Development of a Weather Forecasting Code:

A case study of a weather-forecasting code aimed to investigate the code development challenges, understand the development tools used, and document the findings for other developers. C omputational science is increasingly providing insight into scientific phenom-ena that have previously been studied only experimentally, observationally, or theoretically. Codes, the software projects written for computational science, generally have three main differences from traditional software projects, such as those from the commercial software domain. First, because these projects often per-form new scientific investigations, the requirements can’t be known in advance and must evolve over time. Second, the main driving force for these projects is producing correct, important scientific advances rather than ensuring software quality through formalized software engi-neering processes. Finally, these projects ’ developers tend to be domain scientists rather than software engineers, so they’re less likely to use any heavy software development processes.1–3 To better understand the impact these character-istics have on software development practices in the computational-science domain and to document lessons learned for similar projects ’ benefit, we per-formed a series of case studies of computational-science code development projects sponsored by th