CLIMATE-UK.COM'S REVIEW OF THE BRITISH METEOROLOGICAL SCENE

MONTHLY SUMMARY

No. 590

For FEBRUARY 2005

MILD AND CHANGEABLE TILL THE 12TH, THEN GENERALLY COLD WITH FREQUENT SNOW

Text Box: The late-January Atlantic blocking high soon declined and a mainly westerly type held sway from the 4th-12th. High pressure was re-established southwest of Ireland thereafter, resulting in repeated short-lived northerly outbreaks, and from the 21st the flow veered north-easterly as the anticyclone migrated towards Iceland. The mean sea-level pressure field for February was dominated by high pressure over the Atlantic; an anomaly centre of +23mbar was located at 55N 28W. This was the most "northerly" February over the British Isles since 1889. It was also the least "westerly" February since 1994, and the most anticyclonic since 1993.

A rather mild, mostly dry, but generally cloudy northwesterly flow continued for the first three days, but there were persistent cloud-breaks to the lee of high ground and Leuchars (Fife) enjoyed 43h bright sunshine in the eight days ending on the 3rd. By contrast, Odiham (Hants) recorded a total of 1.1h in the ten days ending on the 5th. The 3rd also brought persistent rain to northwest Scotland, and rain fell more widely over the next two days although the Southeast remained largely dry. An anticyclone over Europe extended its influence over the UK on the 7th and 8th and extensive fog over England was slow to clear in places. Between the 9th and 12th it became windy and very unsettled as a deep depression tracked past Iceland, and there was heavy rain over western hills; Capel Curig (Snowdonia) recorded 51mm on the 9th and 63mm on the 11th, and it became very mild for a time in the south with highs around 13ºC.

A depression crossed Ireland and northern England overnight 11th/12th and, after a maximum of 14.1ºC at St James’s Park (London) during the morning of the 12th, a strong north-westerly brought a sharp temperature drop, snow and hail showers followed, and there was local thunder. This regime continued for the next three


	$Text Box: days, with snow showers increasingly confined to east-coast counties while western regions were quite sunny. A southward moving ridge of high pressure on the 15th/16th was followed by further frontal systems from the northwest bringing occasional rain followed by wintry showers, but a direct Arctic outbreak between the 18th and 20th brought heavy snow showers to eastern districts, especially to Norfolk. The next day the wind veered northeasterly and the remainder of the month was very cold with frequent snow. On the 24th a prolonged snowstorm affected chiefly upland parts of southern Scotland and northern England (52cm at Boltshope Park in Durham with drifts to 6m) but many lowland districts experienced sleet or drizzle. Frequent heavy snow showers affected East Anglia, Kent and East Sussex on the 27th, leaving 20-30cm over the North Downs in east Kent. Notable low minima included -10.2ºC at Altnaharra (Sutherland) overnight 21st-22nd, -11.4ºC at Kinbrace (Sutherland) on the 24th-25th, and -9.5ºC at Redhill airfield (Surrey) on the 27th-28th. This last was the coldest February night in some parts of England for 14 years. Weymouth reported 10.2 hours of sunshine on the 28th under a ridge of high pressure, but further rain and snow spread southwards across Scotland during the last day of the month. The second half of February was the coldest since 1986, but the initial mildness was such that mean monthly temperatures were generally close to or fractionally above the long-term average. Rainfall was above normal in many parts of Scotland, northeast England and Norfolk, but generally below normal everywhere else especially in southern England, and less than 10mm fell locally in Hampshire and Dorset. Sunshine aggregates were very variable: excesses of 30-40% in central Scotland and parts of the West Country contrasted with deficits of 30-40% locally in northeast Scotland.$

TEMPERATURE

SUNSHINE

RAINFALL

Highest and lowest totals

on record for month

on record for month