This study documents the response of a mature mesoscale convective system's rear-inflow jet to environmental changes in the near-surface temperature profile (i.e., thermodynamic stability) and lower-tropospheric vertical wind shear (i.e., environmental forcing for ascent). The associated manuscript (Crossett and Evans 2020) is currently under review for publication in the Journal of the Atmospheric Sciences. This repository contains Cloud Model version 1 (CM1; Bryan and Fritsch 2002, Monthly Weather Review) code, configuration namelist, and input sounding used to conduct all numerical simulations in this study. It also contains MATLAB and shell scripts used in the base-state sensitivity simulations, used to diagnose the rear-inflow jet's response to the environmental modifications described above, reported in the same manuscript. All files are included in the .tar.gz archive accompanying this record. The CM1 code is distributed according to the terms of the model's copyright: CM1 Numerical Model, Release 19.10 (cm1r19.10) 4 March 2020 ©2020 - University Corporation for Atmospheric Research Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.