Winter Approaching: Forecast and Model Discussion Commentary

[Met4Cast]

 Don

Mid-late December looks to be the broader timeframe where we could see some amplification, that hasn't changed in my mind, it's still beyond the scope of NWP outputs.

[Don]

30 minutes ago, near northampton said:

you seem  to make a fundamental assumption that everyone on this thread is looking for cold snowy weather , not everyone is

Just like not everyone is looking for hot weather during summer?

[joggs]

I don't know why some people are surprised at the output downplaying the short cold snap.

A week/10 days ago,the pv was not forecast to develop that deep over Greenland!.

The moment it does happen in the nearer time,there's only one way the output is gonna go........

Nearly always,a flat jet and a westerly regime.

Until we get something (forget the forecasts for three weeks ahead) that shakes the pattern up,we will hardly benefit. That's the truth.

I've found accepting this,makes things alot easier.

 

[DavidS]

Days 6 - 10 on the GEM. It could be a whole lot worse

.

[johncam]

The GFS mostly westerly and at times on the mild side right to end. Not holding much hope for rest of DEC. 

[Lukesluckybunch]

27 minutes ago, DavidS said:

6 - 10 on the GEM. It could be a whole lot worse

We are in quite a good position at 240 with a strong hp over the uk,eventually that could shift west to open the floodgates from the north,at the very least it looks dry and chilly 

Edited November 30, 2024 by Lukesluckybunch
Adding

[Legend.Ice]

It's better to stay in the cold sector than sector 

[TSNWK]

ECM not completely without interest.

[Jordan S]

Morning,

I know I mentioned this feature for Tuesday briefly yesterday but thought to take a closer look today..

Just something to keep an eye on if you are on high ground in particular later Tuesday, possibly more-so from just an interest point of view rather than any potential disruption, the risk of some falling sleet/ snow for mostly high ground in parts of the Midlands, but more especially parts of northern England and parts of Scotland away from coastal areas for a short time, most likely rain further south but in any possible heavy precipitation there may be the odd few flakes mixed in on the Cotswolds for example but that's really it I think.

Could be some local snow accumulations to mainly high ground of northern England, and more especially parts of Scotland for a time.

Low pressure centre on the southern portion of this weather front and higher pressure to our east delays the clearance of this precipitation but intensity lessens rather quickly during latter part of Tuesday night.  

Less cold air will make it's way in though thereafter turning much of any wintry precipitation that is still present along the front to sleet/ rain before and in few places as it fizzles out and slips to our south/southeast by Wednesday daytime.

 

Again an unsettled latter part to the week with strong winds in places, and probably again trending a bit colder in the north after the initial milder temperatures of Thursday-Friday time.

Will update again on Monday.

Edited November 30, 2024 by Jordan S

[Dennis]

7-9 dec i see as a first key point

ec took a major shift from yesterdays chart --- from westerlies and strong zonal to a more blocked idea NAO+ now to a NAO-

see 29 and 30nov  chart

 

Edited November 30, 2024 by Dennis

[That ECM]

1 hour ago, johncam said:

The GFS mostly westerly and at times on the mild side right to end. Not holding much hope for rest of DEC.

You have nearly given up on December based on the gfs?  Is control right? Probably not but why dismiss it? 
 

T240 ecm is the high going to sink? Why dismiss it? 

[TSNWK]

 That ECM thanks. On both those panel it’s great to see energy below us for once….

should on paper prevent the high sinking further…a holding position maybe until the next amplifier wave heads towards us.

[northwestsnow]

EC v good this morning ..

Into FI something interesting too

[carinthian]

Morning all. Quite chilly looking models for next week across Blighty , especially next weekend. Nice seasonal weather for the many Christmas Markets and yes the forecast snow models looking good for Alpine snow as the ski-ing season gets underway. Enjoy your weekend.

C

[LetItSnow]

30 minutes ago, That ECM said:

I feel like it's good to see weakened pressure to the south. All too common a feature of the large teapot is intense high pressure systems residing over southern Europe/north Africa, then the natural flow of things locks in a mild pattern. However, there's always the possibility of movement when the pressure is taken away to the south. By no means a guarantee of anything (see January/February 1999 for a fail). This run would probably be pretty cold in the south with harsh frosts at times after an initial blast then high pressure.

Not seeing a write off to winter yet. The first half of December usually tends to be a time when building blocks are being set up for the rest of winter. Not often prolonged cold starts now and goes all the way through. Plus things change so rapidly in the models that if a more substantial cold spell is lurking around the 15th period then it most likely would not appear yet, let alone around Christmas.

[Lukesluckybunch]

17 minutes ago, northwestsnow said:

Into FI something interesting too

Wow that is some serious blocking out west,cold air already into scotland

ECM mean day 7

[Coldie24]

 TSNWK it’s not a bad thing sending milder air to Iceland. Many a cold spell have begun that way.

[clark3r]

I don’t normally take much notice of FI charts, but I am liking the trend FI ECM is good today, wondering if we are going to get some proper winter around mid December! 

[northwestsnow]

Suspect the clusters might be decent this morning....

[damianslaw]

I think the main interest at present is the projected build of very strong heights to our west around the 9th Dec, over 1040mbs.. not to be sniffed at, if such a feature develops it won't be easily pushed aside even by a strong jet a la GFS0z- which to me looks far too progressive this morning. ECM holds it in play and looks more plausible in how it handles it.

We are though talking about timeframes beyond the reliable.

In the nearer timeframe, December opening on a very typical note, a broadly atlantic driven pattern, bouts of mild wet weather interspersed with cooler drier conditions. For the north half of UK quite cold Tues-Wed with wintry precipitation interest - one to watch. and the promise of perhaps quite a cold next weekend, again still outside the reliable.

 

[Penrith Snow]

 carinthian Hope your right, I am planning on visiting Grindlewald and the Jungfrau around the 10th to 15th December, leaving the booking of flights etc to the last minute to ensure the weather is clear and cold with snow on the ground.

EC definitely an improvement this morning with cold air sinking deep into Europe, yes with get the limpet UK High but with low heights in the Mediterranean options abound for the high to move north or west.

Could be a lot worse.

Andy

[Mike Poole]

 northwestsnow

+NAO generally up to T168, then this for T192-T240:

The signal is for an Atlantic ridge pushing into Scandi to our north.  Cluster 1 (19) has the strongest block, and also the best placed, bringing in a northeasterly.  Cluster 2 (17) a slightly watered down version of the same thing.  Cluster 3 (15) pattern slightly west and a northerly but not from far north.  Look at the low heights in Europe on all clusters.

T264+:

Cluster 1 (14) moves the high back into the Atlantic and then weakens a little but still cold.  Cluster 2 (11) morphs to an Atlantic ridge into Greenland.  Cluster 3 (10) is excellent, heights to our north between Scandi and Iceland.  Cluster 4 (9) heights rather collapse before resurging in the Atlantic, not bad for the ‘worst’ one.  Cluster 5 (7) pulls back to a strong Atlantic ridge and northerly flow.

I must admit, I wasn’t quite sure about the negativity in here yesterday, but I was out most of the day and assumed I must have missed something.  Signal strengthens for cold possibilities this morning, or - perhaps - given that it is all in week 2 and there is much uncertainty - the more important statement would be that the signal for a raging +NAO has reduced to practically zero on the EPS once more.

[northwestsnow]

@Mike PooleYup ..

Clusters = good to go

Edited November 30, 2024 by northwestsnow

[Lukesluckybunch]

4 minutes ago, northwestsnow said:

Clusters = good to go

Nice one nw,excited for the 6z

[TSNWK]

 Lukesluckybunch yep.. let's have an eye candy run to get us in  good mood and thread flowing

 

Pulls up chair