Snow totals remain high

Alexis Barker
NLJ News Editor
 
“We’re above average (even above last year) with snow levels in the hills, higher elevations look really good,” said Jason Nehl, a U.S. Department of Agriculture resource specialist in Sundance, in an email with the March 1 Black Hills Snow Course Reading report. 
According to the report, both areas closest to Newcastle – Little Bear Run and Mallo, are sitting well above the 30-year median for snow water equivalent. 
Snow water equivalent, or SWE, is a common snowpack measurement for the amount of water contained in the snowpack.
 It can be thought of as the depth of water that would theoretically result if the snowpack were to melt instantaneously, according to Nehl. 
Little Bear Run, with an elevation of 6,240 feet, is currently sitting at 24 inches of snow. Mallo, with an elevation of 6,420 feet, has a current snow depth of 36.9 inches. This snowpack equates to 4.6 inches and 8 inches of snow water equivalent for the two areas. 
For Little Bear Run, this is 139% of the 30-year median of 3.3 inches of snow water equivalent while Mallo is at 133% of the 30-year median for the area of 6 inches of snow water equivalent. 
At this time last year, Little Bear Run had a snow water equivalent of 4.2 inches, while Mallo’s was at 7.1 inches. 
But what does this mean moving into the warmer months?
Nehl said that the data can be “kind of tricky” when trying to forecast long-term conditions in the area because the Black Hills and surrounding areas are at such a low elevation, as far as mountains go, and are much more subject to drastic changes than higher elevations. 
“To clarify a bit, we can have a good snowpack in January or February that looks like it will translate to heavy stream flows in May,” Nehl said. “Then, we can have a warm two-to-three-week period that melts out the majority of the snowpack, and we end up with below-average spring runoff.” 
Speaking of spring runoff, the Feb. 27 flood potential outlook from the National Weather Service in Rapid City states that the “probability of spring flooding through June ranges from around average across northeastern Wyoming and far northwestern South Dakota, to above average across south central South Dakota.” 
“The higher spring flood risk for some areas is due to saturated soil conditions, higher river levels and above average snowfall this winter season in parts of the Cheyenne River, White River, Bad River, lower Grand and lower Moreau River Basins,” the outlook says. 
The potential for ice-jam-related flooding will remain high until the ice is off the rivers, streams and lakes, according to the outlook. 
“Due to the warmer than average temperatures this winter, the ice thickness is below average. Therefore, the duration and extent of any ice jam flooding that may occur is not expected to be as bad as last year,” the outlook states. 
For the Black Hills and higher elevations, flooding from snowmelt will typically begin in late April and early May.
“The flood potential is still very dependent on weather conditions this spring. The amount of additional snow and rain, as well as the timing of peak river and stream flows, will have significant effect on the severity of flooding,” the outlook states.