Wet Wet Wet

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  • Figure 1. A cumulative radar image from the 12 hours up to 18UTC on Friday 6th July 2012. The dark blue, black and white colours show the areas that received the highest rainfall totals, such as Yorkshire and parts of the Midlands.

    Figure 2. A cumulative radar image from the 12 hours up to 12UTC on Saturday 7th July 2012. The rain band can be clearly seen across southern Scotland and Northern Ireland, with heavy rain also affecting much of south-west England and south Wales.

    Figure 3. Prince Charles above a swollen river in Hebden Bridge on Friday 6th July 2012, which was badly hit by flooding 2 weeks ago.

    Figure 4. The River Ouse in York, after bursting its banks following heavy rainfall on Friday 6th July 2012.

  • Wet Wet Wet
    07.07.2012 13:04

    With April and June this year being some of the wettest on record across England and Wales, it could be expected that the UK might start to enjoy some dry and fine summer weather. However, the country continues to remain influenced by the weather pattern which has dominated since the start of April, with low pressure systems continually becoming stationary across the British Isles bringing heavy showers or longer spells of torrential rain. Therefore, it is no surprise that the last couple of weeks have seen some significant flooding across many areas of both England and Wales.

    England and Wales received 160.3mm of rainfall during last month, the wettest June month since records began and beating the previous highest total of 157.1mm set way back in 1860. April, May and June combined was also the rainiest since the record books began, with a total of 367mm (or nearly 14.5 inches) of precipitation falling over the three months. All this rain has eased the drought conditions which previously affected much of southern and eastern England, but much of the ground had become saturated by the end of June. This combined with the further deluges we have seen during the first week of July has brought some considerable flooding to some parts of the country.

    Through last week an area of low pressure moved in off the Atlantic and became fairly stationary across southern areas of the British Isles. By the start of Friday, this low pressure system was centred across southern areas of England. The circulation around this system dragged a very warm and humid air mass up from continental Europe, and as this moved in from the south-east and interacted with a frontal system straddling northern England, a very large area of heavy and persistent rain was able to develop (see figure 1). Leeds was the wettest place on Friday, receiving 62mm of rain over the 24 hour period up to 18UTC, more than the usual total for the whole month of July of 51mm.

    Overnight on Friday and into Saturday morning, the heavy rain cleared north and westwards from much of central and northern England. However, the heavy rain then affected southern parts of Scotland, with rain also wrapping back around the low to affect south-west England and south Wales (see figure 2). 38mm of rain fell at Camborne in Cornwall in just 12 hours overnight, with the heaviest rain transferring into Devon, Dorset and Somerset through the morning. Camborne has already had 82mm of rain so far this month, 121% of the usual July total, which is quite remarkable for just one week. Much of Yorkshire and the north Midlands have also seen more than the usual rain expected for the whole of July already. Many of these areas have seen significant disruption and damage due to flooding over the past 24 hours. At midday today (Saturday 7th), the Environment Agency had 142 Flood watches, 73 flood warnings and 1 severe flood warning in effect across England and Wales, with the severe warning for the River Yealme in south Devon.

    Some heavy showers have also developed across central and south-eastern areas of England into this afternoon, causing difficult driving conditions for the qualifying session for the British Grand Prix at Silverstone, Northamptonshire. The drivers during the race tomorrow may also have some wet conditions to contend with at times, as the area is expected to see a mixture of sunny spells and scattered showers, with some of these heavy with the odd rumble of thunder at times. Similar conditions are expected across London for the Men’s Wimbledon final tomorrow, but the showers should become more isolated here through the afternoon with some lengthy dry interludes developing.

    By: Chris Burton