The Federal Aviation Administration (FAA) Aviation Weather Research Program has sponsored research and development activities for the improvement of in-flight icing detection and forecasting. As a result of these efforts, the National Center for Atmospheric Research has developed the Integrated Icing Forecast Algorithm (IIFA). IIFA uses Rapid Update Cycle (RUC) generated relative humidity, predicted precipitation, and supercooled liquid water from the RUC microphysics package to identify areas of expected in-flight icing. IIFA output is displayed as horizontal plan views of Icing Potential and Supercooled Large Droplet (SLD) Potential at flight levels ranging from 3,000 to 30,000 feet at 3,000-foot intervals. Plan views are also available for the tops and bases of Icing Potential, SLD Potential, and clouds. IIFA output is available for 3-, 6-, 9-, and 12-hour forecasts.

In support of IIFA's development in 2002, the FAA William J. Hughes Technical Center Weather Branch (ACT-320) is performing a user assessment of the IIFA. The assessment is examining the utility and benefit of IIFA to regional airline dispatchers and pilots. As part of the assessment, ACT-320 meteorologists are reviewing IIFA on a daily basis identifying trends in model output and performance. In addition, the user feedback is providing indication of conditions where IIFA performs well, along with conditions where it does not perform as well. Any trends identified will be further examined in regards to the underlying meteorological conditions. Results of the assessment will be used in making enhancements to IIFA and will be used in considerations of IIFA becoming an operational product.