Rain finally on its way towards UK

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  • An heavy rain scene. Photo: PA Wire

  • Rain finally on its way towards UK
    13.05.2017 17:17

    After winter ended with below average rainfall across most of the UK, the month of April and the first part of May continued to be dry, especially over south-eastern areas.

    During the month of April, England and Wales recorded a mean total rainfall of 19.3 mm against an historical average of 59.1 mm. This amount corresponds to just 33% of the total rain we usually see in April. It is even worse if we consider the situation across the south-eastern area only, where the mean total monthly rainfall recorded was of just 5.6 mm, 12% of the whole rainfall we normally record. During May, it looks like the south-east of England has continued to experience dry conditions, with just 5.6 mm recorded at Heathrow Airport until today.

    Having a look at the statistical data, it appears that even though April is not statistically the driest month of the year, it is actually the most prone to very low rainfall total. This is likely to be due to the weakening of the polar vortex that usually happens during springtime, which increases the chance of having blocking conditions with the high pressure diverting the weather systems away from UK and towards other latitudes or, at the opposite, maintaining unsettled conditions for a long time.

    However, the dry conditions should come to an end very soon. The synoptic situation is finally changing across Europe, with no more high pressure to the west and north of the UK, but a vast area of low pressure. There will be no more cold and dry northerly or easterly winds as we have experienced frequently in the past few weeks, but they will become south-westerly, with warmer and humid air pushing north towards the British Isles.

    We have already seen the development of showers across the UK during last week, but the passage of a cold front expected for tonight will open the door to other spells of rain able to bring a much needed rain mostly everywhere over the UK during the next few days. Of course, with such unsettled conditions and the sun strong at this time of year, some rumble of thunder and heavy downpours cannot be ruled out in places, but this is just a small downside in a period like this in which the rain is so welcome.

    By: Alessio Martini