This study investigates how Svalbard's mountains modulate warm and moist air mass intrusions into the central Arctic, where such events are key drivers of warm extremes. Using atmospheric modeling, air parcel trajectories and observations from the MOSAiC expedition for a case in April 2020 and a climatological analysis for springtime in 2000–2022, we show that Svalbard can alter winds, temperatures, clouds and surface energy fluxes hundreds of kilometers downstream over sea ice.