The use of NWP data in polarimetric hydrometeor classification

As polarimetric radar technology matures, aviation interests will increasingly take advantage of this platform's ability to discriminate between hydrometeor types. Data were collected by KOUN, the NSSL prototype polarimetric WSR-88D, during a winter storm on 3-4 December 2002. The NSSL polarimetric Hydrometeor Classification Algorithm was run using temperature data from the Rapid Update Cycle (RUC) numerical model and surface weather observing stations to help dicriminate between areas of freezing, frozen, and liquid precipitation. This output is compared to a run of the hydrometeor classification algorithm using no environmental or model information. While polarimetric radar alone can distinguish between solid and liquid precipitation falling at moderate to heavy rates, the radar cannot distinguish between rain and freezing rain.