Identifying factors associated with the progression from recreational to pathological drinking in youth holds high clinical and theoretical importance. The present study tested cross-sectional associations of alcohol use disorder (AUD) severity with putative mechanisms of AUD progression among youth ages 15–24 years, namely acute subjective effects of alcohol and craving. Male (n = 44) and female (n = 42) youth completed ecological momentary assessments when not drinking, just before drinking, and while drinking in the natural environment via handheld wireless devices. Youth were recruited from the community and were frequent and heavy drinkers, the majority (93%) with at least 1 AUD symptom (M = 3.4, SD = 2.4). Findings from youths’ daily lives suggested that how youth feel while they drink depends, in part, on their severity of AUD pathology. In support of hypotheses, youths with more progressed drinking pathology (i.e., those with more symptoms of AUD) reported greater reductions in craving and tension while drinking, relative to nondrinking times. In partial support of hypotheses, males with greater AUD symptomatology reported marginally attenuated increases in stimulatory states while drinking; however, contrary to hypotheses, females with greater AUD symptomatology reported enhanced increases in stimulation while drinking. This research leveraged ecological momentary assessment methods to study subjective responses to alcohol and craving in youths’ daily lives and to cross-sectionally test putative associations with AUD etiology. This work adds to literature supporting subjective responses to alcohol in the pathogenesis of alcoholism, specifically by highlighting their importance during the period in life when alcohol problems typically first emerge.