The USDA Natural Resources Conservation Service in Bozeman reports that above-average temperatures during the first two weeks of June has impacted snowpack except at the highest elevations. This could affect streamflow levels later in summer.

The high daily-average temperatures and overnight above-freezing temperatures caused above-average snowmelt rates across the state, causing rivers and streams to rise and, in most cases, reach their snowmelt-driven peaks during the middle to latter part of the month.

“There may be a few river systems that have yet to see their peak, systems where peaks are typically driven by the high-elevation component of snowmelt,” NRCS water supply specialist Brian Domonkos said.

Abundant precipitation during the second half of May followed two weeks of warm and dry weather and helped some watersheds east of the Continental Divide improve their water year-to-date precipitation.

“The timing of precipitation is critical to the greater water system as this is the time of the year when dam tenders are filling reservoirs while irrigators begin to draw water,” Domonkos said. “Continued precipitation during the month of June will certainly be welcome starting into the hot summer months and persistent active storm patterns become less frequent.”

Snowpack in the Flathead River basin was 102 percent of median and 66 percent of last year. The snowpack in the basin declined by 13 percent in May. For detailed snowpack information, visit online at www.wcc.nrcs.usda.gov/ftpref/data/snow/basin_reports/montana/wy2013/basnmt6.txt.

The June-July streamflow forecast for the Flathead River basin is 96 percent of average and 63 percent of last year. For detailed basin streamflow forecast information, visit online at ftp://ftp.wcc.nrcs.usda.gov/support/water/provisional_forecasts/montana/mt.txt.