On April 5, The US Army Corps of Engineers issued the “Upper Missouri River Basin April 2018 Calendar Year Runoff Forecast. The report summary states “the annual runoff forecast for the Missouri Basin above Sioux City, IA is 30.2 MAF, 119% of average. Looking short-term, runoff in April is forecast to be above average for the upper Basin – about 120% -- particularly in the Fort Peck and Garrison reaches due to the remaining plains snowpack, wet soil moisture conditions, and precipitation outlooks.
Looking a bit further down the road, the runoff forecast for the May through July period in the Fort Peck and Garrison reaches – the two reaches that are affected by mountain snowpack – is 130% of average. Runoff in these two reaches is mostly influenced by the above-average mountain snowpack, as well as the above-normal precipitation outlook for Montana and the current soil moisture content.
View the full narrative: http://www.nwd-mr.usace.army.mil/rcc/reports/runoff_narrative.pdf