Jennifer Luppens Mahoney, Chief

Verification is key to providing information for improving weather forecasts. As part of FSL's involvement with the FAA Aviation Weather Research Program, the Forecast Verification Branch (FVB) develops verification techniques and tools that allow forecasters, researchers, developers and program leaders to generate and display statistical information in near real time using the Real-Time Verification System (RTVS).

As part of the FSL strategic plan, the FVB strives to maintain a strong verification program by working closely with other agencies, such as the NCAR/RAP, NWS, and NCEP. The technology developed through these close interactions can benefit all agencies by building and strengthening the verification programs.

The Real-Time Verification System (RTVS)

RTVS is being developed by scientists at NOAA/FSL, in collaboration with scientists from the National Center for Atmospheric Research (NCAR) and the National Weather Service Aviation Weather Center (AWC), as a tool for assessing the quality of weather forecasts. RTVS has been designed to provide a statistical baseline for weather forecasts and model-based guidance products, support real-time forecast operations, model-based algorithm development, and case study assessments.

To this end, RTVS was designed to ingest weather forecasts and observations in near real time and store the relevant information in a relational database management system (RDBMS). A flexible easy-to-use Web-based graphical user interface allows users quick and easy access to the data stored in the RDBMS. Users can compare various forecast lengths and issue times, over a user-defined time period and geographical area, for a variety of forecast models and algorithms.

The RTVS has become an integral part of the Federal Aviation Administration Aviation Weather Research Program (link) by providing a mechanism for monitoring and tracking the improvements of AWRP-sponsored forecast products. RTVS runs operationally at the AWC providing feedback directly to forecasters and managers in near real time.

Verification Methods

The FVB is an active participant, in collaboration with NCAR, in developing and testing state-of-the-art verification methods, with an emphasis mainly on aviation and precipitation forecast problems. New techniques have been developed for convection, icing, turbulence, ceiling and visibility, and precipitation. Many of these techniques are applied to aviation forecasts that have been deemed "unverifiable." Nevertheless, the development and implementation of these verification methods are leading to a better understanding and improvement in the aviation forecasts.

During Fiscal Year 2001, an end-to-end RTVS was delivered to the AWC. Three modules were implemented at AWC, including real-time processing of the AWC icing and turbulence forecast/observation pairs using AWC decoded data, storage and access of the data through the RDBMS, and display through a newly developed Web-based graphical user interface.

Extensive verification activities supporting the transition of the National Convective Weather Forecast (NCWF) and the Integrated Icing Diagnosis Algorithm (IIDA) were completed by the FVB. The results were used in the FAA/NWS decision process of whether to transfer the algorithm from an experimental phase to a fully operational weather product that would be supported by NWS. The verification reports are available in the Publications section.

The FVB was also involved in modifying the RTVS and generating statistics for three real-time objective intercomparison exercises, including turbulence, convection, and icing. The turbulence exercise was held from 8 February - 31 March 2001 where fourteen algorithms over five domains at two different altitude bands were compared to the operational turbulence forecast (i.e., AIRMETs).

Staff of the FVB will continue with real-time objective intercomparison exercises for turbulence, convection, and ceiling and visibility. In part, the RTVS will support the Convective Weather Demonstration and the International H20 project during the summer of 2002. Extensive evaluation of the Integrated Turbulence Forecast Algorithm (ITFA) will be completed and provided to the FAA/NWS Aviation Weather Technology Transfer Board for its consideration to operational status within the NWS. The RTVS will be enhanced to include advanced diagnostic verification techniques that will allow users the ability to partition the forecasting errors. New verification tools will be developed allowing forecasters the ability to investigate and interrogate the raw forecasts and observations.