What you say is true. I remember in the last week of January I said, based on the charts, it couldn't be a special winter. That was because there were no hints for 10 days after that of cold and as there would only then be three weeks of winter left that would have to have been of epic proportions to make the winter memorable. Nevertheless I saved that days London 850hPa ensembles and at ten day on they aren't even vaguely close to reality. As ever there was total uncertainty but the middle of next week was generally mild or very mild, no hint of what could be the snowiest spell of the winter. I have done this exercise a few times now over the years and it has rarely been right at T+10-14 days and often it is about as opposite to the prediction it could be. So it can always give decent cold spell at more than 10 days whatever the charts say.
What we do have to accept is that climate change is kicking in and they will be less frequent anyway as the stats clearly show.
Originally Posted by: fairweather