Drought increased in all categories during the week that ended Nov. 27, with the largest increases in the Southeast, according to the U.S. Drought Monitor map.
The map showed 52.44 percent of the country in moderate drought or worse, compared with 50.30 percent the week before; 34.75 percent in severe drought or worse, compared with 31.67 percent a week earlier; 16.83 percent in extreme drought or worse, compared with 15.93 percent the week before; and 5.34 percent in exceptional drought, up from 5.23 percent the preceding week. The portion of the United States in moderate drought or worse peaked in 2012 on Sept. 25 at 54.77 percent.
In the Southeast, the area in moderate drought or worse increased to 46.75 percent this week from 30.76 percent last week, with a smaller increase in the area in severe drought.
“Rainfall over the past two months has totaled less than 50 percent of normal (locally less than 25 percent of normal) from northern Florida and southern Alabama northeastward across much of Georgia into central portions of the Carolinas,” wrote U.S. Drought Monitor author Eric Luebehusen, U.S. Department of Agriculture Office of the Chief Economist, in narrative accompanying the map. “Streamflows across much of the Southeast — excluding central and southern Florida — are in the fifth percentile or lower. Further illustrating the drought’s increasing impacts, pastures rated poor to very poor in Georgia have jumped from 29 to 53 percent over the past month (as of November 25), while winter wheat emergence in North Carolina stood at 45 percent as of November 25, 13 points behind last year and 7 percentage points behind the five-year average.”
The drought entrenched over the Plains showed mainly small changes. Conditions in South Dakota eased slightly, although in Oklahoma, extreme drought increased to 90.5 percent from 71.86 percent.
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/2012/10/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