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graphs      CLIMATE-UK.COM'S  REVIEW  OF  THE  BRITISH  METEOROLOGICAL  SCENE
     MONTHLY  SUMMARY
     No. 629       For     MAY      2008
         VERY WARM;  DRY AND SUNNY IN THE NORTH; A DULL, WET LAST WEEK IN THE SOUTH
Text Box: High pressure lay to the north of the UK, either in the Iceland/Greenland region or over Scandinavia, throughout the month. Pressure was frequently low over mid-Atlantic, and during the last week over Biscay and France. The main sea-level pressure anomaly centres were +8mbar in the southern Norwegian Sea and -7mbar to the west of Biscay, resulting in a marked east to south-easterly anomalous flow over the British Isles. In fact, this was the most ‘easterly’ May in 136 years of records. The early-morning of the 1st was wet over Scotland (the rainfall credited to 30 April) as a vigorous depression moved away northwards; a very warm but cloudy south to south-easterly airflow developed over the next few days, and there was further rain at times chiefly in western districts, but in eastern and central England it was largely dry. A long period with maxima widely above 20°C began on the 3rd, while several nights were unusually mild too. Most parts of the UK were very warm and sunny from the 5th until the 13th as high pressure remained slow-moving firstly over the North Sea, and latterly near northern Scotland. The temperature climbed above 25°C somewhere in Britain daily from the 7th to the 13th, reaching 27.3°C at Herstmonceux (Sussex) on the 10th, 27.5°C at Malvern (Worcs) on the 11th, and 26.9°C at Lee-on-Solent (Hants) on the 12th. The warmest nights were those of the 9th/10th and 10th/11th, and on the latter night the minimum at St Catherine’s Point (Isle of Wight) was 16.6°C. Norwich reported seven consecutive days each with more than 14 hours’ bright sunshine ending on the 12th, and the total for 1st-15th there was 165 hours, an average of 11 hours per day. From the 14th to the 23rd pressure remained high to the north of Scotland, with a cool east to north-easterly flow covering the British Isles. Central and northern districts remained dry and mainly sunny, but there were occasional thundery outbreaks in southern England and south Wales, notably between the 14th and 17th, and St Mawgan (Cornwall) collected 41mm overnight 14th/15th. The month's lowest maximum of 8.2°C Text Box: occurred at Carter Bar (Roxburghshire) on the 17th, and there were sharp frosts at night especially in Scotland and northern England, and at Kinbrace (Sutherland) the temperature fell to -5.0°C early on the 18th and -6.2°C on the 19th. The north-easterly flow strengthened markedly between the 24th and 26th as a vigorous depression became slow-moving in north Biscay; on the 26th gusts to 64kn were recorded at Mumbles (Glamorgan) and 53kn at Pembrey Sands (Carmarthen). Heavy rain spread northwards across southern and central parts of England and Wales late on the 24th, and there were repeated bouts of heavy rain over the next five days including falls of 40mm at Thorney Island (Sussex) on the 25th and 39mm at Liscombe (Devon) on the 26th. Manston (Kent) collected 121mm in 84 hours between the 24th and 27th, and a further 25mm on the 29th. On the evening of the 29th thunderstorms broke out over the West Country leading to short-lived but severe local flooding, notably in the Crewkerne/Ilminster and Bruton/Castle Cary districts of south Somerset; 70mm fell in less than 4 hours at Batcombe. Rain finally reached Northern Ireland and Scotland on the 28th, ending a 23-day rainless period in several places here. There were further outbreaks of showery rain with local thunder, notably in southwest England, on the 30th and 31st. Mean temperatures were 2 to 3 degC above normal over much of the UK, apart from eastern Scotland and northeast England where the excess amounted to 1 to 2 degC. As measured by the Central England Temperature, it was the warmest May, with the exception of 1992, since 1848. The heavy rains of the last week ensured that all southern districts were wetter than normal for the third consecutive May, but northern England, Scotland and Northern Ireland were all exceptionally dry with monthly totals of just 5-10mm reported from a number of sites. Sunshine duration was 50 to 80 per cent above normal in the north and west of Scotland, but up to 30 per cent below in the English midlands; monthly totals ranged from 304 hours at Fair Isle to 135 hours at Coleshill (Warwks).