NIDIS Intermountain West
Drought Early Warning System
June 27, 2017
April 3, 2017
The Composite Drought Evaluator eXperiment (CoDEX) is an experimental product, produced by the Colorado Climate Center,
that is designed to work as an indicator of predominant conditions within certain regions of the Intermountain West.
It is developed by assessing U.S. Drought Monitor described drought categories for each individual variable. Variables include
precipitation, soil moisture, streamflows, vegetation, evaporative demand, and drought impacts. The composite of
drought categories for all these variables are combined to represent overall conditions for each HUC4 region.
A region highlighted in yellow shows regions that are currently in a D0-D4 drought category, and the composite
agrees with those conditions. Regions highlighted in orange should be closely monitored for possible degradations,
and regions highlighted in green should be assessed for possible improvements.
This product is experimental and is for informational purposes only. It does not dictate what the U.S.
Drought Monitor may look like in the future, and will not be a major source of information for the NIDIS
Intermountain West DEWS webinars either.