Abstract
Specific differential phase shift is one of three new base products that have become available to operational weather forecasters since the WSR-88D upgrades were completed in May 2013. Though most often used as a component in quantitative precipitation estimates, this research focused on determining if KDP is strong enough of a stand-alone product for meteorologists to use in weather warning decision-making. Radar and observation data from 17 convective storms and 8 locations during two land-falling tropical storms were studied. It was shown for convective storms that the single greatest KDP pixel value for each radar scan during the studied storms had a stronger relationship to observed rainfall rate than the highest base reflectivity pixel. It was also shown that current methods of precipitation estimate routinely overestimate rainfall amounts, while a new method that utilizes a Z-R relationship that uses only the base reflectivity values associated with the maximum KDP value provides a rainfall amount closer to in situ observations. These results lead to the conclusion that, using the methods utilized in this research, KDP is indeed strong enough to be used as a stand-alone product for forecasters.