Recent work in intonational phonology has shown that L and H points are carefully controlled by the speaker, i.e., they are scaled and synchronized with the segmental material in extremely consistent ways (Arvaniti, 2003; Arvaniti, Ladd, & Mennen, 1988, 2000; Ladd, 2003; Liberman and Pierrehumbert, 1984; Prieto, van Santen, & Hirschberg, 1995; Xu, 1999, 2000, among others). Similarly, it has been shown that pitch pressure environments (namely, proximity to a boundary tone or to an upcoming pitch accent) can drastically affect surface H alignment patterns (Silverman & Pierrehumbert, 1990; Prieto, Shih, & Nibert, 1995). What is less well known are the effects of time and pitch pressure environments on surface scaling and L alignment patterns and whether stability effects are found in these domains. This paper discusses the effects of tonal clash (or strict adjacency between two accents) on the phonetic realization of rising prenuclear accents in Catalan. The analysis of the data shows that the adjacency of two rising accents triggers a drastic temporal reorganization of the f0 gestures involved, resulting in anticipation of the first gesture and delay of the first L of the second. The data thus reveals that f0 gestures are roughly timed to accented syllables, keeping a more or less floating relationship with the segmental string. Importantly, no significant differences are found on H scaling in clash vs. nonclash environments, revealing that these points work as real production targets. Moreover, in tonal clash contexts the time of the second tonal rise significantly shortens and the velocity of the rising gesture significantly increases in order to reach a given scaling target. Therefore, the results of the present study reveal that, in pitch pressure environments, a clear contrast is found between the stability effects of the H scaling domain and the adapting behavior of the time and velocity domains. © 2005 Elsevier Ltd. All rights reserved.