Here’s the discussion from the Colorado Basin River Forecast Center:
The Colorado Basin River Forecast Center (CBRFC) geographic forecast area includes the Upper Colorado River Basin, Lower Colorado River Basin, and Eastern Great Basin.
Water Supply Forecast Summary:
The month of April was generally dry over much of the CBRFC forecast area. While the month was not void of storm systems the greatest precipitation impacts were limited to the northern Bear River Basin, Yampa River Basin, Colorado mainstem headwaters, and parts of the Gunnison River Basin. In every month of the 2018 water year dating back to last October at least some part of the Colorado River Basin or Great Basin has experienced very dry conditions with monthly precipitation less than 50 percent of average. Only February of 2018 saw widespread precipitation that was near or above average in areas that are the primary contributors to the April-July runoff. However, even then impacts were limited to the upper Colorado River Basin as very dry conditions were widespread in the Great Basin.
April-July water supply volume forecasts increased from those issued in early April in parts of the Yampa River Basin, Colorado River headwaters, eastern headwaters of the Gunnison River Basin and some headwaters of the Green River Basin in Wyoming. The most significant decreases from early April occurred in the Dolores River Basin, Sevier River Basin, and Duchesne River Basin.
Forecasts are highest with respect to average in the Green River Basin of Wyoming, Colorado mainstem headwaters, and in northern parts of the Bear River Basin. Lowest forecasts with respect to average are in the southern basins of the forecast area and include the Dolores River Basin, San Juan River Basin, Sevier River Basin, and Virgin River Basin.
April-July unregulated inflow forecasts for some of the major reservoirs in the Upper Colorado River Basin include Fontenelle Reservoir 900 KAF (124% of average), Flaming Gorge 1000 KAF (102% of average), Blue Mesa Reservoir 350 KAF (52% of average), McPhee Reservoir 62 KAF (21% of average), and Navajo Reservoir 200 KAF (27% of average). The Lake Powell inflow forecast is 3.00 MAF or 42% of average.
