Limited Area Model

Known in meteorological jargon by the acronym LAM, this is a numerical prediction model whose grid covers only a portion of the Earth's surface, nested within a general circulation model (GCM). To solve the mathematical equations at the points located at the boundaries of the integration area, these models need to have the information provided by the global model. The variables forecast by the GCM to which the LAM is coupled determine its boundary conditions. Although it has a higher horizontal resolution than a GCM, it depends on the GCM's degree of accuracy, which represents an important limitation. These models are commonly used to make short-range forecasts, less than 48 hours ahead.