February 2018 Drought Update

2018 has started off warm and dry across most of the state with very few below average temperatures; and despite recent precipitation, it is unlikely that many basins in the southern half of the state will be able to reach average snow accumulation this season. 71 percent of the state is in some level of drought classification with 38 percent in moderate drought, 26 percent in severe drought and 8 percent classified as extremely dry. An additional 20 percent of the state is experiencing abnormally dry conditions. Mesa Verde National Park is currently experiencing the driest conditions on record (1923). Water providers are cautiously watching conditions but most have above average amounts of water in storage.

As of February 21, statewide precipitation at SNOTEL sites is 70 percent of average, with all of the basins improving as a percent of normal compared to last month. The North and South Platte basins have experienced the highest levels of precipitation in the state, at 95 and 103 percent, respectively. Despite recent gains, southern basins such as the Southwest basins of the San Miguel, Dolores, Animas & San Juan, Rio Grande and Gunnison basins remain below normal precipitation at 42, 51 and 55 percent respectively.

Conditions are also dry in the Arkansas Basin at 61 percent of average annual precipitation to-date. Several attendees pointed out a concerning lack of snow at foothill elevations in the Front Range.

Statistical analyses indicate that it will be hard for the state as a whole to reach normal snowpack given current conditions; however this varies from basin to basin with southern basins significantly drier than those in the north.

Reservoir storage statewide is at 115 percent of normal, with all basins above average. The Arkansas basin is reporting the highest average storage at 143 percent. The Gunnison basin has the lowest storage levels in the state at 104 percent of normal.

Both the SWSI and stream flow forecasts are based on conditions as of February 1, before several storms provided moisture to high mountain elevations. SWSI values declined compared to January 1, especially in the southwestern and south central part of the state. Stream flow forecasts are largely below normal statewide.

Water providers in attendance report their respective system storage levels are at or above average for this time of the year, but the lack of snowpack in concerning and being closely monitored. The majority of representation was from providers in the South Platte Basin, which is currently has the highest snowpack in the state.

Short term forecasts show that temperatures will be more seasonal with a normal chance of precipitation, however longer term forecasts indicate increased likelihood of below average precipitation and above average temperatures.

A weak La Niña remains in force for now, and forecasts indicate that warm and dry conditions are likely to persist through the spring. It is unclear what will happen during the summer months.

Statewide SNOTEL precipitation is well below average at 70 percent with the southern half of the state much drier than the northern basins.

North central Colorado has seen some improvements in drought conditions over the last month, while conditions have deteriorated in the southern half of the state. The Southwest corner of the state is the driest and unfortunately dry conditions are forecast to persist through spring.

Precipitation levels for communities in southeast Colorado, January-February 2017 and 2018: