Water Supply Forecasts
Key to Successful Water Management
People who live in the semi-arid western United States often refer to water as the lifeblood of their land. And there’s a delicate balance between water supply and snow fall. Nearly all water used to supply cities, farms, and industry in the West comes from melting snow in the high mountains.
NOAA’s vigilance in monitoring and understanding mountain snow pack helps the agency forecast the availability of water resources for the upcoming year. Managers of this precious resource rely on NOAA forecasts when making decisions about water allocation and management.
NOAA leads the National Integrated Drought Information System, which is a collaborative effort between federal, state, and local governments tasked to ensure a high level of drought-related information sharing and awareness. The National Integrated Drought Information System maintains a Web portal where water management officials access current drought status, forecasts, effects and planning information.
Managing Water Supplies in Drought
As shown by the U.S. Drought Monitor, drought occurred in every Western state last year. And drought conditions in the West will continue to be a major concern in the future. Increasing population in Western cities has further stressed water management and has added concern to the already dry region.
Before the snow melts each spring, NOAA’s National Weather Service River Forecast Centers project how much water the melting snow will supply to hundreds of river basins in the western United States. Coordinating with many other agencies, NOAA scientists generate water supply forecasts monthly between December and June for the western United States.
Water supply forecasters use mathematical models of the mountain snow pack, water flow, soil infiltration, evaporation, and precipitation to develop forecasts. These models are based on scientific understanding of snow and the land surface coupled with forecasts for weather and climate.
Forecasters create detailed water supply forecasts using observations of precipitation, snow totals, temperatures, and stream flow from networks operated by NOAA, the U.S. Geological Survey, the Natural Resources Conservation Service, and state and local agencies.
More Effective Resource Management
With this combined information, NOAA scientists provide forecasts that are essential for helping water resource managers keep water flowing in homes and communities throughout the western United States.
NOAA scientists post seasonal water supply forecasts on their Water Resource Forecasts Web site. This Web site not only gives residents in the western United States a glimpse of the expected water supply in their area, but it also houses useful information to help water resource managers do their job.
A large number of federal and state agencies and interest groups are responsible for managing the physical, legal, and economic constraints of the water supply. The starting point for these efforts begins with an accurate water supply forecast from NOAA’s National Weather Service. 