Dry Conditions Persist for Another Month in Southwest Colorado Following Rapid Snowmelt.
Denver, CO – June 8th, 2022 With the exception of the Arkansas Basin, Southern Colorado continued receiving substantially less precipitation than mountains in the northern half of the state for a second month in a row. NRCS Hydrologist Karl Wetlaufer explains further “To put this in a historical context 24 out of 26 SNOTEL sites in the San Juan Mountains were in the bottom 10th percentile of precipitation received for the combined months of April and May. At nine of these sites this represented the lowest or second lowest amount on record.” Conversely, basins in Northern Colorado and the Arkansas received additional snow accumulations adding water to the system and prolonging the snowmelt season. Currently the South Platte basin has the most plentiful water year to date precipitation at 100 percent of the 30 year median followed closely by the Colorado and combined Yampa-White basins, both at 96 percent. On the low end, the Rio Grande and combined San Miguel, Dolores, Animas, and San Juan basins have 82 percent of median water year precipitation.
As a result of widely varying patterns of snowmelt timing and precipitation across the state over the last two months streamflow forecasts for the June-July period are extremely variable across Colorado. Dry and windy conditions along with dust on the snowpack forced early snowmelt at record rates in the Rio Grande and combined San Miguel, Dolores, Animas, and San Juan basins. This has left very little snow left to contribute to streamflow for the next two months and forecasts for only 33 percent of normal total volume in the Rio Grande and 26 percent in the combined basins of the southern San Juans. However, Wetlaufer comments “While the outlook for the coming months is for very low streamflow forecasts in southwest Colorado things do improve further north in the state. Forecasts in the North Platte and South Platte basins are for 99 and 92 percent of normal for June-July, respectively.”
Reservoir storage also continues to vary considerably across the state. This is a result of both conditions this water year as well as the cumulative effect of multiple warm and dry years in southern Colorado particularly. Currently no major basins in the state are holding above median reservoir storages. According to the US Drought Monitor 99 percent of Colorado is currently under some form of drought designation and 57 percent of the state is classified as having “Severe” to “Exceptional” drought. Given this and the fact that the vast majority or reservoir storages and streamflow forecasts in the state are below normal water supplies will have to be watched closely for the foreseeable future.
* San Miguel-Dolores-Animas-San Juan River basin
* *For more detailed information about February mountain snowpack refer to the June 1st, 2022 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.