Recent advances in receiving and distributing high resolution NEXRAD and commercial weather radar data at 1-km resolution nationally have enabled fine-scale estimates of precipitation to be produced for commercial customers. However the ability to classify the form of the precipitation at the earth’s surface has not been available at the same resolution since these classifications rely upon detailed knowledge of the temperature structure of the atmosphere. This knowledge is simply not available at the time and spatial resolution necessary.

There are many situations in which the form of the precipitation is critical. In particular for one of the most devastating of weather phenomena, freezing rain, the accumulated amounts, location, and extent of freezing rain are vital information for decisions in the transportation and power industries.

This paper describes a system for combining high-resolution radar data with information from the MM5 meteorological model. A parameterization of sub-gridscale hydrometeorological processes is applied to the MM5 data to yield classification of precipitation form at a resolution comparable to the radar data.