WAFC London Performance Indicators

Verification statistics for the World Area Forecast Centre (WAFC) London data sets are produced by the Met Office for a range of different regions. Most regions correspond to those defined by the World Meteorological Organization (WMO) Commission for Basic Systems (CBS) to allow comparisons to be made between different modelling centres. Area 2 is a Met Office defined area covering the north Atlantic and parts of western Europe and North America. An additional area covering the Middle East is also provided.

Wind and temperature plots

Wind and temperature plots for 24 hours ahead (T+24) are created using data from all four model runs that are issued each day for a range of pressure levels.

The forecasts are compared against the model’s analysis (i.e. T+0) for the same time to create plots of the Root Mean Square (RMS) error. For wind, the computed error takes into account errors in the wind direction as well as the wind speed, with the error provided in units of m/s. For temperature, the RMS errors are in Kelvin (or degrees Celsius).

The time series used in most plots commences in 2000 or 2001, and shows a steady improvement in performance over the years.

Download wind and temperature plots (zip file)

Turbulence and Cumulonimbus plots

WAFS plots for Clear Air Turbulence (CAT) and cumulonimbus (CB) show the performance of the blended WAFC London and WAFC Washington data sets. Receiver Operating Characteristic (ROC) curves and contingency tables are provided, which compare the forecast hit rate and false alarm rate, “miss rate” and “false alarm rate”. Data is available for three forecast timesteps: T+12, T+24 and T+36, and for a 1 year period.

CAT is verified against automated aircraft observations of turbulence. A Derived Equivalent Vertical Gust (DEVG) exceeding 4.5 m/s represents moderate to severe turbulence. Verification of both the mean CAT (the average value produced by blending the WAFC London and WAFC Washington data) and max CAT (the highest of value produced by either of the two WAFC data sets) is provided.

Cumulonimbus Extent is verified against observed lightning and satellite imagery.

Download CAT/CB plots and contingency tables (zip file)

Timeliness plots

The timeliness plots show the time at which the WAFS GRIB and BUFR data is fully available on the SADIS system. Statistics are generated using all four model runs and therefore the plots show time elapsed instead of an actual issue time. For example 06 UTC model GRIB hazard data is typically available at approximately 09:35 UTC, whilst the hazard GRIB data is available at approximately 10:10 UTC.

BUFR

WAFS SIGWX timeliness

GRIB

WAFS GRIB timeliness

Get in touch

Call us

We are available 24/7.

0370 900 0100

Email us

Fill out this short form and we'll get back to you.

Contact Us form

Follow us

Linkedin Twitter

Get in touch

Call us

We are available 24/7.

0370 900 0100

Email us

Fill out this short form and we'll get back to you.

Contact Us form

Follow us

Linkedin Twitter