Investigating Hail Core Signatures Using C-BAND Polarimetric Radar

Hail detection using information from S-band dual-polarization radar has been studied for many years. The characterization of the Zdr hole has been an important signature for the detection of hail on the surface. The central region of Argentina in South America shows a large numbers of severe hail events during spring and summer. This area is covered by a growing network of C-Band dual-polarization radar. The use of this information in the evaluation of hail signatures presents an important challenge in the region.

The present study analyze the 3-D structure of polarimetric variables during a hailstorm event developed on early afternoon of January 15th 2011 using the C-Band polarimetric radar located at the city of Anguil (36.54 deg S, 63.99 deg W). This storm is an intense supercell developed under an environment associated with strong conditional instability and deep vertical directional and speed shear.

Over the life cycle of the system, reflectivity (Zh), differential reflectivity (Zdr), differential phase shift (φDP), specific differential phase shift (KDP) and correlation coefficient (ρHV) are examined in the present case. Strong evidence of presence of hail associated with the presence of high values ​​of Zh,, accompanied with high values ​​of ZDR shows the strong Mie resonance in the high reflectivity core of the system below the melting layer. Low, and some negative values of KDP associated to the presence of large particles of hail that produce a sharp drop of ρHV is in agreement with previous studies of C-Band dual-polarization data. Crop damage localization data from an insurance companies are used to identify areas with hail damage on surface.