NCRFC Drought Information
- Palmer Drought Index
- Crop Moisture Index
- Standardized Precipitation Index
- U.S. Drought Assessment
- NDMC Drought Monitor Page
The Palmer Drought Index is updated weekly by the Climate Prediction Center. It is based on rainfall, temperature and historic data, and is computed based on a complex formula devised by W.C. Palmer in 1965.
The Crop Moisture Index is updated weekly by the Climate Prediction Center. It is a derivative of the Palmer Drought Index, designed to reflect quickly changing soil moisture conditions.
The Standardized Precipitation Index (SPI) is a relatively new drought index, based only on precipitation. The SPI can be calculated for a variety of time scales. This flexibility allows the SPI to be useful in both short-term agricultural and long-term hydrological applications.
Issued every Thursday by the CPC along with the U.S. Department of Agriculture, and the National Drought Mitigation Center in Lincoln, Nebraska. These assessments review national drought conditions and indicate potential impacts for various economic sectors, such as agriculture and forestry.
The Drought Monitor was introduced as an operational weekly product in 1999 to provide an overview of conditions averaged across a broad array of time scales and impact indicators, leaning toward those that seem most relevant to observed impacts.
