<p>Future changes in extratropical cyclones (ETCs), their moisture transport, and their connection to atmospheric rivers (ARs) remain uncertain. Here, using downscaled simulations from the Community Earth System Model version 2 under the high-emissions scenario SSP5-8.5, we show that moisture uptake associated with intense North Atlantic ETCs will increase by ~14.5%, or ~3.29% per Kelvin of global warming by the end of this century. Subregional analysis revealed greater increases during the most intense cyclone stages, with changes of 52.1% (11.8% K⁻¹) in the eastern North Atlantic, 33.4% (7.6% K⁻¹) in the western North Atlantic, and 29.1% (6.6% K⁻¹) in the northern North Atlantic. Rather than a consistent increase within existing climatological source regions, the moisture origin exhibits a geographic shift, likely linked with changes in storm-track pathways and ocean circulation under warming. Using a novel method to couple ETC moisture sources with ARs, we demonstrate that while this coupling continues to be a defining characteristic at the basin scale, the strength of their association is projected to weaken. Historical differences between low- and fully associated ETCs, particularly in terms of moisture sources and proximity to the AR axis, diminish and lose significance in a warming climate.</p>