Met Office Unified Model

The Met Office Unified Model (UM) is the numerical modelling system developed and used at the Met Office. It is unique, because it has been designed to allow different configurations of the same model to be used to produce all our weather forecasts and climate predictions. The system has been in continual development since 1990, taking advantage of steadily increasing supercomputer power, improved understanding of atmospheric processes, and an increasing range of observational data sources.

The UM is highly versatile, capable of modelling a wide range of time and space scales including kilometre-scale mesoscale nowcasts, limited-area weather forecasts, global weather forecasts (including the stratosphere), seasonal foreasts, global and regional climate predictions as well as being run as part of an ensemble prediction system.

In addition, the UM can be coupled to other models which represent different aspects of the Earth's environment that influence the weather and climate, such as the ocean and ocean waves, sea-ice, land surface, atmospheric chemistry and carbon cycle. This allows the Met Office Unified Model to be used for Earth System Modelling applications.

The Met Office Unified Model is run in many different configurations at the Met Office:

• a high-resolution model over the UK, to help predict the weather a few hours ahead
• a model over the North Atlantic and Europe (NAE) to predict the weather one to two days ahead, run as part of a short-range limited area ensemble MOGREPS
• a global model to predict the weather several days ahead, run as part of a medium-range global ensemble
• a seasonal forecasting model (GloSea) coupled with an ocean model to predict the likely trends over the coming six months
• a decadal prediction system (DePreSys)
• a regional climate model (PRECIS)
• a global climate model to predict up to a century ahead (HadGEM)

Find out more about operational weather forecast model configurations

How you can use the Met Office Unified Model

The UM is available for external use under licence. A number of research organisations and national meteorological services use the UM in collaboration with the Met Office to undertake basic atmospheric process research, produce forecasts, develop the Unified Model code and build and evaluate Earth System Models.

For further information on the opportunities available for collaboration, please contact the Unified Model Collaboration Manager via our Customer Centre.

For further details and to apply for a licence, please contact the IPR manager via our Customer Centre.