The U.S. Drought Monitor map for the seven days ending September 11, 2012, reveals no relief for parts of the southern Plains, with extreme and exceptional drought expanding in southeastern Oklahoma and southeastern Texas.
In the northern Plains, severe drought expanded in western North Dakota, and extreme drought increased slightly in central South Dakota as agricultural conditions worsened. To the east, Minnesota and Wisconsin saw expansions in moderate drought and abnormal dryness. Severe drought expanded to include Beltrami, Clearwater, and Mahnomen counties in northwestern Minnesota.
The Drought Monitor brought some positive news as well. Conditions improved in portions of the Mid Atlantic, Midwest, and Northeast when a strong cold front during the weekend brought widespread rains to the area. In the Southwest, monsoonal rains have helped to ease drought conditions over portions of Arizona and the Great Basin. One-category improvements are shown across southern Arizona, southeastern California, southwestern Colorado, southern Nevada, and southwestern Utah.
Statistics released with the map showed that 53.70 percent of the country was in moderate drought or worse, up slightly from 53.06 percent the week before, and the largest percentage recorded this summer. The map showed 34.97 percent in severe drought or worse, down from 35.53 percent a week earlier; 17.63 percent in extreme drought or worse, compared with 17.93 percent the week before; and 5.20 percent in exceptional drought, compared with 5.13 percent the preceding week.
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 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 U.S. Department of Agriculture, and about 350 drought observers across the country. It is released each Thursday based on data through the previous Tuesday.
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: http://drought.unl.edu/MonitoringTools/USDroughtMonitor/DroughtMonitorTips.aspx
The National Climatic Data Center maintains drought data based on the Palmer Drought Severity Index, calculated to the beginning of the historic record: http://www1.ncdc.noaa.gov/pub/data/cmb/sotc/drought/2012/06/uspctarea-wetdry-mod.txt
U.S. Drought Monitor: http://droughtmonitor.unl.edu
Seasonal Drought Outlook: http://www.cpc.ncep.noaa.gov/products/expert_assessment/seasonal_drought.html
U.S. Department of Agriculture’s running tally of farm and food impacts from the Drought of 2012: http://www.ers.usda.gov/newsroom/us-drought-2012-farm-and-food-impacts.aspx