Kasim Awan

That chart to me shows a lack of forcing and lack of cold air nearby.

No need for that. Weather is not black and white both options are shown so both are possible. Where can we see this?

See the ECM12Z.

I think the drop of the PV into our side of the NH is quite likely now. The placement of it will depend on the position of the high, if it drifts too far N over Greenland a cyclonic circulation will develop close to the UK which will push cold to our North keeping us in Atlantic air. If the high is slightly further South this wont happen and cold air will more smoothly advect which is still a distinct possibility which I have not discounted.

Personally I think a west based -NAO is becoming increasingly likely. It makes sense given both the strong signal for retrogression and relatively strong heights to our South.

Energy at 500mb jet coming up from the South here. This is the worry if heights are still relatively high over Europe then there's a good chance the cold will be pushed NW of the UK with some jet energy deflected up from the SW.

The solution of strong retrogression to Greenland met with a push of energy from the SW is gaining traction. Around 1/2 of GEFS went this way and so does ECM, this makes it challenging to advect cold South however would set up a battle ground over the UK which could result in snow in places.

I think you have mistaken a lot of my posts for my opinion when in fact they are just reflecting what the output is showing. Atleast the ECM has heights a little lower over Iberia region.

A couple of days ago apparently the chance of this high sinking was near 0.

A third each.

The other option is dragging up mild air from the SW if the retrogression sinks SE. If the retrogression takes too long, I can easily see low pressure spinning out to the SW of the Azores high reinforcing the UK high which then makes it less likely to retrogress hence increasing strength of the high etc etc in a perpetual loop.

I'd say a cold North Easterly from a central Greenland high, near normal temperatures from a west based Greenland high & mild from a Mediterranean high are equally likely options at present.

Not going for mild just saying it's an option. So many in here have the tendency to muddle words.

We can't also discount a push of milder air from the SW.

We shall see but I think with that mindset you're setting up for a potential massive dissapointment. Those same 100,000,000 super computers have been wrong so many times at that range.

Personally I don't understand why so much weight is being put on mid January.We can't get the next 5 days into 50% confidence so my confidence on this is very very low.

It's day 5 aswell.

It's the biggest driving mechanism of our weather now so comparing it to 1 factor in a global pond is not helpful.

We could quite easily end up here - if we end up with a UK high the Azores to our South will be under a perpetual strengthening motion and resulting very mild uppers.

Imo unfortunately there is nothing speculative about the Azores high being a severely limiting factor in this cold spell.

This I fear is the place we could be heading - GEFS00Z is significantly flatter South of Greenland day 8.

Things haven't gone wrong because the posts have been shifted to day 10-12 whereas a few days ago an easterly early next week was almost the favored scenario and now it is less likely. Although there is significant support for big retrogression days 10-14 there are big barriers in our way, firstly a synoptic pattern that significant is laden with the usual pitfalls. Secondly we have to factor in the recent tendency to promote heights in unfavorable areas as we approach day 1. Still it is a noteworthy chance and has all the positive signs associated with it aswell, such as background factors like AAM and good consistency. So a balanced view would say there is a significant chance but it is far from nailed on and will likely result in lots more twists and turns as models break down complex mesoscale interactions in the medium range.

I see things from every angle, I understand that the weather is a result of a complex set of interactions which themselves need closely analysing. The up and down nature of my posts is related to seeing a different angle each time and noting the significance of each synoptic driver. Today for example we have seen an increase in Azores heights again. It's very clear within the GEFS that pressure has risen a good 25-30% over the Azores region. This is a significant barrier in terms of advecting cold south and producing easterly flows. A few lines of code would sort it and we wouldn't have to tolerate the downgrades.

The thing is they are there and they're causing significant issues in advecting cold south. Had heights over the Azores been slightly lower we'd have been looking at a very cold easterly early next week. This is indeed what was modeled a few days ago until the time frame came within scope of models being able to accurately determine the inflation of the hadley cell and shunt out the possibility of an undercut.

Not changed my mind on that the first attempt is most likely to produce a UK high & second is more likely to produce a cold northeasterly. This was a statement that the delaying of very cold charts is not a positive.