Thursday, April 19, 2018

National Drought Mitigation Center

U.S. Drought Monitor

The U.S. Drought Monitor map provides a summary of drought conditions across the United States and Puerto Rico. Often described as a blend of art and science, the map is updated weekly by combining a variety of data-based drought indices and indicators and local expert input into a single composite drought indicator.

The map denotes four levels of drought intensity (ranging from D1 - D4) and one level of "abnormal dryness" (D0). Also depicted are areas experiencing agricultural (A) or hydrological (H) drought impacts. These impact indicators  help communicate whether short- or long-term precipitation deficits are occurring.

History Behind the Drought Monitor

Prior to launching the U.S. Drought Monitor, drought experts had realized the need for a simple, accurate way to communicate drought conditions to decision makers and the public. The map was designed to show drought intensity on a scale similar to tornadoes and hurricanes, which is already well known to many people. The U.S. Drought Monitor map was unveiled in August 1999 at a White House press conference. The map has been produced every week for over 10 years, and on April 7, 2009 the U.S. Drought Monitor hit a milestone with its 500th map.

Who Uses the Drought Monitor?

The U.S. Drought Monitor sets the standard for communicating location and intensity of drought to a broad audience. The map summarizes and synthesizes information from the local and state level to the national scale, making it the most widely used gauge of drought conditions in the country. Policy makers use it to allocate relief dollars, states use it to trigger drought response measures, and media rely on it. The USDA uses it to distribute millions, even billions, of dollars in drought relief to farmers and ranchers each year, and the Internal Revenue Service also uses it for ranching-related tax determinations.

Current USDM

Current U.S. Drought Monitor

Making the Map

Click to download a brochure on the U.S. Drought Monitor

Authorship of the map rotates to different individuals from different partner agencies in two-week shifts. In addition to consulting a wealth of climate, weather, and water data, authors request information each week from over 270 experts around the country. This expert input helps to ground truth instrument-collected data and computed drought indices that may have seasonal or geographic biases. Although this process is a blend of art and science, authors follow an agreed upon ranking system and methodology (learn more). This unique process of corroborating data with observations of drought conditions and impacts from around the country makes the U.S. Drought Monitor unlike any other drought monitoring tool.

The map is produced in partnership with numerous agencies including NOAA, including the Climate Prediction Center, the National Climatic Data Center, and the Western Regional Climate Center; the U.S. Department of Agriculture’s Office of the Chief Economist, including the Joint Agricultural Weather Facility and the World Agricultural Outlook Board; and the National Drought Mitigation Center. Support for the U.S. Drought Monitor is provided on a voluntary basis through in-kind contributions of time and expertise. There is no devoted funding or budget for this process. 

The National Drought Mitigation Center | University of Nebraska-Lincoln
3310 Holdrege Street | P.O. Box 830988 | Lincoln, NE 68583–0988
phone: (402) 472–6707 | fax: (402) 472–2946 | Contact Us | Web Policy

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Copyright 2018 National Drought Mitigation Center