Model Output Discussion - Into Winter

[tight isobar]

Classic Situ developing via gfs 6z cold entrenchment, hold steadfast . Aided via stubborn blocking!… A big  extension of cold- and sometimes a hint of colder infer to come- develop!..

Edited November 28, 2023 by tight isobar

[Severe Siberian icy blast]

1 hour ago, TSNWK said:

Thanks.. I was going to pose the question where to now after next weeks currently progged breakdown…which has broad support across the operations/ with the same trend showing in the clusters now…probably leading to a couple of weeks at least of mobility?

I’ve read thecteleconnections are postive for late December? Why should we believe them when they were wrong in summer and were not aligned to this current high pressure dominant chilly spell.

The say a day is long time politics.. Jeeze it’s a lifetime in model viewing

 

One morning of a breakdown been a wk away still and suddenly we're going into a two week period of zonality this place is hilarious.. we have had cross board agreement of very cold hair the last few days but now it's definitely right 

 

[Ali1977]

Just now, suxer said:

Jeez look at germany

Fair point , 100 percent snow cover in the first week of Dec is exceptionally rare I’d say!! Give us an easterly please

[MattH]

The dominance of the blocking patterns is quite impressive, in the short-term, reinforced by a number of wave breaks over the N Atlantic, but the 'writing is on the wall' for a breakdown further into December, but probably not before the first week of December is done with, so a cold start to winter it is.

Anyway, a few slides and thoughts below as part of a wider document/analysis of mine...

[TSNWK]

2 minutes ago, Severe Siberian icy blast said:

One morning of a breakdown been a wk away still and suddenly we're going into a two week period of zonality this place is hilarious.. we have had cross board agreement of very cold hair the last few days but now it's definitely right 

 

Absolutely.. it’s all part of the fun and games in here.. guilty as charged my lord!

[SilverWolf]

25 minutes ago, Ali1977 said:

The little system showing from the SW on the icon on Sunday has some support 

Now that does look like a repeat of last December! But as we said yesterday that wasn’t expected even hours before the event.. 

[northwestsnow]

OK thanks Matt for the update..

Absolutely no need to be despondent this morning .

We've a week of wintry weather ,enjoy the markets ,or enjoy some walks if you have rural settings ,heck maybe the Xmas shopping!

A breakdown is almost certainly coming but it's rare to get a week of cold weather here in the UK and hopefully this is just a starter.

[BartyHater]

20 minutes ago, northwestsnow said:

Fascinating 6z..

144

Indeed, but it only creates a very temporary slowing of the now almost inevitable breakdown. My main hope is when the Atlantic does break through we don’t go back to raging zonality across our latitudes, because after a wet summer and a very wet autumn, we really do need a drier than average month or two if possible…and I think we deserve them.
 

[MATTWOLVES 3]

You know what I love about this forum?

A cold spell as just started and hangs around for at least a week...the morning runs look poor for extending it but the obituaries have already been written for its demise...on the back of model data which is changing more often than money at a  tax office.

This is like a load of family coming round your house one day and saying to your Mother...we are really sorry over the passing of your Huaband,he was such a nice man and looked like he would go on for ages! And ya mom turns round and says....what the bloody hell are you talking about,he's sitting in the living room with his feet up watching Corination Street!

The models can get it wrong...they can get it wrong multiple times a day.

The next week is going to be seasonal with plenty of Frost...let's rejoice with our Xmas shopping when we wipe the ice of our windscreens. Next week could always change for the better.

[AdrianHull]

2 hours ago, Nick2373 said:

No knee jerking at all, just a clear trend that's been showing for a gradual return from around the 05th/06th December for something of a normal set up. Just like a trend was showing for the current cold spell. 

Not quite what I'm seeing. Latest runs have us still have us in below average.

EBS and flows and all of that .

What happens past this weekend is is impossible to predict. Lots of ups and downs until then

 

[Chesil View]

Best way to look at this is as follows I think.  We have a bonus early cold spell in a winter that looks primed for blocking episodes the further we go into it.

Also ask your self which classic winter ever really started in the first week of December and lasted all the way through.

The winters of legend certainly didn't. 

Take this wintry bonus and wait a little longer  for winter proper to get under way.

[Mcconnor8]

Just now, Chesil View said:

Best way to look at this is as follows I think.  We have a bonus early cold spell in a winter that looks primed for blocking episodes the further we go into it.

Also ask your self which classic winter ever really started in the first week of December and lasted all the way through.

The winters of legend certainly didn't. 

Take this wintry bonus and wait a little longer  for winter proper to get under way.

I'm also happy it is cooling down SSTs around us to likely below average after this spell is done which should help with marginality down the line especially for people on the coasts like ourselves, airmasses this early in Winter will always struggle to produce snow so never had high expectations yet especially with all the background signals pointing to a back loaded Winter cold wise.

[Jacob]

[Battleground Snow]

I do still think the gfs in particular is draining the blocking away a little too fast still.

If you compare it to the very consistent arpege,

If and when the Atlantic does break through I think it's going to take a couple of attempts to break through the entrenched cold

[Downburst]

@MATTWOLVES 3 I've just ordered these for the coming week, amazon prime 

 

Not putting a downer on it, but if and when the westerlies return we don't want to see in my opinion and preference a southerly tracking Jet. So happy to see this as if we must have SW I want the normal track and be gone with you low pressure as quickly as possible up to Iceland, you can get nice December days between fronts. Then await the mid to end month period for something better

[TSNWK]

12 minutes ago, Downburst said:

@MATTWOLVES 3 I've just ordered these for the coming week, amazon prime 

 

Not putting a downer on it, but if and when the westerlies return we don't want to see in my opinion and preference a southerly tracking Jet. So happy to see this as if we must have SW I want the normal track and be gone with you low pressure as quickly as possible up to Iceland, you can get nice December days between fronts. Then await the mid to end month period for something better

But... this approach introduces risk of losing all the cold to our north east that took a month to build up.. 

Rather a southerly jet keep it cold in scandi and small as it might be the chance small sliders into cold air over us  

Edited November 28, 2023 by TSNWK

[sebastiaan1973]

Excellent setup for disturbing the stratosphere. 

[carinthian]

2 hours ago, carinthian said:

Morning all. In the shorter term out to next weekend some extensive early winter cold about . In that period , the models have upgraded the cold this morning with some low values being shown across the British Isles and widely across much of Europe. It is now we can look for snow potential across The British Isles , probably of the convectional and trough formation type generated over the North Sea. Whether the longer term charts bring in the milder Atlantic flow as being shown this morning occurs or not , I think, for many just enjoy the seasonal offerings over the next 5/6 days or so and then see what develops ?

C

Just to highlight the uncertainty for next week. The second chart from GFS (06 run ) already differs from earlier output (00t) first illustration below. The jet not as aggressive on latest run and hints at further amplification over Eastern Atlantic. Think at this stage we may well be looking at a extension to European cold spell. The longer it gets established the harder to shift but as always 10 days is a long way off. So for you lot back in Blighty enjoy the winter sunshine and long frosty nights for rest of this week. Any snow will be a nice bonus and good to see the first advisories being issued for the NE.

C

[mfhblue]

47 minutes ago, SilverWolf said:

Now that does look like a repeat of last December! But as we said yesterday that wasn’t expected even hours before the event.. 

It does indeed. I recall posting a chart almost identical to the one below a day or two before last year's "event". A little low forming in the South West and trundling along the channel coast. If I recall correctly, GFS kept toying with the idea and then dropping it again. Could history be about to repeat itself?

[TSNWK]

Sadly 06z was right at bottom of pack for middle of next week..so I guess that delay in the atlantic coming in that was shown on 06z is unlikely..

[TSNWK]

6 minutes ago, carinthian said:

Just to highlight the uncertainty for next week. The second chart from GFS (06 run ) already differs from earlier output (00t) first illustration below. The jet not as aggressive on latest run and hints at further amplification over Eastern Atlantic. Think at this stage we may well be looking at a extension to European cold spell. The longer it gets established the harder to shift but as always 10 days is a long way off. So for you lot back in Blighty enjoy the winter sunshine and long frosty nights for rest of this week. Any snow will be a nice bonus and good to see the first advisories being issued for the NE.

C

Please see post on ensembles. 06z right at bottom of pack   so at best is 20/1 outsider

[northwestsnow]

Wow that's a big signal  

Hope that's wrong !

[offerman]

43 minutes ago, Jacob said:

Hi Jacob
The only problem for people south east of Wales, Northeast, Somerset, Wiltshire area with snow coming in from the north-west is quite often the Welsh mountains, suck the life out of any moisture, and they get a dumping, and we get residual cloud and the odd flurry. 

[feb1991blizzard]

1 minute ago, TSNWK said:

Please see post on ensembles. 06z right at bottom of pack   so at best is 20/1 outsider

6z is not at any point at bottom of pack - its in one of 2 distinctive clusters before jumping into the mild cluster very quickly.

[Lukesluckybunch]

3 minutes ago, northwestsnow said:

Wow that's a big signal  

Hope that's wrong !

What's that saying we need more reds and green in there?

Edited November 28, 2023 by Lukesluckybunch
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