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The fundamentals that will drive the prevailing weather this coming season are shaping up to be quite interesting. In July I provided a hint at an Autumn that starts fine in the Midlands and South but that would be chilly and unsettled in Scotland with wet and windy conditions affecting most of Britain from mid-October onwards. Recent developments on a macro-regional scale point to a more settled and drier season with near-average temperatures, particularly for much of England and Wales. During the last month mean sea-surface temperatures in the North East Atlantic to the west of Britain have recovered and the patch of anomalously chilly water has largely warmed out. Sea surface temperatures off the US and Canadian East Coasts are some 3 to 5C warmer than normal for early August and the same is true of waters in the Greenland and Norwegian Seas. Arctic sea-ice extent remains at exceptionally low levels for the season with southernmost extent running from East Greenland near 75N to north of Spitzbergen and thence to the northernmost tip of Siberia. This would encourage sub-arctic depressions to move eastwards in rather more northerly latitudes than usual and to be more intense than normal due to the effect of a stronger baroclinic temperature gradient in high latitudes and the fact that deeper depressions would be needed to support the stronger Westerlies needed to counter-balance tropical easterlies to satisfy angular momentum budgets when such Westerlies blow even closer to the axis of the Earth's rotation. This would certainly imply a relatively stormy late-autumn period for Scotland. However there are other caveats thrown up by recent developments in low latitudes. Sea surface temperatures are now well below normal off West Africa and there is a tongue of cooler than normal water across the North Pacific around 25 to 30N. The North Pacific north of 40N is some 3 to 4C warmer than normal for early August. More significantly much of the Equatorial Atlantic and Pacific is currently up to 2C cooler than normal. The La Nina phase of the ENSO Cycle has commenced in earnest. The cool tropical waters have resulted (to date) in a very quiet hurricane season in the Atlantic, there has been just one proper hurricane this summer. In the tropical Pacific it has also been an unusually quiet typhoon season with just TWO typhoons so far this summer. This means that the Intertropical Convergence Zone (ITCZ) is rather less convective than usual across extensive longitudes and thus the Hadley Circulation between the subtropical high pressure belt in the Northern Hemisphere and the ITCZ will be weaker than usual across extensive longitudes. This means weaker tropical easterlies and these need weaker (and less extensive) Westerlies in higher latitudes to counter-balance them so as to satisfy Conservation of Angular Momentum laws. This gives a lot more scope for high-pressure systems to persist well into middle latitudes until later in the Autumn. Continued)