High ice water content conditions around darwin: Frequency of occurrence and duration as estimated by a nowcasting model

Areas of high ice water content (HIWC) pose a threat to aviation as they appear to be the cause of over 150 engine power-loss and damage events since the 1990s. The Algorithm for the Prediction of HIWC Areas (ALPHA) was developed by the HIWC Product Development Team at NCAR and deployed in three field campaigns, which in turn provided the first set of research quality observations of HIWC conditions. These data have been used to improve the skill of ALPHA’s diagnostic ability. With the goal of eventually developing a HIWC forecasting tool, this study analyzed two months of ALPHA diagnoses over northern Australia during the 2014 monsoon season. Using the Thunderstorm Identification Tracking Analysis and Nowcasting tool (TITAN), individual HIWC features were identified and tracked over time, allowing for a characterization of average feature size, HIWC potential, and feature duration. Results found considerable regional differences in the Darwin area in HIWC occurrence, potential, and feature size. Large scale results are also presented, showing that HIWC potential, feature area, and feature duration are related to one another and could potentially be used to predict changes in HIWC conditions.