This paper analyzes the translation strategies used by the Spanish Translation Section of the World Meteorological Organization (WMO) to address lexical and institutional style inconsistencies within its institutional and scientific-technical translation work in WMO documentation. Adopting a qualitative approach, the research defines the professional translator’s decision-making process by examining the results of four case studies derived from a compiled WMO corpus. The findings rigorously validate the leading role of strategic or methodological competence, which guides other competences such as thematic, linguistic, and textual in the resolution of translation challenges by consistently prioritizing communicative functionality and intertextual coherence over adherence to linguistic norms. This prioritization is evident in the implementation of core strategies, including conceptual normalization, lexical differentiation, and pragmatic stylistic adaptation. The study concludes that the institutional translator functions as a normalization agent and active mediator. This crucial role is effectively sustained by the expert knowledge management enabled by the thematic, heuristic, instrumental and textual competences.