Thunderstorms hit the south-east of England

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  • Fig1. Total number of lightning strikes recorded at 0800 on Monday (29th May 2017) morning from the from the MCS that passed through the English Channel.

    Fig2. Lightning strikes from thunderstorms tracking north-eastwards across London and into Essex on Friday 2nd June 2017.

  • Thunderstorms hit the south-east of England
    03.06.2017 15:24

    The first event occurred last Sunday night into bank holiday Monday, which saw a mesoscale convective system (MCS) working north-eastwards from northern France, through the English Channel and skirting the far south-east of England. An MCS is defined by NOAA as “a complex of thunderstorms which becomes organized on a scale larger than the individual thunderstorms, and normally persists for several hours or more” (https://forecast.weather.gov/glossary.php?word=MCS, 2017). The MCS on Sunday night into Monday produced an impressive display of lightning for anyone along the south-east coast of England with some strikes venturing further inland towards London. In fact by 0800 on Monday morning a total of 80,000 lightning strikes had been detected with the most intense part of the storm producing over 700 strikes per minute (shown in the diagram on the left). The storm did cause some damage as it passed through with one house in Kent being struck by lightning causing the roof to set alight, thankfully no one was hurt. A truly impressive night for anyone who is a fan of thunderstorms, not so though, if you are a fan of sleep…

     

    The second event in the south-east occurred on Friday with some home grown thunderstorms developing through the afternoon. Unlike Monday, these thunderstorms were mainly independent and lasted a couple of hours. However, they did pack a punch as they developed to the south-west of London before tracking north-eastwards over London and into Essex (as shown in the diagram on the left). The storms that did develop gave some very intense rainfall over a short period of time, Kenley in south London saw 9mm in an hour (between 16:00 and 17:00) and Shoeburyness, to the east of Southend-on-Sea saw 12mm in an hour (between 17:00 and 18:00). The storms did cause some disruption to the Friday evening rush hour across London with some flash flooding in train stations and tunnels. It was welcome rainfall for gardeners, albeit another intense and very brief downpour.

     

     

    Outlook for the coming week

    The theme for the weather over the coming week can be summed up as “typically British”, as we move into the start of the British summer. There has been a lot of dry, warm and sunny weather around in the last few weeks. However, Monday does not follow trend, two areas of low pressure will bring unseasonably wet and windy weather across the British Isles. Although Monday may well start off fair in eastern areas of England, it will turn increasingly unsettled as rain pushes in from the south-west. This will lead to a rather dull, wet and windy end to Monday and day on Tuesday. The heaviest of the rainfall looks likely to be across western areas stretching from the hills of south-west England, into Wales, north-west England and western parts of Scotland. It will also be windiest across western and south-western areas of the UK where gusts could reach up to 50mph.

     

    By mid-week though there is somewhat of a more settled interlude as the UK sits between two areas of low pressure, one to the north-west and the other to the south-west. The latter will work north-eastwards later on Wednesday and into Thursday, polling day. This will mean that most of Wales and England can expect a changeable day in terms of weather when casting your votes during the day. Many places will see showery rain with longer spells of rain developing at times, especially in the west. Scotland seems to escape the worst of the conditions with largely dry conditions with variable cloud and sunny spells. The unsettled theme looks likely to continue into the Friday and the weekend as further areas of low pressure spread in from the south-west bringing spells of rain and strengthening winds to much of the UK. Not great if you have outdoor plans this week or if you were looking for some summer sun and heat.

    It is worth bearing in mind that at this stage, although there is good model agreement of a more unsettled week for many. There are still possibilities for small changes through the week. To keep up to date follow us on Twitter or Facebook to get the latest news on the weather for next week.

     

    By: Tom Whittaker