Recent storms put snowpack levels in Wind River Basin at 88 percent of normalApr 17, 2013 By Eric Blom, Staff Writer
The snow water equivalent is up significantly over 2012 figures.
Snowstorms this week turned around the trend of shrinking snowpack in the Wind and Sweetwater river basins. Snow accumulation is raising hopes for a better growing season this summer than in 2012.
"We had a pretty good storm last week, but it affected some parts of the state more than others, and the same goes for the storm this week," National Resource Conservation Service hydrologic technician Ken Von Buettner said. "The percentage of the (snow water equivalent) went up based on the storms."
Snow water equivalent is roughly the amount of liquid water that accumulated snow, or snowpack, would melt into and is measured against a 30-year average.
The NRCS reported Wednesday that the snow water equivalent in the Wind River Basin stood at 88 percent of normal for the date. That figure is up from 79 percent seen April 1.
At this time last year, snow water equivalent measured only 75 percent of normal.
Accumulated moisture was also on the upswing in the Sweetwater River Basin, where snow water equivalent stood at 79 percent Wednesday. It was up 9 percent more than two weeks ago and 3 percent over the same time last year.
The upward trend reverses several weeks of the snow water equivalent decreasing compared to the average in both basins.
Experts think the increased snow pack will improve run-off forecasts.
"It will have a positive impact," Von Buettner said. "There will be more run-off now."
The next such projection will not come out until May 1, however.
Statewide, snowpack is in much better shape than the same time last year. According to an NRCS report released on Monday, the median snow water equivalent for Wyoming river basins on that date in 2012 measured 65 percent and was dropping. The low for the state was 0 percent in northeastern Wyoming's Belle Fourche River Basin, and the snowiest basin, that of the Madison River in northwest Wyoming, stood at 112 percent.
On Monday, the statewide basin average was up 15 percent from a week before and measured 92 percent of average. The high was 112 percent, which again was seen in the Belle Fourche River Basin. The low was 73 percent and is in the Lower North Platte River Basin in eastern Wyoming.
Record precipitation Tuesday pushed Riverton's total for April well above average for that period. On Tuesday, 0.36 inches of moisture fell, easily surpassing the record 0.21 inch from 2009, according to the National Weather Service, whose records for Riverton date back to 1995.
Tuesday's snowstorm brought Riverton's total for April to .87 inch, .30 inch above normal and .36 inch more than last year.
With the snowstorm, Riverton is right on track with the 30-year average precipitation for the year. So far in 2013, Riverton has seen 1.63 inches of precipitation, which is exactly normal and is .62 inch more than last year.
The snowstorm has pushed Riverton's snowfall this snow
season just over last's year's total by this date. It has reached 29.8 inches this year, and by this time in 2012, snowfall totaled 29.4 inches. The city has seen 9.9 inches of snow in April.
This year's precipitation in Lander is well above average and last year's numbers. By April 17, the county seat had seen 2.42 inches of precipitation in April alone and 4.82 inches since the beginning of January.
The total for the first half of April is 1.51 inches above the 30-year average, or more than double, and 1.43 inches more than the same period last year, again more than double.
The total for 2013 so far is 1.76 inches above normal and 2.16 inches more than the same time last year.
The April 16 snowstorm piled 9.34 inches of snow on a season that had already seen more snowfall than normal. By April 16, 90.4 inches of snow had fallen on the county seat, 11.2 inches more than average and 27.1 inches more than the same period in 2012.
Lander received the brunt of this week's storm just as it saw the most snow from last week's. In a report on Wednesday, NWS said the Lander area saw 8 to 11 inches this week.
A point 9.5 miles southwest of Lander was the snowiest in the state, however, where snowfall measured 19 inches. Casper Mountain saw the second most snow in the state where it totaled 18 inches.
Other points around Lander saw 11.5 to 13.5 inches.
NWS reported Riverton received 3 inches at the airport. A site two miles west of Riverton saw 4.5 inches. South Pass saw 8 inches, Hudson received 5 inches, 4 inches fell on Fort Washakie and Dubois, and Jeffrey City saw 3 inches.