CSB Thunderstorm adds atmosphere to any map. On a schedule whose frequency scales with an intensity cvar, the sky flashes: a brief white ScreenFade plus a bright TE_DLIGHT above each player, followed a beat later by a thunder sound. Admins can call a strike on demand with amx_thunder. It is purely cosmetic and changes nothing about gameplay.
amx_thunder triggers a strike on demand.csb_thunderstorm.sma, copy it to addons/amxmodx/plugins/ and add it to plugins.ini.sound/ambience/thunder_clap.wav or edit the path in the source.