Dual Polarization Hail Detection
- Base Reflectivity - Reflectivity will indicate an intense thunderstorm with strong returns typically above 55 dbZ in the area of the hail core.
- Specific Differential Phase - KDP samples the volume for liquid content, so the returns can vary depending on the wetness of the hail and if rain is mixed in with the core. Hail tends to tumble as it falls and will appear to be spherical to the radar. This will usually give a near 0 degress of differential phase shifting. Typical returns for melting hail will be greater than 1.5 deg/km.
- Differential Reflectivity - ZDR values will return very low, near zero. This is a result of the hail tumbling and appearing circular to the radar.
- Correlation Coefficient - CC values will be reduced in the hail core region. The hail might be mixed with rain or have different sizes. Typical values for hail larger than golf balls are less than 0.85.
Example Radar Image