Drought expanded slightly and intensified across the western United States, where record-breaking heat compounded dryness in the week that ended July 2, according to the U.S. Drought Monitor.
All levels of drought increased fractionally in the past week. The area of the contiguous 48 states in moderate drought or worse increased to 44.06 percent from 43.84 percent a week earlier.
“In the west, localized showers in northern California were not sufficient to ease the region’s developing drought, while intense, record-setting heat across the rest of the western U.S. exacerbated drought and maintained or heightened the risk of wildfires,” said Eric Luebehusen, meteorologist in the U.S. Department of Agriculture’s Office of the Chief Economist.
In Arizona, where the Yarnell Hill wildfire claimed the lives of 19 elite firefighters, drought intensified incrementally in the north. This week’s map shows 27.4 percent of the state in extreme drought, compared with 23.48 percent a week ago, and a new area of exceptional drought, the worst category, covering 3.04 percent of the state. The proportion of the state in moderate drought or worse is at 92.46 percent, and 74.35 percent of the state is in severe drought or worse.
Rains brought small reductions in exceptional and extreme drought in New Mexico. Although Texas saw some improvement in the western Panhandle, drought intensified to the south and east in that state.
Nevada has a new area of exceptional drought covering 5.37 percent of the state. Drought also intensified in areas of western Colorado, western Nebraska, southwest Montana, southern Utah, and Alaska.
The remaining patch of moderate drought in Minnesota continued to recede, and a small area of moderate drought in Pennsylvania and West Virginia improved to abnormally dry.
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 U.S. Department of Agriculture, and about 350 drought observers across the country. This week’s author, Matthew Rosencrans, 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/
Seasonal Drought Outlook:
http://www.cpc.ncep.noaa.gov/products/expert_assessment/seasonal_drought.html
-- Kelly Helm Smith, National Drought Mitigation Center