Recent results from this assessment are given in Table 1. Anomaly correlation coefficients for forecasts of 500 hPa heights over the northern hemisphere. Verification of a vector field, such as the wind, is more complicated. The error between two vectors is itself a vector. Although both have been improving, the vector wind error is rather more difficult to improve because it is affected by errors of direction as well as errors of speed.
Much more assessment is done for our own internal monitoring of the model performance.
This includes verification for the limited area model and for the UK mesoscale model, as well as for the two wave models in the Operational Suite. Verification against observations from individual stations is becoming increasingly useful. This kind of assessment can be used for forecasts of occurrence of rainfall where the assessment of continuous variables, as described above, has to be replaced by event-based assessment using contingency tables. The real value of verification is not just in monitoring the behaviour of the models. The results can highlight some of the strengths and weaknesses of the models, and this information, passed back to the modeller as part of an ongoing feedback process, can then help in the diagnosis of areas where the physics and dynamics can be used to bring further improvements in performance.