AO-

The only people happy with tonights charts are the ones in Spain who get a significant amount of rain. Where the shortwave first was calculated to track northeast, it now goes Southeast. If it could only go east instead... Then all the problems are solved.

It looks like the GFS is an alcoholic. One crazy run after another with only a few sensible ones inbetween. Also the Swapping of the complete ensemble hasn't been shown by other models. GFS is al over the place and what it comes up with latest is just ridiculous. Let's see what EC comes up with next. The 12z The 06z

Sky Full I wouldn't take this one too literally. Even though it is the right track the GFS is on now, I think the operational is too far (South) east with the block. Notice the EPSs for f.i. Manchester. Personally I expect the block to be more over western Russia/Scandinavia with more of an northeasterly rather than an Easterly flow. This has great implications for the "northerly" flow later on. If the Atlantic goes flat (or shows a southerly jet) a hp over the entire Northern Atlantic may emerge with hp over both Scandinavia and Greenland.

My first impression of the GFS is that it has a more sensible outcome than before and that the bigger picture fits the evolution wrt background drivers more. That it doesn't deliver instantly is a pity, but this is imo the right direction of travel. Honestly I would like the shortwave to track east quicker, but none of the models are showing that. Nevertheless Synoptics to look forward to despite the fact that the cold (especially for Britain) gets a little postponed. The u-turn GFS had made since yesterday shows for me the superiority of EC atm although EC doesn't have nailed it perfectly either. Edit: To visualize the above: for here the operational fits the EPS perfectly whereas for Manchester its kind of an outlier. This shows the complexity of the current situation.

Dennis Lol, 8 cm IMBY. Let's wait and see what happens.

Lukesluckybunch I think this can be resolved "easily" when the shortwave tracks east rather than linger around the UK it tracking northeast. And about that northeasterly: let's hope we dont have to wait until april for that.

sebastiaan1973 Yes, it certainly is. If only there is cold available. Of that I'm not so sure. Mild air is sent towards the Russian border.

Drifter I think there won't be snow. I think the temperature (up at 500mb level) is too high plus an easterly flow. Too little time to generate snow (showers). Pressure is rather high. But those are details at that timeframe.

Even though the EC is a downgrade from a Synoptical point of view, it still fits within the ensemble. It is on the mild side, but 2m temperatures for next week did not downgrade a lot. I think for Britain the difference is much bigger. Nevertheless the cold has been postponed (again). Here is the EPS of tonight compared to the one of yesterday. I would prefer to see another evolution as well, but apparently patience is again the key word. The southerly jet wil get there eventually, which is great for Spain. How it will be up north is still the question. By next week the vortex is probably blown up, but then again, everything has to fall in the right place for winter.

The best possible outcome in the 06EPS is p13. An easterly setting up at day 8.

For London it is by definition an outlier, but only from the 13th onwards. This implies for me that this 06h is a rather unlikely solution.

nick sussex It is not just awful, but also rather unlikely, I suppose. The outcome doesn't make sense to me and is caused by the bias towards deepening of shortwaves/throughs too much. The solution of EC makes more sense, but still the answer could be somewhere inbetween both GFS and EC. We cannot write it off instantly. What the EPS of GFS is concerned, I have seen it Swapping a lot the past few weeks.

Lukesluckybunch Risk/chance of wintry showers in Saturday is high on Icon. After the snow on Thursday/Friday in the Midlands, the wintry showers might head more South.

Mind the scatter at day 5-6 (already) for here. More members going for the UKMO variant? Seems cold next week, but no ice days in the forecast as of yet.

Lukesluckybunch Well, keeping in mind that it is still not sure where to find snow(fall), and given the fact that from Thursday onwards temps at 850 drop below -5 and dewpoints are negative, there could be a good possibility of a snowcover over a great part of Britain except the South. But it is a tricky situation. With hp over Britain afterwards it could be jackpot.

JimBob Over a largely extended snow cover it may be very cold. Back in March 2005 over fresh snow cover here -20 in Holland. The EC is great for Britain I would say. Watching the snow cover adding up with the hp.

Good Morning, It looks like UKMO is the odd one here. GFS worst and EC not so bad, but a lot of mild air is pumped into Europe. UKMO, if it nails it, the best possible option imo.

Harsh Climate Not compared to this morning. It takes about two or three days longer to get the cold in. If anything it is not an improvement.

Worse output of EC tonight. The shortwave is stalling. Not great if you want cold. The EPS for here has downgraded and the mild interlude has extended by three days. It takes too long to turn into cold.

Chesil View It is in line with the other models. Here is the EPS of London this morning. EC and GFS:

Double digits in a great part of Britain next weekend. Also Europe pretty mild to a large extent. It takes a while before a northerly or northeasterly emerges to bring in the cold. The course of the shortwave is wrong if it is cold you want.

Good afternoon, The SSW you are talking about may as well be the final warming of the season before the stratosphere gets into Summer mode. I could be wrong though. What bothers me is that everyone keeps talking about interesting developments beyond two weeks in the future. First it was the second half of February and now it is already the 20th. It certainly is nice to have a hobby, but the double figures we experience now is the reality sadly enough. If I compare the ensembles, they have gotten a tad worse since yesterday. Too much mild air is pumped North before significant cold can arrive. The mild period of next weekend has been extended by a day or two which is not great. That's what is up with GFS. EC in the other hand has improved a tad with respect to cold next week. We still do not have an outcome yet as it is a very complex and delicate situation in which 100 miles makes as lot of difference. I would not put all my eggs in the basket of an SSW as the MJO may as well deliver already next week if one prefers a Scandinavian high over the Greenie one.

The course of the shortwave is questionable in tonights' EC. Shortwave moving northeast where the jet is West East oriented. In this case I would expect the shortwave to move more east given the shape at 120h and the strength of the jet. Important for advecting more cold.

Given the scatter. I think GEM is not really reliable. The worst calculations are possible. Comparing the EPS with both EC as GFS, I don't think it performs well in the long term. Does anybody have an idea what causes this?

winterof79 I would like to put some nuance to this post as it is the result of the calculations of GFS. We see a strong Arctic hp, but it doesn't mean that it will affect our weather. It certainly is nice to see a negative AO, and given the positive signals from background drivers it might as well affect us positively, but some caution should be taken.