I see a lot of posts, particularly in the Model Discussion, about "settled" weather. But what, specifically, is "settled" weather about? In my experience it means different things to different people- and most people's definitions don't entirely match the dictionary definition.

Most of us, when we think of prolonged settled spells, imagine those weeks on end of clear blue skies, heat, absence of rain, and sunshine, like in the famous hot dry sunny summers, or the Mediterranean summers. But some people use "settled" as a synonym for "no rain", so perhaps a long dry spell like in August 2003, with a combination of dry sunny weather and dry cloudy weather, would qualify as a prolonged settled spell.

Yet the dictionary definition of "settled" is, simply, not changeable. So, for instance, the two weeks of south-easterly winds, cloud and drizzle that Tyne & Wear experienced in March 1996 were a settled spell by that definition- as the weather hardly changed at all during those two weeks. Or even the week of near-continuous cloud and rain between 25 June-1 July 1997, again the weather hardly changed. Few call those "settled spells" though.

There's also the consideration of whether you're looking at it from a weather type perspective, or synoptic perspective. From a synoptic perspective, rampant westerlies and fronts, with frequent changes in weather type, is generally regarded as a more "unsettled" pattern than a slack low or col bringing sunshine, showers and thunderstorms. Yet the daily weather is the opposite way round- the boisterous Atlantic often results in it being dull and wet, dry and sunny or dry and cloudy for several hours at a time, whereas with sunshine and showers, you often get frequent changes in the space of just one hour.