Click here to read the release (Brian Domonkos):
Similar to what was observed throughout the 2019 water year, 2020 has so far displayed widely varying patterns of precipitation and snow accumulation month-to-month and across the mountain basins of Colorado. October exhibited the continued dry spell of the late summer and early fall in southern Colorado, while the northern basins received above normal precipitation. Precipitation was more evenly distributed in November. December brought above normal precipitation to all basins except the combined Yampa, White, and North Platte in northwest Colorado. This ample December accumulation was mostly received as snow across the state. “Increased accumulation as snow in December compared to the drier previous months has led to above normal snowpack and below normal water year precipitation. As of January 1st, water year-to-date precipitation was 92 percent of normal and snowpack was 119 percent” explains NRCS Hydrologist Karl Wetlaufer. All individual major basins in the state are currently holding above normal snowpack as well, ranging from 104 to 129 percent of normal.
The contributing factors of snowpack and precipitation have led streamflow forecasts to be relatively consistent across the state. “While it is common to see notable geographic trends in forecasts across the state, current water supply forecasts are generally for near to slightly below average volumes in all major basins of Colorado. Ninety percent of water supply forecasts in Colorado currently lie between 85-115 percent of their average volumes.” Wetlaufer notes. On the high end, the average of forecasts in the Arkansas Basin are for 104 percent of normal volumes. On the low end, the Gunnison and combined San Miguel, Dolores, Animas, and San Juan Basins have an average forecast value of 88 percent of normal.
Statewide reservoir storage has remained above average only dropping a few percentage points over the last few months to where it resides at 106 percent of average. Only the Arkansas and Upper Rio Grande Basins are holding below average storage at 98 and 86 percent of average, respectively. All other basins in the state are carrying between 104 and 129 percent of their average reservoir storage for this time of year.
Overall things are off to a good start with respect to prospective water supply with ample reservoir storage and above normal snowpack. We have just surpassed the accumulation of 50 percent of what the normal snowpack peak is, which generally occurs in April. That said, there are still several months until the primary snowmelt runoff season and a lot can change so it is always worth keeping an eye on current conditions as time progresses.
For more detailed information about January 1 mountain snowpack refer to the January 1, 2020 Colorado Water Supply Outlook Report. For the most up to date information about Colorado snowpack and water supply related information, refer to the Colorado Snow Survey website.