Heavy rains across the western half of the country, including those that brought dramatic flooding to Colorado, eased drought in the week that ended Sept. 17, according to the U.S. Drought Monitor map. But drought expanded slightly in the Midwest and South.
The area of the 48 states in moderate drought or worse fell to 48.19 percent, down from 50.69 percent the week before. Other categories of drought likewise declined, with exceptional drought, the worst category, all but eliminated from the map, covering only 0.43 percent of the 48 states, down from 1.25 percent a week earlier. The last time the area of exceptional drought was so small was June 26, 2012, when it covered 0.41 percent of the contiguous states.
Several locations received a good portion of their normal annual rainfall within just a few days. “The robust southwest summer monsoon exploded with copious rainfall (6 to 12 inches, locally over 18 inches near Boulder, Colo.) across portions of New Mexico and Colorado, producing severe flash flooding, loss of lives, and the destruction of property and infrastructure,” said this week’s U.S. Drought Monitor author, David Miskus, in narrative accompanying the map.
The rains eliminated exceptional drought from New Mexico and Arizona and substantially reduced the extent and intensity of drought in those states. Exceptional drought also disappeared from Nebraska and Kansas this week.
Although southeast Colorado still has a shrinking patch of exceptional drought, the extent and intensity of drought there also declined dramatically. The area in moderate drought or worse fell by nearly a third, to 64.59 percent from 93.08 percent a week earlier.
Wyoming, Montana, Idaho, Nevada, Utah and North Dakota also improved.
Drought expanded in the Midwestern and southern states of South Dakota, Illinois, Indiana, Missouri, Arkansas, Louisiana and Mississippi.
U.S. Drought Monitor authors synthesize many drought indicators into a single map that identifies areas of the country that are abnormally dry (D0), in moderate drought (D1), in severe drought (D2), extreme drought (D3) and exceptional drought (D4). The map is released each Thursday based on data through the previous Tuesday morning.
The U.S. Drought Monitor map is jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the National Oceanic and Atmospheric Administration, the USDA, and about 350 drought observers across the country. Miskus is with NOAA’s Climate Prediction Center.
Statistics for the percent area in each category of drought are automatically added to the U.S. Drought Monitor website each week for the entire country and Puerto Rico, for the 48 contiguous states, for each climate region, and for individual states. U.S. Drought Monitor data online goes back to January 2000.
http//drought.unl.edu/MonitoringTools/USDroughtMonitor/DroughtMonitorTips.aspx
U.S. Drought Monitor map, statistics and narrative summary: http://droughtmonitor.unl.edu
Drought Impact Reporter: http://droughtreporter.unl.edu
USDA’s weekly “Agriculture in Drought” analysis:
http://www.usda.gov/oce/weather/Drought/AgInDrought.pdf
National Climatic Data Center’s State of the Climate Drought Summary: http://www.ncdc.noaa.gov/sotc/drought/
U.S. Monthly Drought Outlook:
http://www.cpc.ncep.noaa.gov/products/expert_assessment/mdo_summary.html
U.S. Seasonal Drought Outlook:
http://www.cpc.ncep.noaa.gov/products/expert_assessment/sdo_summary.html
-- Kelly Helm Smith, National Drought Mitigation Center