A roof vent assembly and roof flashing for facilitating a seal between an inclined roof surface having a longitudinal contoured profile and a upstanding vent member extending through said roof surface are disclosed. The roof flashing includes a base plate having respective aprons extending from opposing sides of the base plate, wherein the aprons have a contoured profile conforming to the longitudinal contoured profile of the inclined roof surface and an aperture centrally disposed in the base plate. The aperture is configured to encompass a periphery of the upstanding vent member when the base plate is mounted on the inclined roof surface and the contoured profiles of the aprons are superimposed on the longitudinal contoured profile of the inclined roof surface.