On Sunday, 11 December 2005, a little after 6 a.m., there was a major explosion at the Buncefield Oil Depot in Hemel Hempstead, Hertfordshire, resulting in the largest peacetime fire in Europe to date. The fire burned for four days before it was extinguished.
Several government departments and agencies asked the Met Office to provide guidance on the smoke plume — including Defra, the Cabinet Office, various emergency services and the Health Protection Agency. Information on the transport and dispersion of the plume provided by the Met Office assisted with decisions on potential evacuation areas and safe approaches for fire crews and played a vital part in getting people to safe locations.
We used sophisticated dispersion models (NAME), together with our weather forecasting model to predict the spread of the smoke.
We used the dedicated Facility for Airborne Atmospheric Measurement (FAAM) research aircraft to take gas and aerosol measurements from within the plume.
Our atmospheric dispersion modellers, based in Exeter, used information gathered to further refine the forecasts and verify our results.
Forecasters and support was also available 24 hours a day through our Environmental Monitoring and Response Centre (EMARC).
As a result of the services from the Met Office the emergency services gained:
clear guidance on how the smoke would move, spread and disperse;
identification of the areas at risk from grounding of the smoke plume;
indications on what the plume contained.
Fig. 1. NAME predicted hourly averaged smoke plume of 0-4,000 m at 1400 UTC on Sunday, 11 December 2005