A late growing season drought intensified in Iowa and neighboring states in the week that ended Sept. 4 on the U.S. Drought Monitor map.
“After such an ideal start to the growing season, the past two months have been much drier than usual, with temperatures slowly increasing,” said David Miskus, this week’s U.S. Drought Monitor author, in narrative accompanying the map. He noted that:
- Some rain gauges in central Iowa and northern Missouri have recorded precipitation that was only 5 to 25 percent of normal, and as little as a tenth of an inch of rain.
- Iowa recorded its warmest week since July 2012, with highs of 104 degrees Fahrenheit at Des Moines and Fort Madison on Aug. 30.
- This year was Iowa’s seventh driest August in 141 years of records, and it followed the ninth driest July.
- Crop and pasture conditions began to deteriorate rapidly once heat was added to the dryness.
The proportion of Iowa in severe drought increased to 32.07 percent on this week’s map, from 22.4 percent a week earlier, and 63.24 percent of the state is in moderate drought or worse. Small areas of severe drought also showed up in Illinois, Minnesota and Wisconsin this week. Drought also expanded or intensified in Mississippi and Oklahoma and on the Hawaiian island of Maui.
The portion of the U.S. corn production area in drought increased from 45 to 52 percent during the week ending September 3, said Brad Rippey, a meteorologist in the U.S. Department of Agriculture’s Office of the Chief Economist. Soybeans in drought also increased in the last week, from 38 to 42 percent. Corn and soybeans in drought bottomed out in July at 17 and 8 percent, respectively. Meanwhile, hay in drought was unchanged at 39 percent, but cattle in drought increased one percentage point to 53 percent.
“Given that U.S. producers planted an estimated 97.4 million acres of corn and 77.2 million acres of soybeans in 2013, current drought figures suggest that more than 50 million acres (nearly 80,000 square miles) of corn and some 32 million acres (more than 50,000 square miles) of soybeans are presently being affected by drought,” Rippey said. “According to USDA, nearly one-sixth of the U.S. corn (16 percent) and soybeans (15 percent) were rated in very poor to poor condition on September 1. A year ago, near the height of the Drought of 2012, very poor to poor ratings stood at 52 percent of the corn and 37 percent of the soybeans.”
While the Midwest dried out, parts of the Southwest and West benefitted from the monsoon season and rains brought scattered improvements across the country, including a reduction in Alaska’s first-ever severe drought.
Incremental adjustments to the map left the associated statistics nearly unchanged. The proportion of the contiguous United States in moderate drought this week crept up to 50.09 percent from 50.04 percent a week earlier, and all other categories of drought showed small decreases. Rippey noted that the proportion in exceptional drought shrank to 1.25 percent, down 0.07 percentage points from last week to the smallest area since July 17, 2012.
U.S. 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 map is released each Thursday based on data through the previous Tuesday morning.
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 USDA, and about 350 drought observers across the country. Miskus is with NOAA’s Climate Prediction Center.
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. U.S. Drought Monitor data online goes back to January 2000.
http//drought.unl.edu/MonitoringTools/USDroughtMonitor/DroughtMonitorTips.aspx
U.S. Drought Monitor map, statistics and narrative summary: http://droughtmonitor.unl.edu
Drought Impact Reporter: http://droughtreporter.unl.edu
USDA’s weekly “Agriculture in Drought” analysis:
http://www.usda.gov/oce/weather/Drought/AgInDrought.pdf
National Climatic Data Center’s State of the Climate Drought Summary: http://www.ncdc.noaa.gov/sotc/drought/
U.S. Monthly Drought Outlook:
http://www.cpc.ncep.noaa.gov/products/expert_assessment/monthly_drought.html
U.S. Seasonal Drought Outlook:
http://www.cpc.ncep.noaa.gov/products/expert_assessment/seasonal_drought.html
-- Kelly Helm Smith, National Drought Mitigation Center