Basara, JeffreyBrauer, Noah2019-07-222019-07-222019https://hdl.handle.net/11244/321041Hurricane Harvey produced widespread rainfall amounts over 1000 mm in portions of Southeast Texas, including Houston from 26-31 August 2017. The highly efficient and prolonged warm rain processes associated with Harvey played a key component in the catastrophic flooding that occurred throughout the region. Precipitation efficiency (PE) is widely referred to in the scientific literature when discussing excessive precipitation events that lead to catastrophic flash flooding, but has yet to be explored or quantified in tropical cyclones coincident with polarimetric radar observations. With the introduction of dual-polarization radar to the NEXRAD WSR-88D network, observed polarimetric radar variables such as ZH, ZDR, and KDP can be used to gain insight into the precipitation processes that contribute to enhanced PE. It is found that 6-hour mean values of ZH between 35-45 dBZ, ZDR between 1-1.5 dB, and KDP greater than 1.5 degrees/km were collocated with the regions of highest PE between 27-29 August. Additionally, supercell thunderstorms embedded in the outer bands of Harvey were identified via 3-6 km MRMS rotation tracks and were found to be collocated with swaths of enhanced positive ZH, ZDR, and KDP.. The R(KDP,ZDR) relationship demonstrated that 1-hour mean rainfall rates in these supercells were as high as 85 mm/hour and played a significant contribution to the excessive precipitation event that occurred over the region.HydrometeorologyRadar MeteorologyTropical CyclonesExcessive Precipitation