One of the most extreme snowstorms ever documented, with among the highest 12- and 24-hour liquid-equivalent accumulations recorded globally, was captured by an ultra-high-elevation weather-station network on Mt. Everest on 4 October 2025. Beyond redefining expectations of extreme Himalayan snowfall magnitudes, the event revealed a relationship between precipitation intensity and phase: melting of precipitating hydrometeors cooled the atmosphere and suppressed rain at glacierised elevations, with the low-density, high-altitude atmosphere amplifying this feedback. As the climate warms, more extreme Himalayan precipitation is likely, but whether such events bring rain or snow—and therefore their impacts—will depend on fine-scale storm dynamics.