Icing Hazard Detection with NEXRAD IHL

Icing has been a long standing safety challenge for aviation, particularly for smaller aircraft that fly at lower altitudes. There are a multitude of weather products that estimate the icing hazard based primarily on model data with some supporting surface and radar reflectivity data. The recent upgrade of the NEXRAD radar network to dual-polarization presents an opportunity to create a high quality icing hazards product that is based primarily on direct measurement of the icing conditions. MIT Lincoln Laboratory (MITLL), under the direction of the FAA, has been developing a radar-based (but model-enhanced) Icing Hazard Levels (IHL) product embedded within the NEXRAD product suite. This work was performed in conjunction with the National Severe Storms Laboratory (NSSL), the National Center for Atmospheric Research (NCAR), and the National Weather Service (NWS). The paper details the work performed to investigate and enhance the existing icing-related products within NEXRAD, such as the Melting Layer Detection Algorithm (MLDA), the Hydrometeor Classification Algorithm (HCA), and the less-well-known model data ingest capability. By utilizing these components along with pilot and surface observation reports, MITLL has developed a new icing hazard detection capability that will be deployed as part of the NEXRAD Build14 (late 2013). Finally, continued development will provide extensions of this initial capability to create high quality icing detection products that can be used directly by aviation and/or as input to icing algorithms that utilize datasets external to the NEXRAD.

This work was sponsored by the Federal Aviation Administration under Air Force Contract No. FA8721-05-C-0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the United States Government.