This section will explain on how to download TerraClimate's precipitation (ppt) and potential evapotranspiration (pet) monthly data in netCDF format and prepare it as input for Standardized Precipitation-Evapotranspiration Index (SPEI) calculation.
This step-by-step guide was tested using Mac mini Server - Late 2012, 2.3 GHz Quad-Core Intel Core i7, 16 GB 1600 MHz DDR3, running on macOS Catalina 10.15.7 and Windows 10 with Windows Subsystem for Linux enabled running on Thinkpad T480 2019, i7-8650U 1.9GHz, 64 GB 2400 MHz DDR4.