NEWS

Why Fort Collins had such a weird winter

Jacy Marmaduke
jmarmaduke@coloradoan.com

As Fort Collins’ winter season ticks off its final days in another burst of sunshine and warmth, something has become quite clear.

We got faked out.

Where was the snow this winter? The chill that inspires lit fireplaces and mugs of steaming cocoa? The red ears tingling from sub-zero temperatures?

We got them, all right – from December to early January, and rarely again after.

Instead, this winter was made of sunny days and highs in the 50s, 60s and even 70s punctuated by the occasional cold snap. We set a handful of heat records. For 42 days from Jan. 1 to March 12 – that’s 60 percent of the time – we had highs in the 50s or warmer.

After a healthy start to the snow season, the flakes just stopped falling after early January. Fort Collins has received about 5 inches of snow since our last big storm in January, and halfway through what’s usually the snowiest month of the year, we have received a trace of snow.

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State climatologist Nolan Doesken calls this our “abbreviated winter.” And while it’s lovely to hike Horsetooth without a jacket in February, the warmth and dryness don’t bode well for regional drought, residential lawns and fruit trees that bud early during warm winters.

Fort Collins has received about 9 inches of precipitation in the last 12 months, compared to a normal amount of about 15 inches, rendering our moisture levels “really painfully low,” Doesken said.

The coming spring, which officially starts Monday, is our best shot at catching up, Doesken said. If spring storms don’t come through, it’s time to start worrying about worsening drought.

So what's to blame for our lack of moisture? Blame it on the jet stream, that meandering wind ribbon that brings Northern Colorado much of its winter cold snaps and snowstorms.

In recent months, the jet stream has wriggled just north of our reach, bringing big snows to Wyoming and leaving Northern Colorado out to dry. South of the jet stream sits a pesky high pressure ridge that keeps conditions warmer and dryer than usual.

You can also blame this winter’s weirdness on climate change, according to Doesken.

“Normal temperatures have definitely risen,” Doesken said. “You’d expect every three to six years you’d have one year that was considerably below the long-term average, and we just haven’t been seeing any years like that.”

Weather data from this season is a bit deceptive because several short-lived cold snaps evened out average temperatures. February’s freak ice storm and early January’s intense cold snap and snowstorm made this winter look more average on paper than it felt for residents.

Oh, and don’t forget all the crazy wind we’ve seen lately. Northern Colorado has been collecting red flag days for weeks, with gusts of wind fueling grass fires and knocking trees into houses and cars.

Doesken argues the winds aren’t so crazy, although Northern Colorado wind data is admittedly sparse.

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Our windiest days often come in February and March, Doesken said, when the jet stream is “howling” above us. In early spring, when the days are lengthening and the sun is bright, warm surface air intermingles with cool air in the jet stream and makes for breezy days.

The timing of our windiest weeks is a little different every year because of the fickle nature of the jet stream and other meteorological phenomena.

This winter has been weird not only for Fort Collins but for much of the country.

California saw a series of heavy storms that brought long-sought relief after years of drought and caused the Oroville Dam spillway to fracture. The East Coast saw an unusually dearth of snow and early start to spring followed by a massive winter storm on Tuesday, prompting a lot of images of frozen cherry blossoms in Washington, D.C.

Back in Northern Colorado, mountain snowpack will probably save us from the worst-case scenario of regional drought paired with tepid water supply. A burst of big snows from mid-November to mid-January amped up mountain snowpack from about half of the average amount to nearly 160 percent of the average by Jan. 12. A recent dry and warm spell for the mountains has eaten into that abundant snowpack level, but we are still above average.

This week should be dry, forecasters say, but March and April are big snow producers for the mountains and now through June are usually Fort Collins’ wettest months. And we will need that moisture to break out of the moderate drought that has a chokehold on the region.

“We’re moving into our normal wetter season from the Front Range eastward,” Doesken said. “Will it arrive before we get more wind and heat? It’s always sort of a wait and see.”

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Fort Collins snow and precipitation, 2016-2017

November: 3 inches snow, 0.43 inches precipitation 

Average: 8.6 inches snow, 0.76 inches precipitation

December: 8.2 inches snow, 0.52 inches precipitation

Average: 8.4 inches snow, 0.5 inches precipitation

January: 11.1 inches snow, 0.89 inches precipitation

Average: 7.9 inches snow, 0.4 inches precipitation

February: 4 inches snow, 0.52 inches precipitation

Average: 6.9 inches snow, 0.4 inches precipitation

March (through March 13): Trace snow, 0.03 inches precipitation

Average (through March 13): 5 inches snow, 0.6 inches precipitation

Total: 26.3 inches snow, 2.39 inches precipitation

Average: 36.8 inches snow, 2.66 inches precipitation