#Snowpack Above Normal but #Water Supply Forecasts Lower After Dry Fall — NRCS #Colorado Snow Survey

Click here to read the release from the NRCS (Brian Domonkos):

Water year 2020 has continued to be a mixed bag of conditions across Colorado and month-to-month. This has left the state with above normal snowpack and below normal water year precipitation. This came about after a dry October and early November before the start of the primary snowpack accumulation. “After a particularly dry late summer and fall, December provided substantial snow accumulation in Colorado. January then followed with mostly below average precipitation with southern Colorado being the driest, an area that received the most accumulation in December” notes NRCS Hydrologist Karl Wetlaufer. Statewide snowpack was 109 percent of normal on February 1st and water year to date precipitation was 88 percent. While above normal snowpack exists across the state the precipitation deficit leading to and entering winter have led streamflow forecasts to be mostly below average across the state. Forecasts have overall been following precipitation trends across the major basins of the state.

Statewide snowpack February 8, 2020 via the Colorado Snow Survey (NRCS) interactive application.

The most plentiful water supply forecasts currently exist in the combined Yampa and White, Arkansas, and South Platte River basins where the average of forecast values is 98, 97, and 96 percent of normal, respectively. Outlooks for spring and summer streamflows are notably less in basins further to the west and southwest. In the Colorado basin the average of forecasts is for 91 percent of average with the lowest values existing in the western half of the basin. In the Gunnison forecasts average out to be 81 percent of average. At the low end the Rio Grande and combined San Miguel, Dolores, Animas, and San Juan basins are forecasted for 77 and 76 percent of average, respectively.

Reservoir storage has steadily dropped statewide throughout the water year, with respect to normal, but storage in some basins has gone up and some have gone down. Currently the only basins holding below average storage are the Rio Grande and Arkansas. The total range of storage values is from a low of 85 percent in the Rio Grande to a high of 127 in the Yampa basin with a statewide average of 105 percent. Details of snowpack and reservoir conditions by basin can be seen in the table below.

At this point in the season Colorado has built about two-thirds of what the normal peak snowpack is in mid-April. “While the dry early season conditions have led to forecasts lower than the snowpack may suggest it is still encouraging to have the snowpack that we do with a few more months of accumulation left. That said, as the last two winters have shown things can continue to be variable and a lot can still change. In the meager 2018 season the snow we have now was all that accumulated by the peak and we have the same amount as we did at this time last year which turned out to be huge by the end of the season” Wetlaufer comments. With respect to Wetlaufer’s comments it is worth noting that much of Colorado is actively being hit by a large winter storm at the time of this writing.

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