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To better constrain model simulations, more observations of convective detrainment heights are needed. For the first time, ground‐based S band radar observations are utilized to create a comprehensive view of irreversible convective transport over a 7‐year period for the months of May and July across the United States. The radar observations are coupled with a volumetric radar echo classification scheme and a methodology that uses the convective anvil as proxy for convective detrainment to determine the level of maximum detrainment (LMD) for deep moist convection. The LMD height retrievals are subset by month (i.e., May and July), by morphology (i.e., mesoscale convective system, MCS, and quasi‐isolated strong convection, QISC), and region (i.e., northcentral, southcentral, northeast, and southeast). Overall, 135,890 deep convective storms were successfully sampled and had a mean LMD height of 8.6 km or tropopause‐relative mean LMD height of4.3 km; however, LMD heights were found to extend up to 2 km above the tropopause. May storms had higher mean tropopause‐relative LMD heights, but July storms contained the highest overall LMD heights that more commonly extended above the tropopause. QISC had higher mean tropopause‐relative LMD heights and more commonly had LMD heights above the tropopause while only a few MCSs had LMD heights above the tropopause. The regional analysis showed that northern regions have higher mean LMD heights due to large amounts of diurnally driven convection being sampled in the southern regions. By using the anvil top, the highest possible convective detrainment heights extended up to 6 km above the tropopause.

We gridded 11 years of cloud‐to‐ground (CG) flashes detected by the U.S. National Lightning Detection Network during the warm season in 15 km × 15 km × 15 min grid cells to identify storms with substantial CG flash rates clearly dominated by flashes lowering one polarity of charge to the ground or the other (+CG flashes vs. −CG flashes). Previous studies in the central United States had found that the gross charge distribution of storms dominated by +CG flashes included a large upper negative charge over a large middle level positive charge, a reversal of the usual polarities. In each of seven regions spanning the contiguous United States (CONUS), we compared 17 environmental parameters of storms dominated by +CG flashes with those of storms dominated by –CG flashes. These parameters were chosen based on their expected roles in modulating supercooled liquid water content (SLWC) in the updraft because laboratory experiments have shown that SLWC affects the polarity of charge exchanged during rebounding collisions between riming graupel and small ice particles in the mixed phase region. This, in turn, would affect the vertical polarity of a storm's charge distribution and the dominant polarity of CG flashes. Our results suggest that the combination of parameters conducive to dominant +CG flash activity and, by inference, to anomalous storm charge structure varies widely from region to region, the lack of a favorable value of any particular parameter in a given region being offset by favorable values of one or more other parameters.

The convectively driven transport of soluble trace gases from the lower to the upper troposphere can occur on timescales of less than an hour, and recent studies suggest that microphysical scavenging is the dominant removal process of tropospheric ozone precursors. We examine the processes responsible for vertical transport, entrainment, and scavenging of soluble ozone precursors (formaldehyde and peroxides) for midlatitude convective storms sampled on 2 September 2013 during the Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC⁴RS) study. Cloud‐resolving simulations using the Weather Research and Forecasting with Chemistry model combined with aircraft measurements were performed to understand the effect of entrainment, scavenging efficiency (SE), and ice physics processes on these trace gases. Analysis of the observations revealed that the SEs of formaldehyde (43–53%) and hydrogen peroxide (~80–90%) were consistent between SEAC⁴RS storms and the severe convection observed during the Deep Convective Clouds and Chemistry Experiment (DC3) campaign. However, methyl hydrogen peroxide SE was generally smaller in the SEAC⁴RS storms (4%–27%) compared to DC3 convection. Predicted ice retention factors exhibit different values for some species compared to DC3, and we attribute these differences to variations in net precipitation production. The analyses show that much larger production of precipitation between condensation and freezing levels for DC3 severe convection compared to smaller SEAC⁴RS storms is largely responsible for the lower amount of soluble gases transported to colder temperatures, reducing the amount of soluble gases which eventually interact with cloud ice particles.