Microphysical and Transportive Contributions to Normal and Anomalous Polarity Subregions in the 29–30 May 2012 Kingfisher Storm

Abstract

A developing supercell storm on 29–30 May 2012 in north‐central Oklahoma was observed with the Oklahoma Lightning Mapping Array (OKLMA) and three mobile radars. The storm's vertical charge structure inferred from the OKLMA was anomalous overall but varied considerably even within 10 km of the bounded weak echo region (BWER) and the bounded weak lightning region (BWLR) or lightning hole. Near the BWER, three distinct charge structures were observed—an inverted dipole, an inverted tripole, and a bottom‐heavy normal tripole. One column within each structure was analyzed relative to the Doppler‐derived wind field and environmental properties derived by a diabatic Lagrangian analysis (DLA). Within each column, back trajectories of graupel and hail particles additionally illustrate the history of the diagnosed in‐cloud microphysical properties, which are expected to influence noninductive electrification and may have contributed to the observed charge profiles. This study objectively demonstrates the complicated scenarios presented by the three‐dimensional motions around and through the updraft and provides likely constraints on how each of the three distinct vertical charge distributions could have been produced within this focused region of the storm.

Examining Conditions Supporting the Development of Anomalous Charge Structures in Supercell Thunderstorms in the Southeastern United States

“…Therefore, the most likely region of positive charging of riming hydrometeors did not strictly coincide with storm maximum updraft speeds, as similarly observed by Chmielewski et al. (2020), and it is not suggested that the ACSs arose because of these elevated maximum updrafts. Rather, these updrafts may have been influenced by conditions that either more directly contributed to or were related to ACS development.…”

“…At these temperatures, collisional NIC involving riming hydrometeors would have been inactive as a result of homogeneous freezing (although studies have shown that some amount of charging may occur in the absence of LWC, e.g., Dye & Bansemer, 2019;Emersic & Saunders, 2020;Mitzeva et al, 2006). Therefore, the most likely region of positive charging of riming hydrometeors did not strictly coincide with storm maximum updraft speeds, as similarly observed by Chmielewski et al (2020), and it is not suggested that the ACSs arose because of these elevated maximum updrafts. Rather, these updrafts may have been influenced by conditions that either more directly contributed to or were related to ACS development.…”

“…Within the mixed‐phase region, similar arguments apply as were discussed with respect to low‐level updrafts. Large, fast updrafts are more resistant to entrainment of dry air and may be less favorable for particle recirculation which can increase competition for LWC and reduce riming efficiency (Chmielewski et al., 2020; Fuchs & Rutledge, 2018; MacGorman et al., 2005, 2011; E. R. Williams et al., 2005).…”

“…This complexity could have been attributed to three‐dimensional variability in kinematics as well as cloud microphysical properties. That is, conditions within the updraft may have been variably favorable for both anomalous and normal charging, with predominantly anomalous charging occurring in the net perspective (e.g., Chmielewski et al., 2020). The structural similarities between the anomalous April 22, 2017 storm and the normal storms support this possibility, as do indications of some environmental overlap.…”

Hurricane Florence (2018): Long duration single‐ and dual‐Doppler observations and wind retrievals during landfall

“…Past wind retrievals using the SMART radars have elucidated the structure and evolution of supercell thunderstorms (Bela et al, 2018; Betten et al, 2018; Calhoun et al, 2013; Davenport et al, 2019; DiGangi et al, 2016; Fried et al, 2016; Huntrieser et al, 2016; Li et al, 2017; Skinner et al, 2011) and mesoscale convective systems (Barth et al, 2015; Geerts et al, 2017; Lund et al, 2009; Miller et al, 2020; Palucki et al, 2011). The relationship between radar observed kinematics and cloud electrification for both natural lightning (Biggerstaff et al, 2017; Bruning et al, 2010; Chmielewski et al, 2020; Kuhlman et al, 2009; MacGorman et al, 2008; Payne et al, 2010) and triggered lightning (Hare et al, 2016; Hill et al, 2013; MacGorman et al, 2015; Pilkey et al, 2013) has also been studied with SMART radar observations. Additionally, the boundary layer structure of landfalling TCs has been documented using SMART radars (Alford et al, 2020; Hirth et al, 2012; Knupp et al, 2006; Lorsolo et al, 2008), as has the existence of mesovortices along the inner edge of hurricane eyewalls (Alford et al, 2019b; Fernandez‐Caban et al, 2019).…”