Snowpack hanging tough in the mountains
May 14, 2014
Steamboat Springs — The Yampa River has been falling since May 8 and is expected to do so through Thursday before a warming trend causes the river to begin to rise again. And spring runoff season appears to be far from over.
The snow at the summit of Buffalo Pass was hand-measured by the U.S. Forest Service at 147 inches Tuesday, the same depth it was on March 31, in spite of numerous mild days in April and May that pushed valley temperatures into the 60s. Also, a remote measuring device near the West Summit of Rabbit Ears Pass reports the snow depth there still is 69 inches. The 34.1 inches of water contained in the snowpack on the West Summit is 166 percent of the median, according to the Natural Resources Conservation Service, and all of that water has yet to flow down the tributary streams into the river.
Could the Yampa River flood parking lots along U.S. Highway 40 this spring when runoff begins in earnest, like it did in 2011? Aldis Strautins, a hydrologist with the National Weather Service in Grand Junction, said Wednesday that ultimately the answer to that question will depend on weather conditions. But he consulted the Colorado Basin Forecast Center to confirm that the Yampa is expected to peak below flood stage, but possibly not by much.
"There's a 10 percent chance the Yampa will peak at 5,500 cubic feet per second, which compares to flood stage at 5,900 cfs," Strautins said. "The peaks are really weather dependent, and it's hard to predict beyond seven days out."
Flood stage on the Yampa at Fifth Street also is described as a measurement of 7 feet on the gauge.
Forecast Center hydrologist Ashley Nielson told the Steamboat Today on April 22 that this year's snowpack doesn't measure up to 2011.
"There's a lot less snow than what we had in 2011," Nelson said in late April.
History suggests the Yampa typically would peak sometime in the next three weeks — during the last two weeks in May or the first week in June. The Yampa where it flows beneath the Fifth Street Bridge in Steamboat peaked at 2,830 cubic feet per second May 27, 2013. The year before, in 2012, it peaked unusually early at just 1,570 cfs on April 27.
The preceding two years, the Yampa happened to peak on June 7. And it was June 7, 2011, that it peaked at 5,200 cfs, causing the evacuation of a parsonage at Steamboat Christian Center, where the river was flowing through the parking lot.
With the river flowing at just 1,010 cfs on Wednesday afternoon, and above average snowpack persisting in the mountains, this may be a runoff season when the peak does not arrive until June.
One has to search back to the 1990s to find a year when the river peaked later than June 7. From 1998 until 2007, it peaked anywhere between May 21 to May 30. But look a little deeper into the 90s at the U.S. Geological Survey site and one sees that the river peaked at a modest 3,280 cfs on June 17, 1993, and at 3,720 cfs on June 16, 1995.
The spring runoff seasons of 1982, 1983 and 1984 also were notable. The river peaked at 4,300 cfs on June 17, 1982, at 5,260 cfs on June 25, 1983, and at 5,670 cfs on May 25, 1984. On this date in 1984, the Yampa in Steamboat already was flowing at 4,570 cfs, the highest ever recorded on May 14.