@CWCB_DNR: September 2020 #Drought Update

Click here to read the update (Megan Holcomb/Tracy Kosloff):

As the end of the water year draws near, Colorado experienced the hottest August on record since record keeping began in 1895. As of September 15th, the entire state is covered in dry conditions with over 50% of our state in extreme or exceptional drought. Minor temporary soil moisture improvements were made with the September 9th snowfall. The early storm broke numerous records including a record low temperature, earliest freeze, and the shortest number of days between a 100 degree day and a measurable snowfall. This widespread precipitation event extended over the eastern plains and resulted in over 10 inches of snow in north central Colorado and the San Luis Valley ‐ with some areas logging up to 18 inches. While this event brought SNOTEL measures to near average precipitation for September, August and September are still extremely (or near record) dry months for the state. On September 21, 2020, Governor Polis expanded Drought Plan activation to all 64 Colorado counties.

Colorado Drought Monitor September 22, 2020.

The Sept. 24 U.S. Drought Monitor, logged 0.4% of the state in D4 (exceptional) drought conditions; D3 (extreme) drought in 50% of the state; D2 (severe) drought covering 38%; and D1 (moderate) drought covering 11% of the state.

The 90‐day Standardized Precipitation Index (SPI) (June 22 to Sept 19) shows consistent dryness across the state with deeper shortfalls more prevalent throughout north central Colorado and front range. Below average precipitation is expected to continue over the next two weeks.

Tropical Sea Surface Temperatures indicate La Niña conditions, and the CPC issued a La Niña Advisory. There is now a 75% chance that weak La Niña conditions will continue throughout the fall/winter, increasing the likelihood of warm extremes for the state and less snow for the southern mountains and eastern plains.

The NOAA Climate Prediction Center three month outlook maps indicate higher chances for above average temperatures over fall and winter with a slightly enhanced chance of below average precip.

Statewide reservoir storage is currently at 85% of average, down from 90% last month. Storage in the northern half of the state is near average while the southern half of the state ranges from 67% to 77% of average.

Municipal water providers continue to report increased demands and most municipalities are experiencing normal to slightly below normal storage. Water providers are monitoring conditions as they consider the need for future restrictions. Currently, the following municipalities have active watering restrictions, due to the compounding impacts of wildfire: Glenwood Springs (active Aug.15), Fort Collins (beginning Oct 1)

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