Wednesday, 30 August 2023: 2:45 PM
Great Lakes BC (Hyatt Regency Minneapolis)
We present an overview of Purdue’s activities in the 2023 season of the Propagation, Evolution and Rotation in Linear Storms (PERiLS) field program. Jointly funded by NSF and NOAA, PERiLS is the first large-scale field program designed specifically to study tornadoes from quasi-linear convective systems (QLCSs) and focuses on the southeast-U.S. as its domain of operations (through a number of predefined subdomains), owing to the juxtaposition of meteorological and societal factors that make this region particularly vulnerable to QLCS tornadoes.
Under this broad umbrella, the main scientific objective of our group is to uncover connections between QLCS microphysics, cold pool strength and gust front structure, and tornadogenesis potential. In particular the processes of evaporative cooling and hydrometeor size sorting are linked to cold pool/gust front dynamics and the low-level wind profile. Both are potentially linked to tornadogenesis processes and both may cause detectable changes in rain drop size distributions (DSDs) that can be directly observed by disdrometers and combined with complementary polarimetric and doppler radar observations aloft. Like in the 2022 season, the role of our Purdue-based team in 2023 was to deploy the Portable In Situ Precipitation Stations (PIPS) in a linear line-parallel array ahead of an approaching QLCS. The PIPS are six instrumented packages designed and built at NSSL and jointly owned and operated by Purdue, OU, and NSSL, each of which contains a Parsivel2 laser disdrometer along with standard meteorological instrumentation (temperature, relative humidity, pressure, and wind speed and direction). In this presentation, we will provide an overview of our operations in the four IOPs in which deployments were made (IOP2, 03/03/2023; IOP3, 03/24/2023; IOP4, 03/31/2023, and IOP5, 04/05/2023). These cases included a wide range of convective morphologies and severities, including both non-tornadic and tornadic QLCS and supercell modes. We will present preliminary analyses of the collected DSD data and comparison with polarimetric radar observations.
Under this broad umbrella, the main scientific objective of our group is to uncover connections between QLCS microphysics, cold pool strength and gust front structure, and tornadogenesis potential. In particular the processes of evaporative cooling and hydrometeor size sorting are linked to cold pool/gust front dynamics and the low-level wind profile. Both are potentially linked to tornadogenesis processes and both may cause detectable changes in rain drop size distributions (DSDs) that can be directly observed by disdrometers and combined with complementary polarimetric and doppler radar observations aloft. Like in the 2022 season, the role of our Purdue-based team in 2023 was to deploy the Portable In Situ Precipitation Stations (PIPS) in a linear line-parallel array ahead of an approaching QLCS. The PIPS are six instrumented packages designed and built at NSSL and jointly owned and operated by Purdue, OU, and NSSL, each of which contains a Parsivel2 laser disdrometer along with standard meteorological instrumentation (temperature, relative humidity, pressure, and wind speed and direction). In this presentation, we will provide an overview of our operations in the four IOPs in which deployments were made (IOP2, 03/03/2023; IOP3, 03/24/2023; IOP4, 03/31/2023, and IOP5, 04/05/2023). These cases included a wide range of convective morphologies and severities, including both non-tornadic and tornadic QLCS and supercell modes. We will present preliminary analyses of the collected DSD data and comparison with polarimetric radar observations.
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