Before looking ahead to the weather factors that may influence snowfall during the 2016-2017 season, let’s look back at where and when the powder fell in Colorado during the 2015-2016 season.

Last season (15-16) featured one of the strongest El Ninos on record, which means that the ocean water temperature in the south-central Pacific Ocean was much warmer than normal.

This abnormally warm water influenced weather patterns across the globe, and in North America, El Nino usually means more snow in the southern areas and less snow in the northern areas. In Colorado specifically, El Nino usually means a tendency for average to above average snow in the southern mountains, near average snow in the central mountains, and average to below average snow in the very northern mountains.

That’s not exactly how things turned out, though. In reality, the northern areas wound up with near normal snowfall while southern areas started strong but finished weak and turned in season totals that underperformed the long-term average.

The red line on the chart below shows how snowpack normally increases each month, peaking in early to mid-April. The thick blue line shows the actual snowpack during the 2015-2016 season, and the other colored lines show the same for other seasons.

This chart covers all of Colorado based on data from 145 government-run backcountry weather stations called SNOTEL.

Snowpack was near average from October through mid-February, went below average in late February and early March, then trended up during late March and April. We never quite got to the average peak, but the late-season storms kept the snowpack in good shape until mid-May’s typical rapid melt out.

 

The SNOTEL network was created to track snowfall for one purpose: Predicting spring and summer water flows on streams and rivers. Thus, when we look at groupings of SNOTEL sites, they are usually grouped into river basins.

Below is a map of the river basins with data about total precipitation between October 1, 2015 and August 12, 2016. The color shading (all green!) means that all river basins have recorded close to average precipitation between these dates, and the white numbers show the exact percentage compared to normal. Use this map as a reference for river basin locations.

 

The next map shows the snowpack specifically in the Yampa and White river basin, which is home to Steamboat. This area is in the northwestern area of Colorado, and typically El Nino translates into somewhat below-average snow. Not so last winter, as the snowpack (blue line) was close to average for the entire season.

The Upper Colorado river basin was also near average during most of the winter. This area is home to most of the I-70 resorts, including Winter Park, Abasin, Keystone, Breckenridge, Copper, Vail, Beaver Creek, Cooper, and Powderhorn.

To the east, along the front range, the South Platte river basin was also near average for most of the season, and many late-season storms in April and May increased the numbers to well above average. This river basin includes the ski areas of Loveland, Eldora, and the Indian Peaks and Rocky Mountain National Park.

 

The central mountains around Aspen also fared well with a near normal snowpack for much of the season, though there was a dry period in February and early March. The graphic below shows the snowpack in the Roaring Fork river basin, which encompasses the Aspen area. The water that results from snowfall in this region eventually flows into the Colorado river.

The Gunnison river basin in central Colorado has the honor of encompassing Crested Butte and some peaks in the northeastern San Juan mountain range. Like the Roaring Fork basin, the Gunnison basin saw average to above average snowfall during the first two-thirds of the season, went dry for much of February and early March, and then benefited from late-season storms in late March and April.

In central-east and southeast Colorado, the Arkansas river basin also had a good start to the season, trailed off in much of February and March, then the snow picked back up in late March, April, and even continued into early May. This region includes Monarch ski area and the Collegiate Peaks of the Sawatch Mountain range near Buena Vista.

 

Up through now, we’ve talked about the northern and central mountains, all of which enjoyed near average snowfall during the season.

When we were going into the season, we were expecting a tendency for above average snow in the southern mountains due to the influence of El Nino. However, that proved to only be half true, limited to the first half of the season.

The next two charts show the snowpack in southern Colorado.

The Upper Rio Grande river basin includes Wolf Creek:

 

And the San Miguel, Dolores, Animas, and San Juan river basins include Telluride, Silverton, and Purgatory.

 

Both of these southern areas enjoyed well above average snowfall through early February, and then the atmosphere’s snow machine stopped cranking out consistent crystals during the rest of the season. This is a good lesson that, despite any historical correlations with El Nino or La Nina, snowfall patterns vary quite a bit, and no historical correlation or trend should be used as an assured predictor of the future.

Thanks so much to our public servants who dreamed up, installed, and maintain the SNOTEL network here in Colorado and throughout the western US. These stations provide consistent data from year-to-year, which is extremely important when we track snowfall patterns over time. All graphics are courtesy of the SNOTEL network.

Now that we completed a quick recap of last season, we’re free to start looking ahead to future snowfall. During the rest of August and September, expect weekly articles that will talk about what might be in store for the winter of 2016-2017!

JOEL GRATZ

PS - We have partnered with Ski.com to promote their giveaway of a FREE TRIP TO JAPAN! This is truly an awesome contest to enter. I skied Japan last winter and had an amazing time. Enter the contest by clicking here.