This passage from the David Means’ story “Tree Line, Kansas, 1934” has a fun explanation of the difference between a hunch and a gut feeling.
A gut feeling finally becomes a hunch when it is transmuted into the form of clear, precise, verbal statements uttered aloud to a receptive listener—internal or external—who responds in kind. A hunch twists inside the sinews and bones, integrating itself into the physicality of the moment, whereas a gut feeling can only struggle to become a hunch, and, once it does, is recognized in retrospect as a gut feeling.
(via David Means: “Tree Line, Kansas, 1934” : The New Yorker)