Mr Sleet

Although a big improvement in the models for cold, this set up gives us the wishbone effect with snow showers really limited to far northern and coastal areas. For those away from the coasts and in the southern half of the Uk,we'll have to hope for some disturbances running down the country to deliver anything.

Very heavy snow here for a couple of hours, 2 inches down already.We are on the end of the north London streamer!!!

http://cdn.nwstatic..../h850t850eu.png You can see this low pressure forming on the occlusion over Ireland and putting it back onto a more NW/SE orientation, which is what is was progged to do a couple of days ago until the met office switched to more of a N/S (meridional) orientation yesterday. Will it snow in the NW?I should think so, especially Carlisle.

Here's John Hammond with some interesting graphics on the model uncertainty-apologies if posted already. http://www.bbc.co.uk/weather/features/20998895

Indeed,there will still be a lot of uncertainty even on the day of the event in this situation.Going back to the seventies and eighties when this type of event was more common, a straight on south west attack was often repelled if the block was strong enough, what eventually broke it down was an undercut slowing down over France and sucking up some milder air from southern europe, this was mixed in as a south easterly, cutting off the supply of cold air from the east and opening the way for a conventional Atlantic push. Whether that will happen here is anyone's guess! I think your comment yesterday about some people getting a snowy plastering, some getting rain,and some getting nothing, is spot on.

Just seen the BBC forecast for the week ahead which is going firmly with the UKMO output and showing a stronger easterly flow on Wednesday driving snow showers inland. http://www.bbc.co.uk/weather/feeds/21003935

Although the GFS is not everyone's cup of tea at the moment ,it is actually showing a better potential snow event for monday night than the ECM. On the ECM this little wave running south east is almost out in the North Sea. http://cdn.nwstatic.co.uk/gfsimages/gfs.20130110/12/96/h850t850eu.png http://cdn.nwstatic....ecmt850.096.png

The only flaw in this is that the GFS has not backtracked at all in this run, the whole of the Uk is under mild and damp conditions by the end of thursday. The ECM made a large movement toward the GFS today and the GFS has made a slight movement toward the latest ECM.There could well be a decent dollop of snow on monday/tuesday, after that it's a bit up in the air, but there is no strong blocking to the NE/E and the cold pool of air is not being replenished as it is cut off from it's source.So forget the models and go with common sense....thats not going to take much of an Atlantic push to shove it out of the way.

It's because the ECM has clearly moved toward the GFS today-the 12z ECM will be very interesting, I wouldn't bet against a further backtrack.

More like 500 miles !

And GP will be picking the bones out of the carcass of his winter forecast...

Thanks Nick.Yesterday I urged caution with regard binning the GFS, simply because it got a very similar pattern right in early December,against the other models which went for a "Day after Tomorrow" event.Many years looking at these models and a bit of experience in the trade has made me very cautious!I think the GFS does better in these scenarios. This mornings ECM is not anywhere near as good as the past few runs, it's very clear.However, all is not lost, we'll need to wait until Saturday I think, but I'm expecting the GFS type solution to be the winner with a short cold event and back to mild and damp by the end of next week. I'm not sure how significant the SSW is when pitted against what has been a strong Atlantic so far this winter.

Just a word of caution from an old hand-don't dismiss the GFS solution, it got a similar scenario right in mid December when it was out on it's own. I'd say we'll need to wait until Sunday to know for sure.

GFS was the highest verifying model around 11th December when it correctly predicted the return to mild conditions when the ECM and UKMO were going for continued cold.

This looks very much like the climbdown we saw in December, with all the main models progging a sustained cold spell until a few days before the event, when the GFS suddenly had a strong south west flow blasting away any cold after a couple of days,and was proved correct.I suspect the same thing will happen here.