal to well below normal, deWolfe said, measures consistent with the ongoing drought conditions.
Computer simulations using the available data show a less than ten percent chance of minor flooding for three rivers in the basin. The Kawishiwi near Ely has an eight percent chance of minor flooding, the Vermilion River at Crane Lake has a seven percent chance, and the Little Fork at Littlefork has less than a five percent chance. The chance for moderate flooding for all three is less than five percent.
One wild card in the flood equation is an unusually deep layer of frost in the soil. While there are few direct measurements available, Levens pointed to the 30-inch frost depth at the NWS Duluth office, 12 inches deeper than average, as an example of the severity of the frost. The frost depth at Big Sandy Lake is 48 inches, more than two feet deeper than average.
“We’ve had some very cold temperatures through January and early February, which has allowed us to put a lot of frost in the ground on the U.S. side,” Levens said. “The soil temperatures themselves are interesting – they’re not the coldest we’ve ever seen, suggesting that if we got some warm temperatures they would start to thaw out. But there’s a lot of soil to thaw out, and this could lead to really poor infiltration, meaning that instead of acting like soil, the soil acts more like asphalt and water would just run off. That can happen either with snow melting or if we were to get a rain on frozen ground event.”
The other unknown factor is rain, and the three-month forecast holds little in the way of clues, as it predicts equal chances of below average, normal, and above average precipitation.
“We’ll likely continue to see that rain is going to play a really big factor,” Levens said. “If we get any heavy rains on top of melting snow, that would be a concern, especially with how frozen our ground currently is. That frost depth, again, is probably one of the most likely places where we have that uncertainty with spring flooding.”
David Colburn contributed reporting for this story.