Known for its glowing swaths of yellow, orange and red, the U.S. Drought Monitor has warned farmers, residents and officials throughout the nation of impending water scarcity every week since 1999. Known for its glowing swaths of yellow, orange and red, the U.S. Drought Monitor has warned farmers, residents and officials throughout the nation of impending water scarcity every week since 1999. Earth Sciences Environment Phys.org – latest science and technology news stories