Snowpacks act like high mountain reservoirs, but are vulnerable to climate change, while the vast majority of forest fires occur in the seasonal snow zone. Forest fires further exacerbate the influence of warming climate on snow-water storage through feedbacks between shifting post-fire forest-snow interactions. Charred forests shed black carbon and burned woody debris on snowpack which concentrates on the surface during snowmelt lowering snow surface albedo. These darkened snowpacks are primed to absorb proportionally more incoming solar radiation in the more open post-fire forests. Using empirical data from in-situ field measurements, long-term monitoring, and geochemical analysis, combined with multi-scale remote sensing, and physically-based snow modeling, we evaluate the spatial and temporal variability of forest fire effects on snow water storage and snowmelt across the West. The post-fire radiative forcing on snow decreases snow-water storage, advances the timing of snowmelt, and in high severity burned forests increases the rate of snowmelt across the western US for at least 10 years following fire.