Three Dimensional Aviation-Specific Hydrometeor Classification for Polarimetric WSR-88D Network

Regarding polarimetric radar techniques for aviation weather applications, dual-polarization capability is able to provide a detailed discrimination between different types of hydrometeors, which can be useful for severe weather warnings, airport de-icing operations as well as in-flight icing hazard warnings. The multi-radar-multi-sensor (MRMS) system can be used to develop and test new Federal Aviation Administration (FAA) NextGen products in addition to advancing techniques in quality control, icing detection, and turbulence. The goal of this work is to create a real-time national three-dimensional (3D) hydrometeor classification product that is specific for the aviation in-flight safety using the MRMS platform.

Based on the ten pre-defined hydrometeor or non-hydrometeor classes in the National Weather Service operational hydrometeor classification algorithm (HCA), the aviation-specific hydrometeor classification (ASHC) grid is developed using the inputs of single radar HCA products and hourly 3D temperature analysis fields from the NOAA Rapid Refresh (RAP) model. It includes six aviation specific categories: 1) no precipitation, 2) liquid precipitation, 3) precipitation with icing potential, 4) precipitation with icing hazards, 5) frozen precipitation, and 6) hail. With an updating frequency of 5-minute, the product grid has a horizontal resolution of ~1km and has 31 vertical levels that are corresponding to the flight levels. The ASHC algorithm has been tested with winter and summer precipitation cases involving multiple radars. The products show consistence between the adjacent radars and they are more directly relevant to the aviation applications. The ASHC will be implemented in the real time research bed of MRMS for further testing.