Manuscript files for "Idealized Simulations of Supercell Thunderstorms Near Stationary Boundaries" by Jasen Greco and Dr. Casey Davenport.

All of the BSS, input sounding, and namelist files used for the manuscript submission of "Idealized Simulations of Supercell Thunderstorms Near Stationary Boundaries" by Jasen Greco and Dr. Casey Davenport. Abstract of study: Synoptic-scale frontal boundaries are understood to be a source of intensification and severe weather production for supercell thunderstorms, owing to associated convergence and baroclinically-generated horizontal vorticity that can be tilted into the updraft. However, boundaries are also associated with strong spatial gradients in environmental quantities; separately, these variations are also known to influence storm intensity, longevity, and severe weather production. It is unclear whether the boundary circulation and associated vorticity or the rapid changes in the near-storm environment more significantly influence the known enhancements for supercells near boundaries. Thus, the research presented herein explores the contribution of a rapidly changing background environment consistent with a supercell crossing a frontal boundary (without the associated convergence or boundary circulation) via idealized simulations. The outcome from these simulations is designed to aid forecasters by providing a frame of reference for how supercell thunderstorms behave in frontal-boundary environments.The simulations used base-state environments rooted in an observed supercell-stationary boundary event on 29 May 2011. Representative environments were generated from model analyses on the warm-side, cold-side, and on the boundary itself. Idealized model experiments in CM1 tested each of these environments either fixed over time (control simulations), or varying over time via base-state substitution (BSS). Different types of boundary interactions were replicated through changes to the length of the transition between warm, cold, and boundary environments, as well as testing storm initiation on either side of the boundary (i.e., warm-to-cold versus cold-to-warm). While the control simulations indicated that the fixed boundary environment produced the strongest and longest lived supercell, all BSS experiments led to supercell dissipation. Overall, these simulations suggest that the boundary itself (i.e., associated convergence and vorticity) is an important contributor to the maintenance and severe weather production during supercell-boundary interactions. Implications for operations are described to emphasize this study’s applicability to operational forecasting.

本数据集包含Jasen Greco与Casey Davenport博士提交的论文《定常边界附近超级单体雷暴的理想数值模拟》（"Idealized Simulations of Supercell Thunderstorms Near Stationary Boundaries"）所使用的全部基态替换（Base-state Substitution，BSS）文件、探空输入文件与namelist文件。
研究摘要：天气尺度锋面边界被普遍认为是超级单体雷暴增强并引发强天气的关键诱因，这是由于其伴随的辐合运动与斜压过程生成的水平涡度，可被抬升进入上升气流。然而，锋面边界同时也会造成环境参量出现显著的空间梯度；此类环境变化本身也已被证实会对风暴强度、生命周期与强天气产生产生影响。目前尚不明确，究竟是边界环流与伴随的涡度，还是风暴近源环境的快速变化，对边界附近超级单体的已知增强效应起到更主导的作用。因此，本研究通过理想数值模拟，探究与超级单体穿越锋面边界场景一致的快速变化背景环境的贡献（模拟中未设置伴随的辐合与边界环流）。本系列模拟的结果旨在为气象预报员提供参考框架，以理解超级单体雷暴在锋面边界环境中的行为特征。
本模拟的基态环境源自2011年5月29日一次观测到的超级单体-定常边界事件。研究从暖区、冷区及锋面边界本身的模式分析资料中生成典型环境场。利用CM1模式开展理想数值试验，分别测试三类环境场：一类是随时间固定的环境场（对照模拟），另一类是通过基态替换（BSS）实现随时间动态变化的环境场。通过调整暖区、冷区与边界环境间的过渡时长，以及在锋面边界两侧（即暖区向冷区一侧与冷区向暖区一侧）启动风暴，来复现不同类型的边界相互作用过程。
对照模拟结果显示，固定边界环境下产生的超级单体强度最强、生命周期最长；而所有基态替换（BSS）试验均导致超级单体消散。总体而言，本系列模拟表明，锋面边界本身（即伴随的辐合与涡度）是超级单体与边界相互作用过程中，维持风暴强度与产生强天气的重要贡献因素。本文还阐述了该研究对业务预报的启示，以强调本研究在业务预报中的实际应用价值。