@CWCB_DNR: January 2018 #Drought Update

Colorado Drought Monitor January 16, 2018.

Click here to read the update from the Colorado Water Conservation Board/Colorado Division of Water Resources (Taryn Finnessey, Tracy Kosloff):

The start of Water Year 2018 has been warm and dry across most of the state. However, recent precipitation in the northern half of the state has helped those basins, while storms have largely missed the southern half of the state. November 2017 was the warmest November on record, while December was the 7th warmest on record. The three month period from October through December was 3.8 degrees Fahrenheit above the long term average, making it the warmest October- December on record (123 years). This warmth resulted in the state as a whole breaking more than 1700 warm records during the same time frame.

 As of January 17, statewide precipitation at SNOTEL sites is 62 percent of average. The North and South Platte basins have experienced the highest levels of precipitation in the state, at 92 and 100 percent, respectively. Southern basins such as the Southwest basins of the San Miguel, Dolores, Animas & San Juan , Rio Grande and Gunnison basins are well below normal precipitation at 25, 32 and 43 percent respectively. The Arkansas Basin is also well below normal with only 57 percent of average annual precipitation to-date.

 Many basins have water year to-date snowpack that is tracking most closely with the minimum accumulation on record. While this does not mean that the year will end that way, large deficits in precipitation become harder to make up for the further along in the season we get.

 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 northern basins significantly better off than those in the south.

 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.

 24 percent of Colorado is classified as abnormally dry (D0), while 76 percent is classified as experiencing drought. 53 percent is categorized as moderate drought (D1), while 23 percent is categorized as severe drought (D2).

 SWSI values have dropped quickly over the last few months; much of the western half of the state is classified as extremely dry or slightly dry. The Animas Basin is the lowest in the state at -3.67. The big Thompson is the highest at 2.06.

 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.

 Short term forecasts show that temperatures will be more seasonal with about average precipitation for much of the state over the next two weeks.

 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.

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