Minnesota's Longest Winter
Apr 19, 2018 11:36AM
Editor’s note: Two weeks ago, we reported that the record for continuous snow cover was 172 days, set in Duluth in the mid-1950s. That was the longest stretch that State Climatologist Pete Boulay could readily find on digitally-available records, and it was a record that most weather stations in northern St. Louis County surpassed as of Tuesday. But our inquiry prompted Boulay to dig deeper, through the dusty old paper records at the state climatology office, which is where he found the data documenting an even more impressive winter at the former Pigeon River border crossing at the tip of the Arrowhead. The story below reports on his findings.
REGIONAL— Here’s a record that most North Country residents would probably rather not break. Back in the cold and very snowy spring of 1950, the weather station at the Pigeon River crossing at the Minnesota-Ontario border recorded continuous snow cover for a total of 190 days, the longest such period ever officially recorded in the state. It was a remarkable winter in the region, with exceptional snowfall and record late ice-outs just about everywhere.
History buffs will likely remember that Lake Vermilion’s latest-ever ice-out, for example, was set on May 23, in the spring of 1950.
At Pigeon River that year, the local weather observer recorded a state record of 170.5 inches of snowfall during the winter of 1949-50. On March 28, 1950, the observer reported a total of 75 inches of snow on the ground, the greatest average snow depth ever reported in Minnesota. April didn’t bring much relief, as the station picked up 31.5 inches of new snow during the period and began the month of May with a solid 30 inches of snow still on the ground. The snow cover increased to 35 inches three days later, when the Pigeon River station picked up another six inches of snow on May 3.
Weather observers in northern St. Louis County probably won’t beat any of those records, but they likely won’t miss the continuous snow cover record by much. As of Friday, the region will have reached 176 days of continuous snow cover, which is defined as having an average of at least one inch of snow cover on the ground.
But unlike that winter at Pigeon River, the persistent snow cover in northern St. Louis County has been much more a function of persistent cold than abundant snowfall. In fact, barring any other major spring snowstorms, the winter of 2017-18 will enter the history books as decidedly average for snowfall. As of this week, snow totals across northern St. Louis County ranged from 70 inches in Tower to 84 inches near Cook, very close to the long-term average of 71 inches (in Ely).
This year’s lengthy stretch of continuous snow cover benefitted from an early start. A two-inch snowfall across much of the area on Oct. 27 marked the start of the snow season north of the Laurentian Divide. A little more snow the following day, three inches on Halloween, and back-to-back snows of several inches the first week of November left more than a foot of snow on the ground in much of the region.
While milder conditions later in the month and early December melted some of that snow, weather observers in the area reported that the snow never left entirely. “We’ve had snow on the ground since Oct. 27,” notes Don Potter, who reports the weather from his home outside of Cook. “We didn’t have any gaps at all,” he added.
Roland Fowler, in Embarrass, confirms the same. “The snow came early and it never left,” he said.
That’s a contrast to the winter at Pigeon River, when the snow cover arrived for the season on Nov. 12, a far more typical date in northeastern Minnesota. It was a cold and snowy April, and that final snowstorm in May, that clinched the record for Pigeon River. The last inch of snow on the ground disappeared there that year on May 21.
It’s worth noting that the former crossing at Pigeon River was located well inland from the current crossing, which meant it wasn’t as subject to the warming influences from Lake Superior. That, undoubtedly, contributed to the lengthy period of snow cover recorded at the station there.
Snow cover can be tough to measure at times, notes State Climatologist Pete Boulay, particularly in forested regions, like northeastern Minnesota, where snow depths can vary quite a bit depending on a number of factors. It can be a bit of a judgment call at times, best determined by averaging several readings.
As of Tuesday, April 17, snow depth mapping completed daily by the National Oceanic and Atmospheric Administration showed snow depths in northern St. Louis County ranging from 16-30 inches.
To beat the Pigeon River record, that remaining snow will need to linger until May 5. With no dramatic warmup in the offing, the North Country could well give that record a run for its money. But is that really a record we want to beat?