A cold week ahead

  • Synoptic situation for Tuesday. Low over the North Sea and high to the west of the UK.

    Dew-point temperatures at 850hPa or 1500 meters on Thursday. The cold air mass will reach Spain and Italy. Dew points of -15C over the UK.

  • A cold week ahead
    25.11.2017 16:43

    Last week, the UK enjoyed a brief spell of mild weather for November. However, it became quite chilly by the end of the week and it looks like next week could be even chillier.

    A brisk south-westerly wind brought mild temperatures by mid-week, with Wednesday being the mildest day of the past week in Hawarden, Flintshire at 16C. Bude, Cornwall reached 15C on Tuesday.  However, on Friday a deep area of low pressure circulating between the Faroe Islands and Norway and a high pressure over the Atlantic established a chilly and brisk westerly to north-westerly air flow over the British Isles. This polar maritime air had some shortwave troughs enhancing the showers in the north and west. Friday night into Saturday was a frosty night with the lowest temperature at Topcliffe, Yorkshire falling to -5.2C and the maximum temperatures not exceeding 10C across the UK.

    The week ahead will have a slow-moving synoptic situation with high pressure to the west of the UK and a deep low over the North Sea. This will create a passage where artic air will move southwards and the air mass will become colder and colder. As you may see on the chart of the left, the dew points for Thursday at 850hPa, around 1500 metres will be around -15C and the tongue of freezing air will move into northern Africa by the end of the week.

    The persistence of this situation will ensure bitterly cold conditions with widespread single figures for the maximum temperatures during the day and widespread frost overnight. However, very low dew-point temperatures also mean a very low content of moisture in the atmosphere. Therefore, it will be largely dry with no widespread snow expected. Just coastal areas exposed to the brisk northerly winds will see wintry showers, potentially falling as snow at very low levels.

    Having said that, on Saturday there will be a risk of a band of sleet or snow moving into England and Wales, perhaps leaving a slushy covering but there is low confidence at this point. Stay tuned to our apps or social network profiles in the next few days to find out if there is potential of widespread snow in the south.

    By: Mario Cuellar