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graphs      CLIMATE-UK.COM'S  REVIEW  OF  THE  BRITISH  METEOROLOGICAL  SCENE
     MONTHLY  SUMMARY
     No. 596     For  AUGUST  2005
           A FAIRLY BENIGN MONTH, APART FROM UNSETTLED SPELL 19TH-25TH
Text Box: Mainly anticyclonic conditions prevailed until after mid-month, although there were brief interruptions around the 4th and 13th. A cyclonic/westerly type took over from the 19th-25th but high pressure returned towards the end of the month. Mean monthly pressure anomaly ranged from +3 mbar at Scilly and Valentia to -1 mbar at Lerwick, and there was a diffluent W to NW-ly anomalous flow over the British Isles.

A flat ridge of high pressure covered the country on the 1st and 2nd, and although many places were dry there were a few heavy, localised showers. Daytime temperatures were near normal, but it was cold at night with 3.3°C recorded early on the 2nd at Aboyne (Aberdeenshire). A rather changeable and cool west to northwesterly flow developed from the 3rd to the 6th but rainfall amounts were mainly small. Rising pressure on the 6th led to the establishment of a weak anticyclone over the UK until the 9th, but the air in the circulation of this high was of polar origin and the weather, although bright, was decidedly cool in northern and eastern districts. Early-morning minima included 1.4°C at Shap (Cumbria) on the 7th and 0.8°C at Braemar (Aberdeenshire) on the 8th, while maxima on the 9th included 11.9°C at Fair Isle and 12.7°C at Rosehearty (Aberdeenshire). As the ridge declined it became warm for a few days, but there were scattered thunder-showers, one such dropping 53mm on Warcop (Cumbria) late on the 11th.

A depression tracked southeast across Scotland on the 13th which was a cool, wet day in most regions but especially in north Wales, northern England, the north Midlands and East Anglia; Hawarden (Flintshire) recorded 45mm. A strong build of pressure across England and Wales resulted in four fine and warm days here from the 15th-18th, the temperature climbing to 29.0°C at Heathrow (London) on the 18th, but Scotland and Northern Ireland were less settled - indeed 45mm of rain fell at Dunstaffnage (Argyllshire) on the 17th. Thunderstorms broke out in advance of an eastward-moving cold front overnight 18th/19th, and heavy rain led to short-lived Text Box: flooding in Leicestershire, Hampshire, and the Isle of Wight. Newtown Linford (Leics) recorded 61mm and Portsdown Hill (Hants) 51mm. Much cooler air in the rear of the front led to a minimum of 2.1°C at Braemar on the 19th and again at Redesdale (Northumberland) on the 20th.

The 21st was fair and warm over England and Wales courtesy of a transitory ridge, but heavy rain in the north and west spread to the rest of the UK on the 22nd. An exceptionally vigorous depression (down to 960 mbar) tracked between Scotland and Iceland on the 24th bringing further rain to the whole of the UK, and gales to Northern Ireland and Scotland where South Uist and Sule Skerry reported gusts to 59kn. Rainfall totals included 59mm at Tyndrum (Perthshire) and 53mm at Shap. The next two days were cool and showery, and northern Britain remained very changeable until the 29th when a gust of 66kn was logged at Scatsta (Shetland). Southern, central and eastern districts, however became fine and very warm, the temperature reaching 25-28°C on the 29th and 30th, and 32.1°C at Northolt (London) on the 31st - the highest temperature anywhere in the UK this late in the season since 1949. Thunderstorms broke out during the day and 46mm fell at Loch Rannoch (Perthshire).

Mean maximum temperature was slightly above average in most regions, but mean minima were slightly below, and the large number of cold nights was in sharp contrast to most recent Augusts; overall it was the coolest August for six years. Averaged nationally, rainfall was about 15% below average and sunshine about 10% above. Less than half the normal rain was recorded in parts of eastern Scotland and northeast England, districts bordering the Irish Sea, and at several places in southwest England, south Wales and the southwest Midlands. The Channel Islands were exceptionally sunny with 322 hours recorded at St Helier (Jersey) - just 11 hours short of the British Isles record for August - but northern Scotland was very dull with only 87 hours of sunshine at Kirkwall (Orkney).