Incremental changes on the U.S. Drought Monitor map showed drought receding but intensifying in the week that ended Dec. 4. As a powerful, slow-moving storm brought rains to the West, the area of the country in moderate drought or worse shrank, but elsewhere, the area in severe, exceptional or extreme drought grew.
The map showed 52.23 percent of the country in moderate drought or worse, down from 52.44 percent the week before; 35.32 percent in severe drought or worse, an increase from 34.75 percent a week earlier; 17.25 percent in extreme drought or worse, up from 16.83 percent the week before; and 5.43 percent in exceptional drought, up from 5.34 percent the preceding week.
Brad Rippey, a meteorologist and U.S. Drought Monitor author in the U.S. Department of Agriculture’s Office of the Chief Economist, noted that winter wheat conditions are the worst on record for this time of year since 1986, when the data were first collected. Rippey said USDA analysis shows that the proportion of the U.S. hay crop currently in drought is 65 percent, up 5 percentage points from Nov. 13; cattle in drought is 73 percent, up 4 points from Nov. 13; and winter wheat in drought is 65 percent, up from 63 percent in mid-November.
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 morning.
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. The percent area of the U.S. in moderate to extreme drought since 1895 is online: http://www1.ncdc.noaa.gov/pub/data/cmb/sotc/drought/2012/11/uspctarea-wetdry-mod.txt
U.S. Drought Monitor map and narrative summary: http://droughtmonitor.unl.edu
National Climatic Data Center’s State of the Climate Drought Summary: http://www.ncdc.noaa.gov/sotc/drought/
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
-- Kelly Helm Smith, National Drought Mitigation Center