111 days of snow cover: Long winter ranks third in history

By one metric — the number of consecutive days with 1 inch or more of snow on the ground in Missoula — it's the third-longest winter on record. And records for that measurement go back to 1893. 

"We had 111 days where we recorded a snow depth of 1 inch or greater, from Nov. 10 through Feb. 28," according to Bob Nester, the senior meteorologist at the National Weather Service's Missoula Forecast Office. "That ranks third — third longest since 1893."

This winter's third-place streak ended Feb. 28 when "we went down from an inch to just a trace on the ground," he said. The official measurement is taken from the NWS office at Missoula International Airport. Nester noted that other areas of Missoula — the South Hills, for example — often see more snow accumulation and lingering snow cover. 

The all-time record for consecutive days with 1 inch or more snow at the NWS Missoula office is 122 days, set in the epic winter of 1996–97. The second longest stretch recorded was 115 days, in 1978–79. 

"Last year we had, well there was one that we had 18 days, and it must’ve melted, and we had 68 days" from mid-December to mid-February, he said. "This year, it just happened not to melt." 

But Missoulians don't need to know the statistics to feel that this winter — well, it just feels "long and cold," according to Tyler Clark. Clark, a lifelong Missoulian, is the excavation manager with Montana Excavation Services. No matter the conditions, he's often working outside with earthmoving equipment. But this winter, that often also means snow moving. 

"Been frustrating, things take a lot longer," he said Friday. "We are pretty lucky because we have access to our own personal ground-thaw unit. But it’s definitely been frustrating. It’s harder on equipment too. Burns more fuel, not quite as efficient. We’re looking forward to spring." 

But, he added, "As hard as winter has been, it takes more than cold to stop us." 

Clark, in his mid-30s, said that this winter stands out: "It feels like it’s been five months long. It started in the first week of November and it hasn’t really let up that much. Just when we think we’re getting some sun, it hammers us again. It’s pretty hard, it melts everything and freezes right away, and it makes a mess." 

Some winters in Missoula, Clark said, there's hardly been any snow when Christmas rolls around. In fact, NWS records show that in 1954, it took until Dec. 26 to measure 1 inch of snow in Missoula — the latest ever. Clark wasn't around then, but despite being only a few years old in 1996, he remembers it as a monumental winter for snow. 

This year, in contrast, is pretty average in terms of snowfall, according to Nester and data from weather stations in the area. In the mountains around Missoula, snow depth was anywhere from 80–100% of normal on Friday. Snow-water equivalent, or the amount of water in the snowpack, was in the same range.

So, with a fairly normal winter in terms of snowfall, what's made this one so long?

"We didn’t really have a lot of really warm days," Nester said. "This year’s average temperature was 24.8 degrees for Nov. 1 through March 9," which was the 15th coolest in the past 75 years, or in the top 20% of coldest winters. 

"Seems like it’s been a long winter just because we had snow on the ground most the year, even though it’s been relatively low," he said. "It’s just been kind of a long winter because we haven’t had any real warms spells over the winter to give us any hope." 

The Nov. 10 start to this winter's streak of snow cover was also the first day this winter that NWS measured 1 inch or more of snow in Missoula. On average, there isn't measurable snow cover in Missoula until Nov. 16, according to NWS records dating to 1947. Since then, the earliest Missoula has recorded 1 inch or more of snow was Oct. 7, in 1985. 

"The winter seemed longer because it started earlier," Nester said, noting that the key this winter was the Nov. 10 snow sticking around until the end of February. 

But the pattern is breaking. Despite yet another in a series of atmospheric rivers of moisture clobbering California with record rain and snow — and a weekend storm that buried southern Idaho and coated western Montana's mountains — this winter's La Nina pattern has broken. 

"Third season in a row we’re under La Nina conditions," Nester observed. "That La Nina officially ended here in the last week, (according to) our climate prediction center. We’re going into more neutral conditions." 

That development tracks with predictions the center issued in the fall, which foresaw an early start to winter, a cold and snowy winter with ongoing La Nina effect, and a rebound to drier conditions with the end of La Nina in late winter or early spring. 

But despite the chance of respite from winter on the horizon, the winter that seemingly began Nov. 10 is one for the record books — if only in third place. 

"I’ve been here 23 years," Nester said, "and it’s felt like one of the longer seasons."