Dr Adrian Semple

Areas of expertise

• Meteorology
• Numerical Weather Prediction
• Subjective Evaluation
• Model Error Tracking, Diagnosis and Sensitivity
• Conceptual Models of Cyclogenesis

Current activities

Adrian is a senior scientist working on the evaluation of the Unified Model when it is both operational and during its pre-operational development phases.  The Met Office is continually striving to improve its forecasting capability and regularly updates its forecast models with new science, new technology, and new mathematical techniques. This is a large and complex undertaking with many changes being introduced simultaneously, so rigorous tests are carried out to ensure that the skill of our forecasts continues to increase with each model upgrade. As part of this extensive testing, Adrian leads activities with operational forecasters to expertly interpret and appraise the new models to ensure that the meteorological science provided by them provides sound and improved guidance. Only when these tests have successfully been carried out will improvements be approved for the model to become operational.
Even operational models, however, can contain significant errors and investigation can sometimes identify their causes. Effective diagnosis of a forecast error requires an overall understanding of the technical aspects of the forecasting process along with a knowledge of the meteorological processes which have occurred and Adrian uses error tracking techniques which incorporate both these aspects. Understanding of the processes involved in error development and propagation can then help identify the dominant error source. Not all investigations lead to an identifiable error-source, however, due both to the complexity of the numerical weather prediction system and also the predictability issues which are inherent in any forecast. The application of diagnostic techniques developed in the course of post-event analysis has been found to be fruitful in the operational environment, aiding in the decision making process and improving the forecasting end-product. Adrian's work therefore provides a strong and important link between research and operational meteorology.

Career background

Prior to the Met Office, Adrian completed a Pure and Applied Physics Degree (first class) at Liverpool University, where he remained to complete a PhD in Nuclear Structure Physics and two years postdoctoral research. On joining the Met Office, Adrian worked for five years based at the University of Reading where he worked on a number of projects including the application of conceptual models of cyclogenesis in NWP. Here he developed a unification of these models which has since been used widely by operational forecasters and to teach the meteorology of cyclogenesis.