Gibby:
I know some people don't rate the ECM 10 day Mean Chart but I fine it as good a guide as any and over the last month it has been 100% right in maintaining the look it still has this morning with Low pressure up to the NW and High over Southern and Eastern Europe keeping mild and balmy SW winds across the UK with rain at times. While it's own Operational model has wobbled from this pattern at times the Mean Chart has not wavoured so I can say with some confidence that it will be some considerable time before much in the way of change is likely.
Does the 10-day ECM mean chart ever show any other pattern though? It's what any average of warm, cold and, er, average runs would show, and at that range, with 50 runs to play with, there are virtually always going to be examples of all three.
And as the average UK winter weather is mild, then that 10-day mean chart is always going to verify well. But does that actually make the chart of any use? You could come to the same conclusion just by saying "mild in 10 days' time". Even in the depths of a UK cold spell that is by far the likeliest weather 240 hrs later.
That's why I prefer to wait for the ensemble forecast to update to see whether there are any viable trends away from the average, and try to gauge uncertainty rather than just accept the mean:
http://www.weathercast.co.uk/services/ensemble-forecast.html
Originally Posted by: some faraway beach