Lack Of Spring Showers Lower Montana River Forecasts
The average precipitation in most of Montana was about 50 percent of normal in April, including Missoula and Hamilton areas. The snowpack is above average in only a few river basins of the state. That snow is critical to good streamflow through the summer. The developing high water season runoff is expected to be below what was expected only a month ago.
The recent warm days have added to the snowpack melt. Lucas Zukiewicz, Natural Resources Conservation Service Montana water supply specialist, was quoted in the monthly NRCS water supply report news release: "The temperatures at the end of April and beginning of May were the tipping point for the snowpack at the mid and high elevations. As of now, all elevations are melting at a pretty good clip." Nineteen of the automated SNOTEL sites have "melted out" (no snow) about two to three weeks ahead of schedule, Zukiewicz noted.
It's not all bad, though. NRCS is forecasting the possibility of slightly below average streamflows because of heavy snowfall in October and February. In the Bitterroot and Clark Fork river basins, for instance, the snow water level is about 90 percent of average.
On the other hand, Southwest Montana, in the area of the Jefferson River, has been dry since last summer and is expected to have well below normal streamflows for spring and summer. He said, "Water users in this area and downstream on the Missouri, should be aware of this possibility, especially if May and June Precipitation fail to materialize. The Associated Press recently reported lower than normal levels already at Ft Peck Reservoir. Zukiewicz said the final Water Supply Outlook for this year will posted in early June.