That question is at the heart of a cert petition before the Supreme Court. In United States v. Robinson the court may decide to consider:
Whether, or under what circumstances, in a state that permits residents to legally carry firearms while in public, an officer's belief that a person is armed allows the officers to infer for purposes of a Terry v. Ohio search that the person is “presently dangerous.”Below, the 4th Circuit determined that all that was required was for the officer "reasonably suspect that the person was armed." But, as the Petitioner points out, Terry seems to require more - either reasonable suspicion that the person committed or is about to commit a crime, or evidence that the person is armed and presents a present danger.
Because Kansas is such a state with expanded gun rights, we should be raising this issue and keeping an eye on this interesting petition.