Background: The 2017-2018 Drought in the Southwest
According to the U.S. Drought Monitor’s drought severity designations, “Abnormally Dry” conditions crept into the Southwest region in October 2017 and deepened into widespread “Moderate Drought” in November 2017. The region was in “Severe Drought” by January 2018; “Extreme Drought” by March 2018; and “Exceptional Drought” by May 2018. The “Exceptional Drought” lingered in the region until January 2019. In 2018, the region experienced more than 45 weeks in drought.
Quarterly Climate Impacts and Outlook for the Missouri River Basin December 2018 – February 2019. Dated March 2019.
With a warm start and a cold end, average temperatures for the winter were only slightly below normal across the Missouri River Basin. Persistent cold, along with frequent snowstorms during the latter half of winter, allowed the snowpack to build across the Plains.
Long-term drought in the Southwest will continue to impact reservoirs and water supply
- Weak El Niño conditions developed in January; an “El Niño Advisory” is in effect as of 14 February 2019.
- Since October 2018, the region has experienced mostly wetter and cooler conditions than 1981-2010 normals (Fig 1).
- Extreme and Exceptional Drought in the Southwest has decreased in extent from 25% in October 2018 to 5% in February 2019 (Fig 2).
- Several years of above-average precipitation and run-off will be needed to alleviate the water supply deficits r
Quarterly Climate Impacts and Outlook for the Missouri River Basin March – May 2020. Dated June 2020.
Temperatures were largely near normal across the region this spring, with the exception of Colorado, which had its 12th warmest spring since records began in 1895. Although flooding impacted parts of the region this spring, warm and dry conditions early in the season reduced the flood risk and subsequent impacts.
Outdoor recreation is a major contributor to the Intermountain West’s economy, but the future viability of many businesses—particularly small businesses—in the industry is threatened by their drought vulnerabilities and the region’s projected increases in drought severity and frequency.
Quarterly Climate Impacts and Outlook for the Missouri River Basin September – November 2018. Dated December 2018.
Overall, it was a cool autumn across the Missouri River Basin, with widespread temperature departures in the 2-6°F below-normal range. While precipitation varied across the region, it was a particularly wet autumn for an area extending from eastern New Mexico through Wisconsin.