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We use machine learning models to forecast streamflow drought by training them on 20- and 40-year periods of past streamflow, weather, and watershed data. For a summary of our methods and how we evaluate the models, see:
Publication summarizing modeling methods and performance.
Interactive guide showing how drought models work.
Model input data, including daily weather, snow, soil moisture, and meteorological forecast, is summarized in our ScienceBase Catalog dataset.
To download data on past streamflow percentiles and droughts, please refer to this recent USGS article in Water Resource Research. Weekly streamflow drought observations, along with meteorological data and other factors used in forecasting models can be found at: https://doi.org/10.5066/P1X5VH96. In addition, the daily streamflow drought forecasts can be downloaded in parquet format from the River...
Hydrological drought happens when there is unusually low flow in rivers and streams, as well as low levels in lakes, reservoirs, and groundwater. It usually follows meteorological drought, which occurs first when a lack of rainfall over a long period leads to a water shortage. Meteorological drought can be tracked using the Standardized Precipitation Index (SPI) or the Standardized Precipitation...
When watersheds have been modified due to human activities, it can be complex to characterize hydrological drought using streamflow percentiles. For example, in areas downstream of dams, streamflow that falls below normal percentiles may reflect drought in systems with irrigation and water supply reservoirs that store water from year to year. However, reservoirs are often managed together...
The beginning of a drought is difficult to determine. Several weeks, months, or even years might pass before people know that a drought is occurring. The end of a drought can occur as gradually as it began. The first evidence of drought is usually seen in records of rainfall. Within a short period of time, the amount of moisture in soils can begin to decrease. The effects of a drought on flow in...
Rainfall in any form will provide some drought relief. A good analogy might be how medicine and illness relate to each other. A single dose of medicine can alleviate symptoms of illness, but it usually takes a sustained program of medication to cure an illness. Likewise, a single rainstorm will not break the drought, but it might provide temporary relief. A light to moderate shower will probably...
River DroughtCast is a new machine learning system that predicts streamflow droughts — specifically “streamflow” droughts when rivers and streams drop to unusually low levels— up to 90 days in advance. Each prediction comes with uncertainty information to help users understand the confidence level of the forecast.
River DroughtCast is a new machine learning system that predicts streamflow droughts — specifically “streamflow” droughts when rivers and streams drop to unusually low levels— up to 90 days in advance. Each prediction comes with uncertainty information to help users understand the confidence level of the forecast.
River DroughtCast delivers current streamflow drought conditions and weekly forecasts of streamflow drought at select streamgages with long-term, complete records across the lower 48 states (the conterminous U.S., or CONUS).
River DroughtCast delivers current streamflow drought conditions and weekly forecasts of streamflow drought at select streamgages with long-term, complete records across the lower 48 states (the conterminous U.S., or CONUS).
Wild River at Gilead, Maine, experienced low water levels during a drought event in the summer of 2025.
Wild River at Gilead, Maine, experienced low water levels during a drought event in the summer of 2025.
Stream in Glacier National Park experience severe streamflow drought. The rocks that are normally at the bottom of the river are dry.
Stream in Glacier National Park experience severe streamflow drought. The rocks that are normally at the bottom of the river are dry.
Natural resource managers face increasing challenges in dealing with drought. As competition for water increases between its various uses (water supply, energy demands, ecological services, recreation, and other environmental and ecological needs), our ability to forecast the onset and termination of drought becomes ever more important.
Natural resource managers face increasing challenges in dealing with drought. As competition for water increases between its various uses (water supply, energy demands, ecological services, recreation, and other environmental and ecological needs), our ability to forecast the onset and termination of drought becomes ever more important.
View looking up-stream toward Carraizo Dam in Loiza, Puerto Rico, under drought conditions.
View looking up-stream toward Carraizo Dam in Loiza, Puerto Rico, under drought conditions.
To download data on past streamflow percentiles and droughts, please refer to this recent USGS article in Water Resource Research. Weekly streamflow drought observations, along with meteorological data and other factors used in forecasting models can be found at: https://doi.org/10.5066/P1X5VH96. In addition, the daily streamflow drought forecasts can be downloaded in parquet format from the River...
Hydrological drought happens when there is unusually low flow in rivers and streams, as well as low levels in lakes, reservoirs, and groundwater. It usually follows meteorological drought, which occurs first when a lack of rainfall over a long period leads to a water shortage. Meteorological drought can be tracked using the Standardized Precipitation Index (SPI) or the Standardized Precipitation...
When watersheds have been modified due to human activities, it can be complex to characterize hydrological drought using streamflow percentiles. For example, in areas downstream of dams, streamflow that falls below normal percentiles may reflect drought in systems with irrigation and water supply reservoirs that store water from year to year. However, reservoirs are often managed together...
The beginning of a drought is difficult to determine. Several weeks, months, or even years might pass before people know that a drought is occurring. The end of a drought can occur as gradually as it began. The first evidence of drought is usually seen in records of rainfall. Within a short period of time, the amount of moisture in soils can begin to decrease. The effects of a drought on flow in...
Rainfall in any form will provide some drought relief. A good analogy might be how medicine and illness relate to each other. A single dose of medicine can alleviate symptoms of illness, but it usually takes a sustained program of medication to cure an illness. Likewise, a single rainstorm will not break the drought, but it might provide temporary relief. A light to moderate shower will probably...
River DroughtCast is a new machine learning system that predicts streamflow droughts — specifically “streamflow” droughts when rivers and streams drop to unusually low levels— up to 90 days in advance. Each prediction comes with uncertainty information to help users understand the confidence level of the forecast.
River DroughtCast is a new machine learning system that predicts streamflow droughts — specifically “streamflow” droughts when rivers and streams drop to unusually low levels— up to 90 days in advance. Each prediction comes with uncertainty information to help users understand the confidence level of the forecast.
River DroughtCast delivers current streamflow drought conditions and weekly forecasts of streamflow drought at select streamgages with long-term, complete records across the lower 48 states (the conterminous U.S., or CONUS).
River DroughtCast delivers current streamflow drought conditions and weekly forecasts of streamflow drought at select streamgages with long-term, complete records across the lower 48 states (the conterminous U.S., or CONUS).
Wild River at Gilead, Maine, experienced low water levels during a drought event in the summer of 2025.
Wild River at Gilead, Maine, experienced low water levels during a drought event in the summer of 2025.
Stream in Glacier National Park experience severe streamflow drought. The rocks that are normally at the bottom of the river are dry.
Stream in Glacier National Park experience severe streamflow drought. The rocks that are normally at the bottom of the river are dry.
Natural resource managers face increasing challenges in dealing with drought. As competition for water increases between its various uses (water supply, energy demands, ecological services, recreation, and other environmental and ecological needs), our ability to forecast the onset and termination of drought becomes ever more important.
Natural resource managers face increasing challenges in dealing with drought. As competition for water increases between its various uses (water supply, energy demands, ecological services, recreation, and other environmental and ecological needs), our ability to forecast the onset and termination of drought becomes ever more important.
View looking up-stream toward Carraizo Dam in Loiza, Puerto Rico, under drought conditions.
View looking up-stream toward Carraizo Dam in Loiza, Puerto Rico, under drought conditions.