Moving legacy software systems to cloud platforms is an ever popular option. But, such an endeavour may not be hazard-free and demands a proper understanding of requirements and risks involved prior to taking any actions. The time is indeed ripe to undertake a realistic view of what migrating systems to the cloud may offer, an understanding of exceptional situations causing system quality goal failure, and insights on countermeasures. The cloud migration body of knowledge, although is useful, is dispersed over the current literature. It is hard for busy practitioners to digest, synthesize, and harness this body of knowledge into practice in a scenario of integrating legacy systems with cloud services. We address this issue by creating an innovative synergy between the approaches evidence-based software engineering and goal-oriented modelling. We develop an evidential repository of commonly occurred obstacles and platform agnostic resolution tactics related to making systems cloud-enabled. The repository is further utilized during the systematic goal-obstacle elaboration of given cloud migration scenarios. The applicability of the proposed framework is also demonstrated.