Adolescent suicide is a critical problem in the United States. Identification and reporting of warning signs is a suicide prevention practice that is particularly important in schools, where adolescents spend the majority of their time. Though it is necessary to consider both risk factors and warning signs when evaluating an individual's suicide risk, warning signs are more indicative of a potentially impending suicide. However, there is a paucity of research on specific combinations of warning signs linked with increased suicide risk in the United States. Using data from the 2015-2016 Pennsylvania Youth Survey (PAYS), a latent profile analysis was conducted to identify patterns of warning signs. Three subgroups of adolescents were detected: (a) average moods and feelings; (b) negative moods and feelings; and (c) negative moods, feelings, thoughts, and behaviors. The patterns of warning signs among each profile are described, along with demographic details. The findings from the present investigation have important implications for gatekeeping practices, training, and screening in schools.