The warning covers areas in Bedfordshire, Buckinghamshire, Cambridgeshire, Essex, Hertfordshire, Norfolk, Northamptonshire and Suffolk. The Met Office said visibility would be reduced to around 100 meters (328 feet), leading to “difficult driving conditions”. He warned that flights could be delayed or cancelled, and journeys could take longer with possible delays on buses and trains. The warning is in effect until 10:00 GMT.