Architecture styles in the software world continue to evolve to present easier and more appealing ways of designing and building software systems to meet stakeholder needs. One of the popular trends at the moment is microservices. Microservice architecture is gaining the market of software development architecture due to its capability to scale. It separates independent small services of a system to perform one business capability at a time. However, determining the right size of business capability that could be called a microservice is still a challenge. Current practice of partitioning microservice relies on personal practice within industry which is prone to bias by practitioners. Based on the ambiguity of determining the optimum size of a microservice, in this paper, we propose a conceptual methodology to partition a microservice based on domain engineering technique. We demonstrate the usage of this methodology on the weather information dissemination domain as a confirmatory case study. We show how to split the weather information dissemination system sub-domain into different microservices that accomplish the weather information dissemination business capability.