1. 00/XXXX 1 Met Office requirements for fog & low cloud forecasts B.Golding Head of Forecasting Research Met Office, UK

2. 00/XXXX 2 External customer areas Aviation Marine Land transport (Air quality)

3. 00/XXXX 3 Aviation Risk of collision with other aircraft or ground in low cloud or fog Aerodrome forecasts (TAFs, TRENDs etc) –3/9/18hr site-specific forecasts –high accuracy cloud base and visibility –different civil / military thresholds –only very poor conditions relevant at international airports Low level route forecasts: up to T+24 cloud base, icing and turbulence for routes and areas

4. 00/XXXX 4 Marine Risk of collision with other vessels or coast in poor visibility or fog Shipping area forecasts - coastal and fishing vessels Inshore waters forecasts - mainly leisure Ferries Ports Offshore rigs - see aviation

5. 00/XXXX 5 Land transport Risk of collision in dense fog Main routes - need very fine space & time precision Roadside detectors & CCTV used for manual assessment and activation of warning signs Special danger from freezing fog

6. 00/XXXX 6 Forecasters’ requirements Detailed point observations at aerodromes Satellite “fog imagery” –Need early detection of shallow fog –Fog depth and microphysics would be helpful Representative thermodynamic soundings for prediction of cloud/fog formation/clearance Local surface wind, humidity & temperature

7. 00/XXXX 7 Summary Very detailed cloud & visibility observations and forecasts required for aerodromes Distribution of low cloud for low level aviation Distribution of visibility for low level aviation, marine and general public Very accurate fog observations and nowcasts along major roads