We present an innovative approach to quantify basin-wide snowpack using calculations of spatial exceedance probability. Our method quantifies how the extraordinarily low snowpacks of 2014 and 2015 in the Pacific Northwest of the United States compare to snowpacks in warmer conditions and the probability that similar snowpacks will occur. We present these extraordinarily low snowpacks as snow analogs to develop anticipatory capacity for natural resource management under warmer conditions.