The footprint of the Drought of 2012 shifted slightly in the seven days that ended Aug. 28, 2012, according to the U.S. Drought Monitor map released today, with Hurricane Isaac bringing hope for rainfall up through the Mississippi Valley later in the week.
“If the hurricane goes inland and continues on its slow path, the opportunity will be there not only for drought-busting rains, but for a transition into flooding,” said Brian Fuchs, a climatologist at the National Drought Mitigation Center at the University of Nebraska-Lincoln and this week’s U.S. Drought Monitor author. “If the forecasted storm track of anywhere from 4 to 7 inches of rain materializes, that could change the landscape of drought in a hurry.”
In fact, it could be problematic. “The rain is going to come too late for many crops,” Fuchs said. “It’ll help with pasture greenup and soil recharge, but with too much there could be problems as harvest starts up.”
This week’s map brought some good news. Fuchs observed that drought eased over Kansas, Oklahoma, Iowa, southeast Nebraska and Illinois, where areas in severe drought replaced some that had been in extreme and exceptional drought.
Extreme drought ebbed in southern Arizona, but grew in western Nevada, in southern and eastern Wyoming and in South Dakota, Fuchs noted. A small patch of exceptional drought emerged in far south Texas, and exceptional drought dipped from Nebraska into the southeast corner of Colorado.
The map confirmed that Florida is now back to normal, after two years of dryness. “Florida is color-free for the first time since June 29, 2010,” Fuchs said.
Statistics released with the map showed 52.63 percent of the country was in moderate drought or worse, nearly unchanged from 52.89 percent the week before. The map showed 35.42 percent in severe drought or worse, compared with 36.83 percent a week earlier; 19.38 percent in extreme drought or worse, compared with 19.24 percent the week before; and 5.05 percent in exceptional drought, compared with 5.27 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
-- Kelly Helm Smith, National Drought Mitigation Center