Incremental changes in the Southeast, South and West led to another slight reduction in the area in moderate drought or worse, while drought intensified in some of the hardest-hit areas, on the Dec. 18 U.S. Drought Monitor.
“Over the next five days (December 19-23) the weather pattern should stay active, with multiple storm systems impacting the country,” wrote Brian Fuchs, this week’s U.S. Drought Monitor author, in narrative accompanying the map. “A vigorous system will be moving out of the Plains and into the Midwest and Great Lakes region and finally into New England over the next five days.”
The map showed 51.74 percent of the country in moderate drought or worse, down from 51.82 percent the week before; 35.56 percent in severe drought or worse, down from 35.62 percent a week earlier; 18.12 percent in extreme drought or worse, up from 17.62 percent the week before; and 5.54 percent in exceptional drought, up from 5.43 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 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