Mucka

Yeah that may be so, as you say just a worry the latest output would want to go that way instead of reversing the trend. We always get wobbles once the blocking is well in hi res whether or not the cold charts verify.

Twist in the tale tonight, a lot of GFS ensembles want to break blocking down in the mid range. Tense day tomorrow.

JMA is a fantastic chart if you want sustained cold.

The main thrust of cold maybe delayed a little but all that matters is that ECM got through that phase without breaking. From 168 we will see the Atlantic ridge restrengthen and winds slowly back toward East and colder air approach

It's the dreaded shortwaves showing up in the mid term not FI that are the problem. UKMO doesn't show it but the other models do. GEM pushes it South so it doesn't create troughing over the UK or cut off the cold feed and weaken the blocking. NOGAPS is similar to GFS control and several other ensemble members and pushes it through the Atlantic ridge around the mid range. GFS Op holds it off until later so we still draw in the cold before the trough is created. It is just something to keep an eye on the moment, hopefully ECM won't have it and it will have gone by this evenings runs.

GFS was so so in Hi res but GEM shows the way. Wind that on a couple of frames and we would be .

I think some people may be missing the big picture looking for cold from the East, at least initially. Yes it looks as though we will draw in cold dank air from the continent for a while as heights to our West link up with the ridge to our East but as Steve Murr has alluded to and has been very strongly hinted at by the pressure anomaly charts for the period the block is expected to retrogress and the hope is for a cut off Greenland high with the cold coming from the North/North East. From there we may develop another Easterly later and uppers will be much colder across a Continent that will be in the freezer by that time. All that needs to happen is for everything to go exactly to plan and we will be in for a cold snowy second week of December. Edit Maths a bit out there. We should be on course for cold enough for snow a week or so earlier than the second week if all goes well.

That is like wondering why each model produces different output. They all are imperfect in their own way and if the programmers knew how to perfect them they would. Any particular "bias" is debatable but we do have verification stats and know GFS runs at a lower resolution than the Euros.

Depends on how you project the UKMO would go, it is actually much more amplified to the East than GFS which did indeed push more energy NE and have a less southerly tilt to the jet in the crucial medium term so UKMO might better stall the Atlantic later as the trough to our NW drops SE and reinforces the Scandi ridge. http://www.meteociel...44-21.GIF?13-17 http://modeles.meteo...nh-0-144.png?12