By Philip Eden

It had to end sooner or later. Winds from a westerly quarter blew almost without a break throughout January and February, nor was there much change during the first ten days of March either. Last week, however, there was a complete change, albeit temporary, which brought us three days of easterly winds. It is a measure of the competence of weather-forecasting organisations to be able to predict confidently such a meteorological about-turn after a long period of sameness. Most got this one right.

I was expecting to find, when I checked through the archives, that the last twelve months had been remarkably free of easterlies. Last week's spell was the first since the middle of December, and that one only lasted five days. But I had forgotten several lengthy periods last spring, particularly in March and May. Taking the country as a whole there were 50 to 55 days between March 2001 and February 2002 when the wind blew from the east or northeast, below the long-term average of about 70 days, but not by as big a margin as I had believed.

Easterly winds reach their highest frequency during the spring as the strength of Atlantic depressions diminishes. However, the weather associated with these airstreams at this time of the year can vary enormously from one spell to another, and from one part of the country to another. When high pressure is dominant, most parts of the UK are dry and cold, sometimes very cold, with persistent cloud-cover in the east but blue skies and bright sunshine in the west. When low pressure is in control, clouds cover most of the country (although northwestern Scotland can still enjoy fine weather) and there is widespread rain or snow. It is certainly not too late in the season for serious snowstorms - major 'easterly' snowfalls occurred as late as April 14-15 in 1966 when snow lay 15cm deep in parts of Kent, Surrey, Hampshire and Wiltshire, and on March 29 1952 when level snow was 25cm deep over the Chiltern Hills with drifts up to 6 metres.

Last week's spell began with Glasgow and Belfast enjoyed some 35 hours of bright sunshine in four days. By Thursday, however, low pressure was approaching from the south and rain quickly followed, turning to snow in some areas. Although it generally melted as it fell, several higher-level roads in the north Midlands were virtually impassable on Friday morning after several cms of snow accumulated.