Preliminary Observations of Weak Three-Body Scatter Spikes Associated With Low-End Severe Hail

he three-body scatter spike (TBSS), an artifact caused by radar microwave scattering associated with large hydrometeors, traditionally has been utilized in the National Weather Service as operational indicator of destructive hail. Severe weather warning strategies based on TBSS were derived using a lower-bound reflectivity threshold 5 dBZ. With recent WSR-88D workstation software and product upgrades, display very low value data to -30 dBZ allowed meteorologists observe more subtle, but meaningful, atmospheric targets artifacts. Since these radar-based interrogations thunderstorms over west Texas South Dakota (among other places) have revealed weak signatures characterized faint returns -14 A sufficient dataset cases does not exist currently support robust statistical analysis. Preliminary observations, however, indicate that may occur prior during low-end severe hail measuring between 1.9 cm 2.5 diameter, especially when recognized emanate from pulse-type convective storms sampled at close range Great Plains. These observations suggest extension current conceptual use conventional model, which associates traditional signature likelihood “very hail,” should be investigated.