Fog shrouding swathes of UK likely to disrupt transport early this week

Thick fog will shroud much of the southern half of England, the eastern half of Wales and most of Northern Ireland throughout the early part of the week, forecasters have said, as commuters are told to expect delays.There was disruption to flights at Heathrow airport on Monday, while an incident involving 30 vehicles closed a major road in Kent on Saturday evening.Niamh Murray, a Met Office operational meteorologist, said current weather conditions were the “perfect recipe” for fog. “With autumn and winter … we get much longer nights, and that allows temperatures to fall away,” she said.Fog in Liverpool city centre on Monday. Areas of England south of Manchester have been issued a yellow weather warning. Photograph: Peter Byrne/PA“We get a longer period of cooling and also the temperatures are much lower, so they’re much closer to the temperature that we need for the air to become saturated and therefore form fog.“Another thing that we need to form fog is quite light winds, not absolutely no winds. We just have the perfect recipe at the moment – light winds, clear skies, long nights – to allow that fog to develop. And particularly if we see the negative numbers [the temperature in degrees Celsius], it can be quite stubborn to clear the next day.”Forecasters issued yellow weather warnings, the least severe, for Monday in areas covering: most of England south of Manchester, with the exception of Devon and Cornwall; eastern parts of Wales, including Cardiff; and most of Northern Ireland, with the exception of Belfast. Visibility could be down to 50 metres or less in some places, with delays to bus and train services possible and a chance of flight cancellations.Dense fog on Wimbledon Common, London, on Saturday. Photograph: Amer Ghazzal/ShutterstockThe affected area is likely to shrink to the Midlands, Staffordshire and Cheshire in the west of England on Tuesday, and eastwards across most of Yorkshire, Lincolnshire and East Anglia.On Monday morning, a spokesperson for Heathrow said: “Overnight fog has affected visibility on roads around Heathrow and conditions may continue into this morning. If you’re travelling to the airport, please allow extra time for your journey. We advise passengers to check with their airline before leaving home and to drive with care.”An 30-vehicle incident in foggy conditions on Saturday left two people seriously injured and closed the M20 in Kent between junction eight and nine near Maidstone.Drivers have been warned to lower their speed to avoid collisions amid the thick fog. Photograph: Geoffrey Swaine/ShutterstockEdmund King, president of the AA, previously said: “Fog can transform a familiar road in a matter of minutes, so drivers need to be prepared to adapt their speed and leave more room between themselves and the vehicle ahead.“One of the biggest mistakes is simply following the rear lights of the car in front. It can give you a false sense of security and means you may be travelling too close to react safely if that vehicle suddenly stops. Ultimately, there’s no prize for arriving a few minutes early. Give yourself extra time, slow down and drive to what you can actually see ahead.”