TY - JOUR
T1 - Cold pool characteristics of tornadic quasi-linear convective systems and other convective modes observed during VORTEX-SE
AU - McDonald, Jessica M.
AU - Weiss, Christopher C.
N1 - Funding Information:
Acknowledgments. This work was supported by National Oceanic and Atmospheric Administration Grants NA16OAR4590227 and NA17OAR4590206. We thank Dr. Vanna Chmielewski, Dr. Aaron Hill, Dr. Eric Bruning, and Abby Hutson for their work in deploying and maintaining the StickNets during this project and providing assistance with developing the coding infrastructure to analyze the StickNet data. We are also grateful for the helpful comments from Dr. Matt Parker and two anonymous reviewers that improved the quality of this work. The interpolated fields in Figs. 8 and 14 were produced using the MetPy Python package (May et al. 2020), the WSR-88D data in Figs. 3, 4, 9, 11, 10 and 15 were plotted using the Py-ART Python package (Helmus and Collis, 2016), and the base maps in Figs. 1, 4, 5, 8, 9, 10, 11, 14 and 15 were provided by Cartopy (Met Office 2015). The 13-km RAP data were accessed and processed using the Siphon Python package (May et al. 2017).
Publisher Copyright:
© 2021 American Meteorological Society.
PY - 2021/3
Y1 - 2021/3
N2 - Many numerical studies have focused on the importance of baroclinically generated vorticity at the edge of cold pools in supercellular tornadogenesis, and observational work has consistently found that strongly tornadic supercells have less dense, more buoyant cold pools than weakly or nontornadic supercells. However, there is a lack of observational studies that consider potential relationships between cold pool characteristics (e.g., density) and tornado productionwithin linear systems, such as mesoscale convective system (MCS) or quasi-linear convective system (QLCS) events. This study presents two tornadic QLCS events that were observed during the Verification of the Origins of Rotation in Tornadoes Experiment-Southeast (VORTEX-SE) field project in 2016 and 2017. Supercell and hybrid modes were also observed and compared to the observations from the linear systems. No obvious differences in the thermodynamic deficits of the tornadic and nontornadic samples were found, likely due to the weakness of the produced tornadoes (≤EF1) and the small tornadic sample size (five cold pools). Comparison across storm mode did find some differences, with QLCS cold pools producing larger virtual potential temperature and psuedoequivalent potential temperature deficits than those observed in supercells. More importantly, our findings suggest that, in a QLCS, the magnitude of density gradients along the leading edge of the cold pool may be related to tornadogenesis by virtue of the implied baroclinic vorticity generation.
AB - Many numerical studies have focused on the importance of baroclinically generated vorticity at the edge of cold pools in supercellular tornadogenesis, and observational work has consistently found that strongly tornadic supercells have less dense, more buoyant cold pools than weakly or nontornadic supercells. However, there is a lack of observational studies that consider potential relationships between cold pool characteristics (e.g., density) and tornado productionwithin linear systems, such as mesoscale convective system (MCS) or quasi-linear convective system (QLCS) events. This study presents two tornadic QLCS events that were observed during the Verification of the Origins of Rotation in Tornadoes Experiment-Southeast (VORTEX-SE) field project in 2016 and 2017. Supercell and hybrid modes were also observed and compared to the observations from the linear systems. No obvious differences in the thermodynamic deficits of the tornadic and nontornadic samples were found, likely due to the weakness of the produced tornadoes (≤EF1) and the small tornadic sample size (five cold pools). Comparison across storm mode did find some differences, with QLCS cold pools producing larger virtual potential temperature and psuedoequivalent potential temperature deficits than those observed in supercells. More importantly, our findings suggest that, in a QLCS, the magnitude of density gradients along the leading edge of the cold pool may be related to tornadogenesis by virtue of the implied baroclinic vorticity generation.
KW - Baroclinic flows
KW - Cold pools
KW - Convective storms/systems
KW - Severe storms
KW - Squall lines
KW - Surface observations
KW - Tornadogenesis
KW - Updrafts/downdrafts
UR - http://www.scopus.com/inward/record.url?scp=85103590126&partnerID=8YFLogxK
U2 - 10.1175/MWR-D-20-0226.1
DO - 10.1175/MWR-D-20-0226.1
M3 - Article
AN - SCOPUS:85103590126
VL - 149
SP - 821
EP - 840
JO - Monthly Weather Review
JF - Monthly Weather Review
SN - 0027-0644
IS - 3
ER -