Bring a large pot of lightly salted water to a boil. Add pasta and cook till firm-tender.
Meanwhile, stir Alfredo sauce in a medium saucepan over medium-low heat until simmering. Add salmon and, stirring gently with a rubber spatula, simmer 1-2 minutes or until fish is opaque. Cover; remove from heat.
Remove 1/3 cooking water from pot. Drain pasta, return to pot. Add sauce, reserved cooking water, dill, and lemon zest. Gently turn with a rubber spatula to mix and coat.