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What is a "Bartlett High"?

As the nights draw in, and the yellowing leaves are blown hither & yon in the autumn gales & rain, thoughts of many on this newsgroup turn to ... the "Scandinavian High"! Reason? Well, for those of us living in the 'maritime' region of NW Europe, to get any sort of prolonged cold, wintry weather, we really need a large (in horizontal extent), slow-moving, intense anticyclone - primary centre northern/arctic Russia (probably in excess of 1045 mbar central pressure) - with a strong and persistent ridge extending westwards over Scandinavia - spawning occasional discrete but reasonably 'solid' individual high cells around the periphery; these cells from time-to-time taking over as the primary focus of high pressure.

The air at low levels should be bitterly cold, with low thickness values (indicative of cold air in depth: see  "Thickness: what is it?"). In addition, to produce the required snow, Atlantic depressions / fronts will approach this 'block' (see "Why does the weather sometimes get 'stuck in a rut'?") along latitudes south of 50 degN, attempting to displace the beast and in the process we end up with snow .. or sleet .. or freezing rain .. or blizzards, or any combination of same. Some good examples occurred in the winters of: 1946/47, 1962/63 & 1978/79 as well as January 1940 and December 1981 (not meant to be exhaustive).

However, in recent years (this written in autumn, 2005), these situations have been notable by their absence. What 'high' blocks there have been stay teasingly just too far east and more often than not, a broad band of high pressure extends from the Azores area, east-north-eastwards towards the Biscay / English Channel region - perhaps now & then displaced towards the Alps, as storm upon storm sweeps in from the North Atlantic, hurried along by an often powerful upper jet (see "What are jetstreams?"). Rain, gales and above average temperatures prevail, with any 'wintry' weather confined to brief incursions of Polar Maritime west or WNW'lies, or perhaps a temporary Arctic Maritime blast from the north - which is shunted away as the next surge of mild air hurries in from the west. The apparently semi-permanent belt of high pressure in the 'wrong' place has been christened ... "The Bartlett High", in honour of Paul Bartlett, a luminary of this ng, who used to put his experience of forecasting to the test by publishing a reasoned winter forecast for all to see. As Les Crossan has noted (also a stalwart of this ng), this has come to be regarded as a 'slug' - nothing moves it, not even extracting a pair of dividers and skewering the said beast as it sits dominating any particular synoptic chart!