Colorado Water Conservation Board – March 2017 Drought Update

February of this year was the second warmest February on record, and the warmest since 1954. Well above average temperatures have continued into March. Precipitation in February was average but has slowed considerably with only 29 percent of average month –to-date in March. However, the forecast for the next two weeks indicates that the state will likely see cooler temperatures and more significant moisture. Demand has already increased for municipal water providers, indicative of an increase in outdoor watering typically not seen for another month. Agricultural producers are also expressing concern and are hopeful that forecasted storms will materialize and help to alleviate worsening drought conditions. Fires have already been an issue in the foothills and on the eastern plains.

Statewide water year- to- date snowpack as of March 20th is at 116 percent of normal, down from 133% of normal on March 1st. The Upper Rio Grande currently has the lowest snowpack in the state at 105 percent of normal while the basins of the Southwest and Gunnison have the highest snowpack at 130 percent of normal.

Above average temperatures have resulted in snowpack beginning to melt off at some mountain locations. All basins have seen a decline in snowpack with respect to normal since March 1st due to combined dry and warm weather. This is typically the snowiest month of the year in the Colorado mountains. Normal peak accumulation typically occurs around April 9th,so the possibility remains to return to snowier weather and accumulate more snowpack potentially providing a higher peak snowpack this year.

Following an average February, all basins are well below average for precipitation thus far in March, with accumulation ranging from a low of 19 percent in the Gunnison to a high of 55 percent in the Yampa & White. Statewide March-to-date precipitation is only 29 percent of average.

Reservoir storage statewide remains high at 107% of normal. The Yampa & White River basins along with the Southwestern basins have the highest storage levels in the state at 127 and 114% of average, respectively. The Upper Rio Grande has the lowest storage levels at 91% percent. Reservoirs are already beginning to see inflow from the early snowmelt.

Reservoir storage and above average streamflow forecasts have resulted in the Surface Water Supply Index (SWSI) indicating slightly wet to moderately wet across most of the state, with the eastern plains showing less available water than the west slope.

Streamflow forecasts, while still above average, have been trending downward over the last month and without additional snow accumulation are expected to continue decreasing.

Neutral ENSO conditions are present, and are favored to continue through spring, with the possible development of an El Nino this summer. The April-June forecast looks dry for the season, with the promise of an enhanced monsoon season based on current analogues. Should an El Niño develop this summer, precipitation during the latter half of the growing season becomes more favorable.

Short term forecasts show an increased probability of precipitation across most of the state over the next two weeks with widespread 1-4 inches of moisture expected over the mountains and northeastern plains.

The US Drought Monitor illustrates persistent dry conditions east of the continental divide in Colorado. The majority of this (37%) is moderate drought. Over the last few weeks warm and dry conditions have led to worsening drought conditions throughout this region and an expansion of severe drought (D2) conditions along the northern Front Range.

Well above average snow accumulation in December and January and average February snowfall has led to near normal snowpack statewide. However, March has been extremely warm and dry to-date and spring melt has already begun to occur below 10,000 feet.

The near record warmth experienced in February has continued into March with month to-date temperatures well above average across most of the state. High temperatures along with very little precipitation has resulted in more severe drought on the eastern plains and increased fire risk.