The Sept. 25 U.S. Drought Monitor showed intensification of drought over the upper Midwest and Plains, and in Texas and Georgia. It also registered improvements, notably in Illinois.
Statistics released with the map showed that 54.77 percent of the country was in moderate drought or worse, the largest percentage so far recorded at that level, up slightly from 54.25 percent the week before. The map showed 35.24 percent in severe drought or worse, down slightly from 34.35 percent a week earlier; 17.97 percent in extreme drought or worse, a slight increase from 17.35 percent the week before; and 5.12 percent in exceptional drought, compared with 4.98 percent the preceding week.
Minnesota saw one of the most dramatic increases, with 77.45 percent of the state in moderate or worse drought, up from 64.11 percent the week before; 35.36 percent in severe drought, up from 28.17 percent the week before; and 18.51 percent in extreme drought, up from 4.32 percent the week before.
Wisconsin, the Dakotas, Nebraska, Texas and Georgia all showed intensification in at least one category of drought.
Improvement in Illinois reduced the area of the state in moderate or worse drought to 82.37 percent, down from 92.66 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