WAFC London Performance Indicators

These plots show the performance of WAFC London forecasts produced by the Met Office in the United Kingdom.

Wind and temperature

All the wind and temperature plots are for forecasts for 24 hours ahead at 00 and 12 UTC for various pressure levels. The levels provided with their approximate equivalent Flight Levels are 850 hPa (FL050), 700 hPa (FL100), 600 hPa (FL140), 500 hPa (FL180), 400 hPa (FL240), 300 hPa (FL300), 250 hPa (FL340), 200 hPa (FL390), 150hPa (FL450), 100 hPa (FL530).

The wind and temperature plots cover seven different areas. Area 2 is a Met Office-defined area, covering the north Atlantic and parts of western Europe and North America. We have a long, time series of data for this area which shows a steadily improving performance over the years.

WAFC Performance - Area 2 Area 2 map

Most of the remaining areas are defined by the World Meteorological Organization Commission for Basic Systems (CBS) to allow comparisons to be made between different modelling centres.

In both cases, the forecasts are compared against the model's analysis for the same time. For wind, the computed errors are root-mean-square vector errors - this takes into account errors in the wind direction as well as the wind speed. For temperature, the errors are root-mean-square errors. The units are metres per second for wind and Kelvin (or degrees Celsius) for temperature.


The timeliness plots show the time of availability of the WAFS GRIB and BUFR data on Met Office systems. To simplify the collection and presentation of data, the availability of only one of the many bulletins that are disseminated each day is assessed. The plots show the time within which the selected bulletin was ready for transmission on 95% of occasions during each month. On the other 5% of occasions the bulletins were ready later. In practice, users will receive their data later than the times indicated here, as the bulletins have to be switched to users via SADIS or other means.