From the Natural Resources Conservation Service (Mike Gillespie):
Colorado’s latest snowpack data, compiled by the USDA- Natural Resources Conservation Service (NRCS), shows the profound impact that a cool and wet May can have on water supplies, in terms of both timing and quantity. While the state’s mountain snowpack typically reaches its seasonal maximum in mid-April, this year’s snowpack finally reached its peak in late May across northern Colorado, about three weeks later than normal. Not only has the cool weather delayed any significant melting across the higher elevations, but the continued wet weather pattern has contributed to additional snowpack accumulations across the high country. This year’s June 1 snowpack readings show record high snowpack levels for this date across most of the northern and central mountains, according to Allen Green, State Conservationist with the NRCS.
The forecasted runoff throughout the Yampa, White, Colorado, North and South Platte river basins this year is well above average, and in some cases will be two to three times higher than the average for the April through July forecast period. Meanwhile, across southern Colorado, snow melt is well underway after reaching below average seasonal totals. Runoff forecasts in the Rio Grande, San Juan, Animas, Dolores and San Miguel basins are generally below average, with the lowest anticipated runoff occurring along those streams flowing from the Sange de Cristo Mountains in southern Colorado.
Additional snow accumulations in late April and into May have considerably improved the water supply outlook across most of the state. Runoff volumes in the Gunnison basin and the Arkansas headwaters have increased this month as well, and are now above average.
At this late stage in the melt season, temperatures will play an important role in how rapidly snowmelt will occur. “There remains a tremendous amount of snow across northern Colorado. A gradual and even meltout would help minimize impacts”, said Green. Water managers will be monitoring temperatures at automated SNOTEL sites, including the daily high and low temperatures as the melt progresses through June. Periodic breaks in June temperatures might help keep melt rates in check. On the positive side, this year’s water supplies will be the best in more than a decade allowing for full reservoirs and abundant water supplies for irrigation well into the summer growing season.