Snow accumulations between March 1 and March 15 have been the highlight of this winter, coming in at near record levels across much of the state. At the end of March, snowpack across the state of Colorado is 136 percent of median, up 24 percent from last month. The combined San Miguel, Dolores, Animas & San Juan Basins posted the largest gain of 35 percent, followed by the Upper Rio Grande, Gunnison and Arkansas at 30, 32 and 25 percent respectively.
Basin-wide snowpack improvements elsewhere in Colorado were slightly more modest. These improvements through March pushed snowpack past a significant milestone, “All individual major basins in the state are now above the typical annual snowpack peak, which often leads to a favorable water supply in each basin,” notes Brian Domonkos, Colorado Snow Survey Supervisor with the Natural Resources Conservation Service.
March snowpack improvements showcase the impressive changes, but equally noteworthy are current snowpack totals for the water year beginning on October 1. Snowpack observation points within the San Miguel, Dolores, Animas & San Juan combined basins indicate 157 percent of median, while snowpack in the Gunnison, Arkansas, Rio Grande, and Colorado indicate 150, 149, 145 and 130 percent of median respectively. “Current snowpack values in some individual basins on April 1, 2019 translate to nearly double or triple levels seen during this same time last year,” comments Domonkos. These improvements over last year are welcomed in restoring water supplies significantly depleted after last year’s drought.
Similar to snowpack, March precipitation was particularly impressive, amounting to 183 percent of average for the state. Water year-to-date precipitation across the state is now 123 percent of average. Precipitation totals in the Gunnison and combined southwest basins are no less impressive each at 133 percent of average for the water year to date.
By the numbers, March is typically the second wettest month of the year in Colorado, meaning accumulations this March were particularly impactful. While reservoir storage levels across the state have seen little increase in recent months, current snowpack levels are poised to increase storage levels across much of the state as the snow begins to melt. Most volumetric streamflow forecasts into spring and summer range from 100 to 150 percent of normal. Basins that have the highest forecasts, namely in Southern Colorado, are those that had the least streamflow last year, which should be particularly beneficial for water supply conditions in those areas.
For more detailed information about mountain snowpack, visit: wcc.nrcs.usda.gov.