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graphs      CLIMATE-UK.COM'S  REVIEW  OF  THE  BRITISH  METEOROLOGICAL  SCENE
     MONTHLY  SUMMARY
     No. 619       For     JULY    2007
                COOL, VERY WET, AND DULL. SERIOUS FLOODING ON THE SEVERN AND THAMES
Text Box: Depressions tracked across the Atlantic Ocean and Europe close to latitude 60 degN almost without a break, maintaining very unsettled weather throughout the month. Sea-level pressure was below normal over practically the whole of Europe with an anomaly centre of -8mbar over southern Sweden. Over the British Isles this was the fifth most cyclonic July in 134 years of records. Cyclonic activity was at its most vigorous between the 1st and 6th, but a weak ridge affected southern Britain on the 7th/8th before a changeable west to northwesterly flow returned from the 9th-12th. Showers were frequent and heavy up to the 6th, and were widely accompanied by hail, thunder and squally winds, with gusts approaching 50kn reported locally; there were also several reports of funnel clouds and minor tornadoes. Stonyhurst (Lancs) recorded 115mm of rain during the first six days of the month. The next two days were quieter with sunny periods, but the morning of the 8th was cold with local ground frost. It was cloudier again from the 9th with showery rain in most areas. Between the 13th and 16th lowest pressure lay in the Southwest Approaches and a warm and humid southerly flow affected mainly eastern England, the temperature climbing to 25.7°C at Charlwood (Surrey) on the 15th, and falling no lower than 17.9°C at St James’s Park (London) the following night. Other areas were cloudy with rain at times. Lowest pressure transferred north-eastwards across the country on the 17th and 18th, maintaining the changeable weather but it became warm briefly again on the 19th with a high of 25.5°C at Gravesend (Kent). A depression which formed over France on the 19th moved very slowly northwards along the Greenwich Meridian on the 20th and 21st to be off Aberdeen early on the 22nd. Rain was widespread, heavy and prolonged, especially in southern England, the Midlands and Lincolnshire, and upwards of 50mm fell over a wide area. Totals in
Text Box: excess of 100mm were registered across at least 2500 sq km of Oxon, Glos, Worcs, Herefs, north Wilts and south Warwicks, with 48h totals of 157mm at Pershore Agric. College and 128mm at Brize Norton. There was immediate short-lived surface flooding, followed by severe flooding over the following week along the lower Severn and the upper Thames. This was the biggest summer rainfall event since 26th August 1986, the worst flood on the Severn between Bewdley and Gloucester since March 1947, and the worst summer flood here since 1886. In Scotland, clear skies and light winds allowed the temperature to drop to 0.5°C at Kinbrace (Sutherland) early on the 20th, and the maximum the next day at Aviemore was just 9.7°C. The next depression tracked along the English Channel bringing heavy rain to southern England on the 22nd/23rd (45mm at Scilly), but northern Britain was fine and Prestwick (Ayrshire) recorded 15.1h of sunshine on the 23rd. A further depression brought heavy rain and strong winds to most regions on the 25th/26th. Southern England was again wet overnight 28th/29th, but the month ended with two days of fair but cool weather as a small anticyclone crossed the country; nights were particularly cold with minima of 2 to 6°C recorded widely. Mean maximum temperature for the month was between 0.5 and 2 degC below the long-term average in all regions, while mean minimum temperature was within 0.5 degC of the norm, and it was the coolest July over the country as a whole since 1993. Rainfall was well above average in most regions except for parts of northern and western Scotland, and five times the normal amount fell in the Pershore district; averaged nationally it was the wettest July since 1936. Sunshine duration was above normal in parts of western Scotland, Northern Ireland and locally in the south Midlands, but it was well below average in northeast Scotland, northeast Wales and Lancashire; over the country as a whole it was the dullest July since 1998 and locally in northeast Scotland it was the dullest on record.
                                                                                                                                               
                       TEMPERATURE                                SUNSHINE                             RAINFALL