This study investigates temperature impacts to snowpack and runoff-driven flood risk over the Sierra Nevada during the extremely wet year of 2016-2017. Significant findings have been revealed related to recent public-aware precipitation extremes. With a reasonably accurate representation of the historical precipitation and snowpack over the Sierra Nevada, results from the offline simulations with perturbed near-surface temperature reveal significant impacts of warming on SWE loss and flood risk. One of the main findings involves the existing impacts of the Sierra Nevada hydrology by human-induced warming and continuing impact under future warming. In a word, current wet year put in the future will be almost like a nowadays' dry year. Along with the snowpack loss, a notable second effect of warming is intensified flood risk due to increased runoff over heavy-rainy days. As the drought condition predicts to be more severe and precipitation to be more extreme,  the loss of snowpack and intensified flood risk inform policy-makers for better climate adaptation strategies for water resources supply and flood control.