Yellow Fog Warning Covers Liverpool Until Monday 11am
Anyone travelling around Liverpool until Monday morning may meet thick fog. The Met Office has issued a yellow warning, says travel may be disrupted, and names the city among the places where fog is expected.
What the fog could do to journeys
The concern is visibility. In parts of the UK it may fall to 50 metres or less, which is why the Met Office lists delays to bus and train services as possible.
Flights to and from the UK could also be delayed or cancelled if the fog is thick enough.
The fog may be densest overnight in rural areas, the Met Office says, including parts of the Midlands, Wales and East Anglia. Air frost is possible there too.
Who is inside the warning
The warning runs from 6pm on Sunday to 11am on Monday. Liverpool is on the list with Sheffield, York, Cardiff and Wrexham.
The area covers most of southern England, with the south-west left out, plus the whole of the Midlands. Smaller pockets of northern England and Wales are in it as well.
Outside it, fog can still form. Niamh Murray, an operational meteorologist at the Met Office, said patchy fog was possible across much of the UK, from the West Country and Northern Ireland to the central belt of Scotland. It would be “just not quite as dense or as impactful”.
Why autumn nights bring fog
Murray spoke to the Press Association about the season. Nights are much longer in autumn and winter, so the air has more time to cool. Colder air sits nearer the point at which it becomes saturated, and fog forms from there.
Some wind is needed too, though not none at all. Murray called the current mix of light winds, clear skies and long nights a “perfect recipe”. If temperatures fall below freezing, she said, the fog can be stubborn to clear the following day.
Rain that could follow
Murray also saw an upside for the south-west, which has had drought in recent months. Severe drought has been declared there and is still enforced by the Environment Agency. She said some very slow-moving rain could bring up to 50 to 70mm, and that rain after the fog could help such areas.
Source: the Guardian