Weather wise

HOW many times have you come back from holiday somewhere allegedly hot and sunny, only to be told on your return that while you shivered under rainy Mediterranean skies, back home it was dawn-to-dusk sunshine and freak temperatures?

It is no use blaming the Law of Sod; very often, bad weather in one part of Europe is caused by the very same meteorological feature that is providing good weather in another. For example, a summer heatwave is usually associated with a large area of high pressure over Britain or France, bringing light southerly winds, and warm, clear and stable conditions. The same anti-cyclone will bring cold air to much of eastern Europe, Greece and even Egypt.`Freak' weather often sees places which are normally the warmest suffering the lowest temperatures, and vice versa. Thus in January 1987, south-east England froze as continental air swept west from the chill plains of Siberia. Meanwhile, north-east Scotland basked in unseasonably mild temperatures and clear unbroken sunshine.

Very hot, and very cold weather is usually associated with winds from the south and east. In a summer heatwave, therefore, the best place to be is often on the west coast - normally the coolest part of the country at this time of year. Sometimes the normal pattern of a cool north and mild south is accentuated by unusual weather: In the summer of 1976, southern Britain enjoyed temperatures regularly hitting 30C while the Hebrides suffered one of their most miserable summers on record, as low-pressure systems tracking east from Iceland stagnated over the Western Isles, unable to make their way past the heavy bulk of high pressure to the south.