Verification of in-flight icing severity forecasts and diagnoses over Europe using ADWICE against PIREPS

Icing conditions cannot be explicitly predicted because they involve specific and rare occurrences of cloud microphysical parameters that are presently not accounted for in weather forecast models. Empirical techniques, such as the German post-processing model ADWICE (Advanced Diagnosis and Warning system for aircraft Icing Environments), operated by Deutscher Wetterdienst (DWD), are therefore required to diagnose and forecast icing conditions for aviation. This presentation shows a long-term evaluation of in-flight icing severity diagnoses and forecasts produced for Europe using the ADWICE system. Forecasting of icing conditions relies on predicted meteorological fields from the DWD-operated COSMO-EU model (7 km spatial resolution, T+78h range). The ADWICE diagnosis is additionally based on radar information, SYNOP and METAR observations. The COSMO-EU 7 km model was run over Europe to produce 2 years of NWP data as input for the ADWICE algorithms. The generated icing fields were then verified using nearly 1500 pilot reports (PIREPS) over Europe between January 2010 and March 2012 as “truth” data. Subsequently, ADWICE forecasts were verified over the whole time period and analyzed with respect to seasonal, regional and altitude variations. The ADWICE products show good skills in both, spatial and temporal resolution.