Products of the Advanced Hydrologic Prediction Service (AHPS) were first tested in the Des Moines river basin after the 1993 floods. Severe floods in 1997 gave an impetus for faster expansion. Nationwide implementation is currently underway. At the moment, AHPS is available at over 2,500 locations across the USA. AHPS is a component of the Climate, Water and Weather Services that are provided by the National Weather Service (NWS). The National Weather Service is part of the National Oceanic and Atmospheric Administration (NOAA). The goal of AHPS is to enable its users to  make more informed decisions about risk based policies and actions to mitigate the dangers posed by floods and droughts.

For this purpose, AHPS provides online maps, hydrographs, RSS feeds and shapefiles/KMZ files. They include forecast information such as flood levels, peak and crest times; probability of river exceeding minor, moderate or major flooding, the probability of a certain level, volume and flow of water at specific points on the river during 90-day periods; and flood information for major roads, railways, landmarks etc. surrounding a forecast point. In addition, information about potential droughts can be provided as well.

In order to provide this information, the Hydrometeorological Automated Data System (HADS) acquires and processes raw hydrological and meteorological observational data from ground-based Data Collection Platforms (DCPs). DCPs are owned and operated by federal, state, and local agencies. The information is then sent to the Weather Forecast Offices (WFOs) and River Forecast Centers (RFCs) which in turn use hydrological models to make the information available on the AHPS website. Data sources of the NWS include super computers, automated gauges, geostationary (GOES) satellites, Doppler radars, weather observation stations and a computer and communications system.

Main users are emergency management officials, economic managers, government agencies, private institutions and the general public.

References:

AHPS Website (http://water.weather.gov/ahps/index.php, accessed on March 28, 2012)

V. Grasso and A. Singh, UNEP (Dec 2011, forthcoming): Early Warning Systems:
State-of-Art Analysis and Future Directions.