Overview

The Standardized Precipitation Index (SPI) is a widely used drought index that has several strengths including the ability to calculate precipitation anomalies at different timescales and the ability to interpret SPI units (standard deviations) in probabilistic terms (click here for more info on the SPI).

This tool was created to explore SPI values at specific locations by using a gridded climate dataset (PRISM Climate) to estimate local precipitation time series. Data are accessed through the Applied Climate Information Web Service and analyzed and plotted using several R based packages. This version of the tool includes the calculation of the Standardized Precipitation-Evapotranspiration Index (SPEI). More info on the SPEI can be found here.

Managing Organizations

Climate Adaptation Partnerships (CAP) Network

The Climate Adaptation Partnerships (CAP) network, formerly known as the Regional Integrated Sciences and Assessments (RISA) Program, comprises regional teams who conduct collaborative research on weather and climate-related issues of concern to decision makers and community planners at state and local levels. CAP is funded by the National Oceanic and Atmospheric Administration’s Climate Program Office.

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