West-Wide Drought Forecasting System:
A Scientific Foundation for NIDIS

Drought is the costliest natural hazard in the U.S., averaging $6-8 billion in damages annually. Forecasts and real-time assessments of drought offer the potential to mitigate drought impacts. However, current drought monitoring systems for the western U.S. lack a predictive component for specific hydrologic indicators. Further, given that hydrologic impacts account for most drought losses, USGS data are essential to making drought forecasts useful.

We are developing a drought forecast and nowcast system for the western U.S., which will serve as a scientific framework for prediction and assessment of agricultural (soil moisture) and hydrologic (streamflow) drought in the region. This work, in collaboration with USGS personnel, will provide early warning capabilities and science-based indicators that are critical for the National Integrated Drought Information System (NIDIS), an effort of the Western Governors' Association (WGA), the National Drought Mitigation Center (NDMC), NOAA, the USGS, and other agencies. Our work will also contribute to the U.S. Drought Monitor, which currently uses our National Surface Water Monitor, by incorporating USGS data into methods to characterize and forecast drought conditions, persistence, and recovery. Further, we are working directly with water managers in selected states in the region (Washington, California, and others) to apply this forecast system to water resources decisions.

Our specific objectives are to (1) implement a version of the Variable Infiltration Capacity (VIC) model that represents near-surface groundwater directly and thus can incorporate USGS well level data; (2) assimilate observations not presently used in the West-Wide system that are highly relevant to drought, such as USGS streamflow data from HCDN and similar stations, soil moisture information, and USGS well data; (3) produce probabilistic forecasts of drought persistence and recovery using ensemble prediction methods that incorporate climate forecasts out to one year; and (4) work with the WGA, the NDMC, and other users, such as state water agencies, to incorporate the resulting drought forecasts and nowcasts into drought information systems and water management decisions.

Funded by the U.S. Geological Survey (USGS)

Anne C. Steinemann, PI, with Dennis P. Lettenmaier and Andrew W. Wood, Co-PIs

 

 

 

 

 

 

Above: the Elwha River. USGS photo by Dallas Childers.