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United States Department of Agriculture

Agricultural Research Service

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Location: Hydrology and Remote Sensing Laboratory

2013 Annual Report

1a. Objectives (from AD-416):
To bring an existing drought and ET remote sensing model (ALEXI) into operational function within NOAA-NESDIS, and to deliver products to NAA-CPC, the National Drought Mitigation Center (NDMC), and the NIDIS Drought Portal for use in operational drought monitoring within the U.S. and North America.

1b. Approach (from AD-416):
The ALEXI model automated infrastructure will be connected to standard NOAA input products and conformed to run on a computing platform at NESDIS. An archive of model output will be generated for 2000-present over the contiguous U.S., and for 2007-present for a domain covering North America. Monthly anomalies in an Evaporative Stress Index (ESI), ET and soil moisture from the model will be compared with standard drought indices, with soil moisture observations, and with known drought events to ascertain robustness and model sensitivity. After ESI has been evaluated, it will be used to verify drought forecasts generated by CPC for the North American Drought Briefing. ALEXI drought products will be delivered in real-time to CPC and to NDMC for operational monitoring, and they will also be distributed through the U.S. Drought Portal.

3. Progress Report:
Realtime data production has been automated with the Atmosphere-Land Exchange Inverse Contiguous U.S. (ALEXI CONUS) processing infrastructure. A web-based interface ( for data distribution and visualization has been refined in response to user feedback. A derived set of Rapid Change Indices (RCI) have been developed to highlight regions in the U.S. where soil moisture and vegetation health seem to be rapidly declining, and the skill of these RCIs for anticipating degradation in U.S. Drought Monitor drought severity class has been quantitatively assessed. The CONUS Evaporative Stress Index (ESI) data are distributed to National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) for use in the North American Drought Briefing, and are also served through the National Integrated Drought Information System (NIDIS) drought portal at

4. Accomplishments

Last Modified: 05/23/2017
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