Monitoring Drought in the United States: Status and Trends - Monitoring and Predicting Agricultural Drought: A Global Study - page 126

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U .S. Drought Monitor

The U.S. Drought Monitor was developed through a partnership between
the National Drought Mitigation Center at University of Nebraska, the
National Centers for Environmental Prediction/Climate Prediction Center
(NCEP/CPC) of NOAA, and the USDA's Joint Agricultural Weather Fa-
cility (USDA/JAWF). The National Drought Policy Act, passed by the U.S.
Congress in the summer of 1998, and the subsequent formation of the
National Drought Policy Commission (NDPC) and its working groups in
1999 provided additional momentum to improve drought monitoring ef-
forts in the United States. A working group on monitoring and prediction
formed by the NDPC during spring 1999 provided additional opportuni-
ties for interactions with a larger group of climatologists throughout the
country on drought monitoring issues. The group also helped to form the
template for early versions of the U.S. Drought Monitor, first released on an
experimental basis on May 20, 1999, as a biweekly product. The Drought
Monitor became an operational product in August 1999 when it was of-
ficially released at a joint White House press conference conducted by the
Department of Commerce and USDA.
The Drought Monitor is maintained on the Web site of the NDMC
( http://drought.unl.edu/monitor/ monitor.html). It consists of a map
showing which parts of the United States are suffering from various degrees
of drought (figure 9.2). The map also accompanies text that describes the
drought's current impacts, future threats, and prospects for improvement.
The Drought Monitor is derived from several key parameters and ancillary
indicators (e.g., fire potential, pasture and range conditions) from different
agencies. The six key parameters making up the scheme at this writing
are the PDSI, the Climate Prediction Center's Soil Moisture Model (per-
centiles), the U.S. Geological Survey's daily streamflow (percentiles), per-
centage of normal precipitation, SPI, and a remotely sensed satellite vege-
tation health index. Table 9.2 illustrates the drought severity classification
system currently used to prepare the map.
The authors of the Drought Monitor rely on different agencies for the
inputs required to create the map. The initial draft of the map is produced
on Monday and distributed via e-mail to more than 150 climate, water
supply, and agricultural specialists throughout the country. These persons
are asked to review the map and provide comments. These regional experts
often have a better understanding of local situations because of their direct
contacts with agricultural, water, and natural resources managers. Based
on the comments from these reviewers, the map is revised and a second
draft is distributed. The final map is completed by Wednesday night and
placed on the Web site at 0730 h (Central Standard Time) each Thursday
morning. Previous maps are archived, and users can also see an animation
of the past 6- and 12-week periods to better visualize the changing spatial
extent and severity of drought conditions across the country. The Drought
Monitor map for May 21, 2002, provides an example (figure 9.2).

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