THE CFS has been providing some confusing solution to the December forecast in recent days. It's been all over the shop with NAO and AO predictions, rowing back from it's stable ideas for the last few weeks of a predominantly negative set of indices.

But the latest run looks a little more coherent.

The 500mb anomalies call the trough over Europe with the higher heights to the northwest showing the flow is likely to be mostly from a colder northerly quadrant.

This would place higher pressure to the northwest, as the forecast pressure anomaly shows ... just look how much lower than average pressure is over Europe...

Now given that, you'd expect temperatures to be cold in the UK. But the fact that the CFS goes nearer average suggests that although cold is likely, there could be times when the flow flips to the southwest, bringing more milder conditions for several days. This is a pattern we can buy into.

So a fli-flop month, perhaps 10 days of mild, 20 days of cold.

(Thanks to tropical Tidbits for the charts)