Model Output Discussion - Into Winter

[LetItSnow!]

Just now, northwestsnow said:

Day 8 and the Siberian express is knocking on Polands door..

Stunning depth of cold across the east. Haven't seen anything like that for a long time, if ever. Stark differences for them compared to (comparitively) warm winter spells they've had in recent years. As long as that is perpetuated then we have increased chances of tapping into it. Very exciting times and a treat considering how awesome it was watching the models this time last year. Just hope it doesn't fall apart like last year!

[Blessed Weather]

ICON 12z very interesting. Big low unable to make progress against an emerging Scandi High:

[MATTWOLVES 3]

Hey Atlantic you've got your work cut out in the days ahead.

Thinks its easy to just barrel through do ya?

Well take a look at that dense cold pool building towards the NE and East! If I were you I'd bugger of South,unless your ready for a real dirty fight. Cause cold air is dense...its entrenched...and its gonna get bloody if you don't back off my son.

There's my less than scientific look on things folks

[That ECM]

1 minute ago, Blessed Weather said:

ICON 12z very interesting. Big low unable to make progress against an emerging Scandi High:

That theme has been growing. 

[northwestsnow]

GFS slightly further south with the low at T24hrs ..

Edit 18 hrs lol

Edited December 1, 2023 by northwestsnow

[ICE COLD]

Well if the ECM goes the icon route tonight up to T192 this place will go crazy (me included) . Lovely icon 

[Rain All Night]

5 minutes ago, Gowon said:

That 250mph low pressure system holding 100 billion trillion tons of water just got brushed aside 

Not before dumping a few of those trillions over my back yard though 

[Lukesluckybunch]

2 minutes ago, ICE COLD said:

Well if the ECM goes the icon route tonight up to T192 this place will go crazy (me included) . Lovely icon 

It would have been great to see a 240 chart there from the ICON!

[Gowon]

1 minute ago, RainAllNight said:

Not before dumping a few of those trillions over my back yard though 

Take it for the team 

[LetItSnow!]

2 minutes ago, Blessed Weather said:

ICON 12z very interesting. Big low unable to make progress against an emerging Scandi High:

This is going to be very tricky and I anticipate bitten off fingers by the time we get to this time next weekend. I think I saw that SST to our southwest are much warmer than normal, so lows blowing up in that region may not be that unrealistic, but coming into a mean block like that, they may very well be stopped in their tracks. With the USA's cold pool being depleted, it seems to me that despite potential short-lived intensity, lows may not have much forcing, and if we do see a major block, it could lead to some rather explosive battleground situations, perhaps with the block more likely to win out compared to usual. That could be the ingredients for some tasty/nasty (depends on your affliction) conditions. Gale-force, bitterly cold southeasterly winds with moisture-laden air can be the ingredients for blizzards.

[Lukesluckybunch]

3 minutes ago, ICE COLD said:

Well if the ECM goes the icon route tonight up to T192 this place will go crazy (me included) . Lovely icon 

The centre of the high being further southwest also..sorry I'm being picky now haha

[Gregulator]

Exeter update ties in with what we are seeing.......in a cautious way of course.

 

[steveinsussex]

2 hours ago, Biggin said:

We had light snow here for a short while and zero rain

He was talking about Sunday 

[WYorksWeather]

I've noticed a lot of disagreement on here between those posters who are tending to follow background drivers and teleconnections, and those who are following the NWP output. I sometimes dabble a bit in both, so don't really take a side on the issue.

Really though, the disconnect isn't as big as a lot of people think it is. Background drivers tend to cause shifts in either probability or impact of weather regimes, whereas NWP gives us a short range look at what is happening.

We can tot up the factors that we know affect our weather, and come to a lot of statements about probabilities and impacts. For example, northern blocking increases the probability of blocking the Atlantic off and getting us into a northerly or easterly, and colder than average conditions over Scandinavia increases the impact (cold) effect of that event if it happens. Similarly, the general trend towards an expansion of the Azores high over recent decades increases the probability of south-westerlies, and the current warm sea surface temperatures increase the impact (mild). Certain MJO cycles favour colder weather, and others favour mild.

But these are only probabilities - we could have a good-looking cold setup with blocking but if the positioning and timing isn't right, we can end up with raging south-westerlies anyway. An SSW can still be a bust. Similarly, despite the record global warmth at the moment, who is to say that Europe can't be the exception to the rule?

In short, the two schools of thought should complement one another. The background drivers give an idea of probabilities and impacts, but aren't a guarantee, and should be looked at alongside NWP, and vice versa.

[Snowy L]

After seeing the huge BFTE being blown away with ease by a small low  in 2018 I've never believed the cold is hard to shift myth, that was a rude awakening. With this cold spell though I do think there could be surprises, because we have positive reinforcements e.g. Canadian warming after the jet fires up, as opposed to waiting the inevitable after our initial block loses strength. If those reinforcements can affect the jet on time there's no reason we can't stay in the cold side. As said a few days ago the timing of those conflicting interactions will result in the messiest charts ever.

Edited December 1, 2023 by Snowy L

[Aiden2012]

14 minutes ago, Gowon said:

That 250mph low pressure system holding 100 billion trillion tons of water just got brushed aside 

Brutal

[Chasbrown]

16 minutes ago, Blessed Weather said:

ICON 12z very interesting. Big low unable to make progress against an emerging Scandi High:

What about the low following it?

[That ECM]

3 minutes ago, Chasbrown said:

What about the low following it?

Answered your own question hopefully. Following it.What we do know from painful past experiences is that if the output heads the way many would like it is NEVER in the bag until “you can see the train coming” they’ve gone wrong at T72 before.

We are in the game, can’t ask for much more at this time.

Edited December 1, 2023 by That ECM

[MattStoke]

GFS marginal AF here on Sunday and Monday.

[Gowon]

2 minutes ago, Aiden2012 said:

Brutal

I hope Kasim can take a joke

[TauntonRoss]

1 minute ago, MattStoke said:

GFS marginal AF here on Sunday and Monday.

Low is too far North, I'll almost guarantee you it's further South, GFS always blows Lows out of proportion 

[booferking]

2 minutes ago, Chasbrown said:

What about the low following it?

I get my magic stick and kaboom that sucker.

[northwestsnow]

Hoping UKMO is a tad further south than Gfs ..

 

[bluearmy]

8 minutes ago, Chasbrown said:

What about the low following it?

If the block is going to hold then big may not be an issue as it will drive stronger WAA and support the ridge even more 

[That ECM]

1 minute ago, northwestsnow said:

Hoping UKMO is a tad further south than Gfs ..