Data Source Description
Sources: UC Merced, Climate Engine
The Long-Term Multi-Indicator Drought Index (MIDI) is an experimental blended product. It looks at current drought conditions across the U.S. by integrating several key long-term drought indices into one objective, computer-generated map. MIDI data were from Climate Engine were available in raster format.
This product is based on methodology from the NOAA National Weather Service’s Climate Prediction Center. The short-term and long-term MIDIs are created using the Climate Engine tool, and apply Climate Prediction Center weighting ratios to the high-resolution gridMET gridded research dataset. The data are updated every 5 days, with a delay of 4 to 5 days to allow for data collection and quality control.
The long-term MIDI combines the Palmer Drought Severity Index (PDSI), Palmer Z-Index, 180-day Standardized Precipitation Index (SPI), 1-year SPI, 2-year SPI, and 5-year SPI to approximate drought impacts from changes in precipitation and moisture over a long-term timeframe. This product uses the same percentile category ranges as the U.S. Drought Monitor.
This product is an example of current NIDIS-funded research. Learn more.
* Currently, data are only available for the contiguous U.S.