Model Output Discussion - Into 2024

[kold weather]

4 minutes ago, bluearmy said:

The ec op post day 7 is for the birds as far as reliability is concerned - no point in debating east based or west based 

we have an Arctic high dropping down through scandi at the same time that a retrogressing Atlantic upper ridge is forcing a trough around the top of it. That trough has warm air in it and it will be meeting the fridgid Arctic air being advected south. Hence it deepens rapidly. But the Arctic high dropping south prevents a classic clean arc and cut back.  I’m afraid there are too many competing factors here. We had a similar run a couple days back which went a bit further west.  if this is the pattern then I’m afraid we’re going to have to wait some time to pin it down - whilst the retrograde ridge and trough could be modelled ok, I doubt that the Arctic high would be at this range. 

These are pretty classic high risk high reward type situations. Obviously if it does end up too far west we at best get some limpet cold coming in briefly like a washed up celebrity on a reality TV show.

If we are lucky and the high  is just right, we get the real McCoy.

[Lukesluckybunch]

We need to get in a position where even a watered down version of what is showing in the extended will do the trick..for me that would indicate a very strong signal for cold!

[That ECM]

The mean gives the general direction. As with all means it doesn’t give the detail. Which I think at this time frame is a good thing not to go looking to hard. 

Edited January 4 by That ECM

[Lukesluckybunch]

2 minutes ago, That ECM said:

The mean gives the general direction. As with all means it doesn’t give the detail. Which I think at this time frame is a good thing not to go looking to hard. 

Do you think of the high was slightly further north at 168...and we lose that shortwave,we could even get a quicker route too cold by day 8..think that's possible..

[That ECM]

6 minutes ago, Lukesluckybunch said:

Do you think of the high was slightly further north at 168...and we lose that shortwave,we could even get a quicker route too cold by day 8..think that's possible..

I think it’s best to to look in detail up to T120 and look at fax charts to see what they are thinking. Beyond I’d just look at nhp and at the moment I’m doing that with a big

[IanT]

58 minutes ago, offerman said:

this chart for me is the absolute pinnacle if this could verify. you have a beautiful tilted high-pressure system tilted in an north east lead direction, sat over Greenland, going up into. Svalbard. Then you have a tilted south-western north east low pressure system sat right over the UK and into Germany and Poland, giving a constant feed of cold and snow picking up moisture of the north sea as well feeding those heavy snow showers into wider areas of snow and troughs from the east
I have seen this set up once before I’m sure it was in 90s definitely seen it in the 80s but in the 90s I remember Francis wilson forecast saying when they expected it to break down and it just went on and and then it extended up and the weather was coming all the way from Siberia all the way down in a South Wesley direction from Siberia to hit the UK was incredible

The Ingham Singularity has been pushed back a day to Jan 16th?

[northwestsnow]

Steady as we go this morning..

Cold dry foggy / frosty after tomorrow ..

High retrogesses ..

We wait to see how the pieces fall..

FWIW I think we are closing in on the retrogression signal - then the real fun begins!!

 

Edited January 4 by northwestsnow

[sebastiaan1973]

A nice tweet. You can find these maps here https://forum.vwkweb.nl/viewtopic.php?f=89&t=4690&p=252615#p252615

[Weather-history]

Manchester ECM 0z 2m temps. Very tight together the ensembles

[Mark wheeler]

Mogreps now clustered below -10 for a while after the weekend. Trending in the right direction, notice the beginnings of a fall again at the end .

[markw2680]

Personally I think many on here are focusing too much on what happens later next week. If the small upgrades keep on coming for early next week there could well be quite a bit of wintry stuff coming off the North Sea spreading quite a way inland. Yes it’s nice to look at what could come later but it’s subject to changes. I fear the run to run panicky poos will kick in 

[Anthony Burden]

Morning all,high pressure holding strong Geffs ensembles showing a short uptick in 850 hpa  for a few days before heading south again just the position of the high pressure over us before hopefully the Greenland high takes over.There is some hints that Atlantic lows may start to try and encroach from the south/southwest but all very speculative at a long range out frost freezing fog and possibly ice days on the cards for the reliable.

[WinterOf47]

33 minutes ago, Paul_1978 said:

It’s FI not F1, which means Fantasy Island, another way of saying ‘beyond the reliable timeframe’ and therefore unlikely to be accurate. 

A lot of people still erroneously put “F1” on here!

Thanks! Guessed it was something like that. It is quite insane that despite the evolution in computing power, the ability to forecast with much precision beyond 5 days has only improved incrementally since the 1980s. I am pretty sure AI will fix this. The simple fact is that despite the humongous amount of variables, the weather today should be predictable from the surface and atmospheric data available 3 weeks ago. I know that with each day there is an exponential increase in the amount of calculations, but still, I think there should have been greater improvements than we have seen.

However, would make these discussions a little more boring!

The GFS is showing a potential streamer for Sunday night into Monday morning for the South east. Could give some in West Kent, South Essex, East Surrey, North Sussex and SE London their first snow of the winter, and the first taster of what will hopefully be a memorable spell. Unfortunately the resolution this far out is not great and I’m not sure how granular they get. In Canada we used to have predicted radar down to 3km and that was great at predicting LES, and a little smudge like we see below could drop 20cm in the space of 2 hours! Now only 4 nights away, so may be the GFS is picking up first signs of some potential activity. Just a subtle shift in wind could kill it off though, or enhance it. Close to the coast would be a mix, but inland on the downs especially, could be snow.

[northwestsnow]

As others have said there might be some potential for some snow showers next week but that's probably one for others with more knowledge ..

Fingers crossed , retrogression is the buzzword and the process doesn't really kick off beyond day 6 so I'd defo stick to the clusters  for now...

Edited January 4 by northwestsnow

[ICE COLD]

Had a quick scan through the models . Haven’t got time to read the forum. The GEM . The pinky purples are in

[EML Network]

Happy 2024: folks, I've been lurking on here all winter for the 15th year in a row. 

Wanted to wait until there was something worth talking about as up until now I've been in the ''how windy is it going to get'' camp and to see if my den in the woods would survive and keep dry (glad to say it did....2 layers of moss, a layer of bracken and a foot of straw around the walls and on the floor helped).
 

Anyhow I wanted to 1: Throw a word of caution (especially to the newer members) and 2 allow myself to get a little bit excited 

For me and the way I see things using the ECM 00z as a guide, IF things unfold as per below and the +192 chart verifys then we are in a really good position from there on out to get what so many of us want to see. 

For me the pieces of the jigsaw don't really start falling into place until we get to +144 as that's when the deep LP system at the southern tip of Greenland heads south and by the time we get to the next frame....

It's sitting close to the Azores and we are in -NAO territory, but the reason I want to throw a word of caution is on the ECM that low travels a HUGE distance from 144 to 168, twice the length of the UK and there are other factors in play that MIGHT not make it such a swift and seemingly unhindered shift.

I know there are other factors that need to be taken into consideration in other parts of the northern hemisphere that others are more knowledgable to talk about, BUT IF +192 verify's there or thereabouts I feel all roads thereafter would lead to a noteworthy cold spell, at +192 that low has now filled, the energy has split and that LP over the Azores is propping the HP over the UK up in such a way that it only has one way to go, being squeezed from all sides leading to either a northerly or easterly. Although it could end up sitting over the UK the whole time, but we'd be pretty unlucky if that were to be the case and we don't know what might come to pass afterwards

I am excited about what I am seeing, but until we get to a similar position to +144 as modelled on the ECM above I am not going to get too excited

[Harsh Climate]

Don't think I've ever seen a GFS average as good at 240h ever!

[nick sussex]

Given the overwhelming support for Greenland blocking that’s now likely to verify .

The question remains where exactly it sets up.

As I mentioned earlier the safest block is the Omega one . The huge cross polar blocking less so.

Earlier there remains some uncertainty with the depth of cold associated with  the easterly . 

Snow wise in the form of showers we don’t have a lot of instability to play with so these won’t be known until nearer the time. With the set up the east and se would see the highest chance .

The T84 hrs fax chart does show that small occlusion close to the far se . The outputs currently don’t make much of that and have it as rain but it is associated with a small cold pool . 

Edited January 4 by nick sussex

[Mike Poole]

ECM clusters this morning, just one cluster to T168, thereafter, T192-T240:

The initial easterly is guaranteed now.  The op is in cluster 3, this is the furthest west as regards the UK.  Cluster 1 differs from the others with a greater amount of forcing on the block from the west of it.  Cluster 1 has 23 members and the block is so strong on the representative member that there is a ‘clear hole’ in the middle of the block where they run out of colours!  This, I would say, is the strong favourite of the three - strong signal there.

T264+:

There’s more uncertainty for this phase as expected, some scope for the block to move around, remaining strong on cluster 1, diffusing a little on the others, but that’s a long way off.  

 

 

Edited January 4 by Mike Poole

[Duane S.]

I can’t stop looking at this chart. It is simply beautiful  

[MattStoke]

Just now, Duane S. said:

I can’t stop looking at this chart. It is simply beautiful  

Streamer city.

[northwestsnow]

Clusters look very good to me  

[Lukesluckybunch]

12 minutes ago, Mike Poole said:

ECM clusters this morning, just one cluster to T168, thereafter, T192-T240:

The op is in cluster 3, this is the furthest west as regards the UK.  Cluster 1 differs from the others with a greater amount of forcing on the block from the west of it.  Cluster 1 has 23 members and these is so little variability within it that there is a ‘clear hole’ in the middle of the block where they run out of colours!  This, I would say, is the strong favourite of the three - strong signal there.

T264+:

There’s more uncertainty for this phase as expected, some scope for the block to move around, remaining strong on cluster 1, diffusing a little on the others, but that’s a long way off.  

 

 

Heights around greenland ...dominating all the way out it seems!..lp to the east and South..perfect setup!

Edited January 4 by Lukesluckybunch
Adding

[Ice Day]

Apologies if they've already been posted, but these are the 216 and 240 ECM Means

 

Despite some nervousness, and dare I say overanalysis of the op day 10 this morning, these means are extremely encouraging.

[Man With Beard]

16 minutes ago, Mike Poole said:

ECM clusters this morning, just one cluster to T168, thereafter, T192-T240:

The initial easterly is guaranteed now.  The op is in cluster 3, this is the furthest west as regards the UK.  Cluster 1 differs from the others with a greater amount of forcing on the block from the west of it.  Cluster 1 has 23 members and the block is so strong on the representative member that there is a ‘clear hole’ in the middle of the block where they run out of colours!  This, I would say, is the strong favourite of the three - strong signal there.

T264+:

There’s more uncertainty for this phase as expected, some scope for the block to move around, remaining strong on cluster 1, diffusing a little on the others, but that’s a long way off.  

 

 

Great update Mike. I note there's a lot of low pressure running into cold air in the D11-D15 period, either over us or just to the south. Whilst that eventually threatens the security of the NW block, it would bring a substantial snow risk into play. All fun and games for the moment though!