In-Flight Icing
This Current Icing Product was developed at NCAR as part of the FAA’s Aviation Weather Research Program. Colors depict expected icing severity; the red cross-hatching shows regions of supercooled large drop icing, which pose an extra hazard for many aircraft.
National Transportation Safety Board records indicate that in-flight icing causes more than 25 accidents annually, with over half of these resulting in fatalities and damaged aircraft. The cost of injuries, fatalities and aircraft damage is estimated to be $100M annually. The RAL In-Flight Icing Program addresses this problem by producing improved operationally -available, high-resolution, accurate diagnoses and forecasts of aircraft icing conditions. This work is funded by the FAA's Aviation Weather Research Program.
FY06 Accomplishments:
An initial study using NASA’s advanced satellite products to further improve the severity product was very encouraging in identifying areas of hazardous icing. Additionally, freezing drizzle detection using NEXRAD data looks very feasible, and RAL scientists are now in the process of determining where and how to implement the detection algorithm. Microphysical parameterizations are continually being upgraded and implemented in developmental versions of the Weather Research and Forecast (WRF) model; these have made noticeable improvements in cloud condensate and precipitation forecasts. Previous upgrades have been incorporated in the NCEP Rapid Update Cycle (RUC) model. RAL also will prepare recommendations to the FAA and NWS concerning the benefits to the icing community of continued support of TAMDAR data acquisition.
Current Icing Product with and without NASA cloud phase and liquid water path input. Inclusion of this high-resolution satellite-derived information has the potential for improved resolution and accuracy. Circles indicate areas where greatest improvements are noted in this comparison.
Technical development of the Current Icing Potential product's severity/probability upgrade is nearly complete. The next steps are verification of the new algorithm and code delivery to the Aviation Weather Center for installation and testing.
Plans for FY07
Early in FY07 the new Current Icing Severity product is expected to reach full operational status. This means hourly graphics depicting expected icing severity and probability of encounter will be produced at the NWS' Aviation Weather Center. The product will be accepted as supplementary guidance without the current restrictions of use to forecasters only. The forecast version of this product should be accepted for experimental use in March 2007. Work will also continue to upgrade other icing products through the inclusion of new data from the NSSL 3D radar mosaic, NASA Langley advanced satellite products, and the in situ TAMDAR sensor data. Research activities will focus on determination of scales of liquid water in the atmosphere, characterization of size distributions of ice crystals and water drops, improvements in WRF model microphysics, and summarizing icing climatology around the globe