Much of West reports record-fast meltdown under El Niño heat
April storms helped boost Colorado’s statewide snowpack to above average, but two river basins in the southern part of the state continue to report below normal readings.
The state’s mountain areas benefited the most from a series of wet, El Niño-fueled storms, bringing precipitation for the water year to average, according to Brian Domonkos, the Colorado snow survey supervisor for the USDA Natural Resources conservation service.
“At this time last year the water supply outlook was grim at best,” Domonkos said. “Colorado’s current snowpack and precipitation levels are right where we want to be this time of year. Elsewhere in the Western United States seasonal snowpack during 2016 succumbed to early spring warming and did not recover as Colorado did from recent storms,” he added.
With temperatures in the West far above average in April, snowpack across the region dwindled at a record pace, the NRCS reported after studying data from about 800 high elevation SNOTEL sites.
In Colorado, the seven major mountan watersheds all saw 90 percent of normal April precipitation or better. The Arkansas, Upper Rio Grande and combined Yampa, White and North Platte Basins received 120 percent of normal or better precipitation.
Snowpack metrics indicate that the North and South Platte River basins have the best snowpack in the state at 114 percent of normal. The Arkansas saw the greatest improvement in April.
The snowpack didn’t improve nearly much in the Upper Rio Grande and combined San Miguel, Dolores, Animas and San Juan Basins, but there was abundant rain in the Upper Rio Grande, which helps with basin’s overall moisture situation.
But the readings from that basin also show how global warming can affect water supplies and resource management by shifting the timing and type of precipitation. Getting rain in spring may green up fields and pastures, but it doesn’t keep the rivers and streams flowing late summer, when water is needed most.
Reservoir storage is also above average for this time of year, at 112 percent of average. Storage dropped in the Rio Grande, Arkansas and combined Yampa, White and North Platte watersheds, the NRCS reported.