Wet summer ahead?
FRISCO — May brought drought-busting precipitation to much of Colorado, state climate experts said last week during their monthly Water Availability Task Force meeting in Denver.
The beneficial moisture erased a long-running drought in southeastern Colorado and also helped boost the streamflow outlook in the Rio Grande Basin, where a meager winter snowpack had lowered expectations for summer runoff.
By contrast, the far western third of the state is still designated as experiencing abnormally dry conditions by the National Drought Monitor, which also shows a pocket of moderate drought across western Gunnison and much of Delta counties.
The far northwestern corner of Colorado also saw well above-average precipitation, but longer-term dryness in that part of the state kept wildfire concerns in the forecast for late June.
Statewide, May 2015 was the wettest May on record since record-keeping started in 1895, surpassing 1995 and 1957. According to the National Weather Service, 31 weather stations reported May as the wettest month ever.
And even though the statewide snowpack never quite reached the average peak, precipitation at the mountain SNOTEL sites is 97 percent of normal for the water year (starting Oct. 1, 2014), an 11 percent improvement from a month ago.
In the San Miguel, Dolores, Animas and San Juan river basins June precipitation to-date is 350 percent of normal, and has already exceeded average total June precipitation. Since early May, the southwest corner of the state has seen about 10 inches of precipitation, wiping out the deficit of a multi-year drought.
Reservoir Storage statewide was at 107 percent of average as of May 1, and storage in the Colorado River Basin is at its highest levels in 15 years. The lowest storage levels are in the Upper Rio Grande and the basins of Southwestern Colorado, at 66 percent and 89 percent of average, respectively.
Climate experts say El Niño has continued to gain strength over the last few months and is poised to become a strong event, if not a “Super El Niño.” The last “Super El Niño” was in 1997 when Colorado experienced above average precipitation.
But NOAA climate experts cautioned against making predictions too early. Here’s an excerpt from a recent El Niño blog: “It’s important to remember, though, that we only have a handful of strong El Niño events in the historical record—seven since 1950. And only three of those saw Niño3.4 index values of 2.0°C or higher: 1972-73, 1997-98 and 1982-83)*. Imagine if we’d only had seven hurricanes in the history of record-keeping; it would make it much harder to understand and predict how a future hurricane could develop. So, while we’re confident that this El Niño event will continue, there’s still plenty of uncertainty about how it will evolve.”
All long term forecasting tools indicate normal to above normal precipitation in the coming months, with some indication that the monsoon season may come early.
The El Niño/seasonal outlook from NOAA’s Klaus Wolter.
And according to the Climate Prediction Center, Colorado is in the center of an area favored with changes for above average precipitation the next three months.