Model Output Discussion - Colder but how cold and for how long?

[mountain shadow]

6 minutes ago, TSNWK said:

Where did the shuffling heights go?

According to Matt Hugo, they were shifted due to the Strat Warming!

Yes, that's right. The one thing we look for all Winter has caused a potentially 2 to 3 week snowy cold spell to become a disappointing 36 hour cold and dry borefest.

 

[southbank]

Looking at the 12z / faxes looks like unfortunate timings with the cold front moving south and the Atlantic low moving in keeps the low on a south of the uk track - just bad luck really.

 

off topic - it’s been a fascinating chase - although feels like it’s been going on for weeks but a thank you to all the inputs on both sides of the coin - looks like very much model fatigue setting in and just bad luck the pieces not there to give icing on the cake with a noteworthy snow event.

 

time to take a break and come back for anything in Feb that may be of interest

[E17boy]

14 minutes ago, iowpompeylee said:

The silence says it all…………. The low is dropping south….. all I can hope is for it to clip the Isle of Wight

Yes totally agree alas seen it here too many times sometimes I call this place the Bermuda Triangle cherry charts 10 days away seem to mysteriously disappear 

it is almost likely now that we are staring down the barrel of the Atlantic to make inroads after this week. The models have quite clearly backed away from any decent wonderland pictures us coldies are waiting for. Sometimes I get the feeling that the writing for the rest of this winter is being written on the walls but dare I say. How long this mild train will carry on for is anyone’s guess. Perhaps February May deliver according to what some of the knowledgeable posters have said, however again it’s worth bearing in mind that factors for 15th Jan were favourable yes granted we are going to get a weeks of cold weather but not the date us coldies thought would finally bring the white stuff. 

No matter how favourable outside factors will look I still believe we will never fill the gab between what’s being shown as favourable and what actually happens.  The weather will do what it wants. 

regards 

[Continental Climate]

The models look pretty horrendous atm if you are of the cold persuasion. This chase has been interesting and tiresome at the same time. I personally have learned a lot. A true greenie high was never really apparent in the models. We had a uk high being sucked up to the south of greenie but no further. To be honest we had a ridge at best. A true greenie high has to develop in that area not be dragged there from the uk or azores. That's the main thing I will take from this chase. Also believe nothing that is not within t72 and has full model and ensemble support because this is the uk and if something can go wrong it will. Time for a break I think for a few days. 

Edited January 14 by Continental Climate

[blizzard81]

21 minutes ago, TSNWK said:

Where did the shuffling heights go?

They've shuffled off to their usual location over southern Europe. Trouble is... Once they locate there, no shuffling will be in evidence - they will stick there like glue!

[alexisj9]

17 minutes ago, mountain shadow said:

According to Matt Hugo, they were shifted due to the Strat Warming!

Yes, that's right. The one thing we look for all Winter has caused a potentially 2 to 3 week snowy cold spell to become a disappointing 36 hour cold and dry borefest.

 

I've warned before they don't always lead to cold, and can also spoil what are good synoptics if there before the warming. I n ver even look there, it's a real shame how things seem to be going down.

[Nick123]

For the north the cold spell is just beginning. Maybe be only 3-5 days but there's a chance of snow. Not trying to rub it in but this forum would have you believe there is no cold spell at all which isn't true!

[blizzard81]

Cmon BA. Hurry up..... I'm cooking buffet food and I'm at risk of burning it awaiting your post

[london-snow]

20 minutes ago, Nick123 said:

For the north the cold spell is just beginning. Maybe be only 3-5 days but there's a chance of snow. Not trying to rub it in but this forum would have you believe there is no cold spell at all which isn't true!

Good luck those up north, However let’s be honest it’s a standard winter spell. Even brief 2-3 day toplers can produce the goods for Scotland and Northern Britain. 

[Froze were the Days]

20 minutes ago, alexisj9 said:

I've warned before they don't always lead to cold, and can also spoil what are good synoptics if there before the warming. I n ver even look there, it's a real shame how things seem to be going down.

So that's 2 winters running a SSW has done nothing?...wasn't there a minor one (a displacement) last February and we ended up on the mild side. You really can't win here in the UK.

Somebody posted an anomaly 1970-2022 just before the winter which showed the deficit in the NH in days of falling snow and guess where was the biggest?...yep! NW Europe.

[bluearmy]

7 minutes ago, mountain shadow said:

According to Matt Hugo, they were shifted due to the Strat Warming!

Yes, that's right. The one thing we look for all Winter has caused a potentially 2 to 3 week snowy cold spell to become a disappointing 36 hour cold and dry borefest.

 

I’m not sure its true that the ssw removes the block 

the strat split which allows the mar to extend north means we end up with a Canadian segment and an Asian segment. This is not the ssw.  This is a consequence of a weak spv and recent warming. It’s not a ssw.  Mike has shown that it’s a consequence of the trop pattern reflecting upwards. 
As the two segments begin to rejoin, we see another Asian warming which encourages the pacific ridge to put pressure the spv which is stretching as it comes back together. Whilst it is stretched, it becomes displaced enough to deliver a reversal of 10hpa zonal flow down to 70N.  The Canadian segment is headed back into the Asian master irrelevant of the ssw that occurs around the 18th. It was modelled to happen before we began to see the level of displacement would actually just reverse the flow. 

the movement back across the n Atlantic of the Canadian segment does indeed happen in tandem with the flattening of the trop pattern. we’re assuming that it’s a trop following the strat but like other recent developments, it’s all seems to happen in tandem, top to bottom (or bottom to top). 

tomorrows cross section of the atmosphere shows it reversed all the way through above 70N. The circle is where we have to see blue for a tech ssw reversal. You can see how this is pretty irrelevant. We have reversal - but not quite at a latitude that would likely see the cold  trough get well to our south. This is where the failure to get the blues down to 60N is possibly an issue next week. 

 

Now to Tuesday and you can see we have an ssw. Woopy do! Judge for yourselves the difference between not having the tech ssw and having the tech ssw. 

 

by day and the blues have drained away with a strong flow at 10hpa top to bottom. Obviously that’s not a string flow in the upper strat but it is down at 500hpa 

 

and a few days later we see the reversed flow back again above 75N (ties in with the Arctic high we saw on that run in fi. 

 

id expect the 12z run to be different by this stage as the polar profile is quite different.  it can’t be easy for the nwp to deal with this inconsistent profile of flow throughout the atmosphere. You’d normally expect the upper strat to be quite predictable. 

[BLAST FROM THE PAST]

I’ve got a feeling that a HP for mainly the south and near continent is looking  to set up shop after the weekend….and dig it’s heels in.
 Going to wait until Wednesday and see where we are then….as there can be adjustments …but Kaprun for 20-27 is looking HP dominated with chilly nights but mildish sunny days.  Still there’s a lovely snowbase in place and a Glacier

 

 

BFTP

[bluearmy]

11 minutes ago, blizzard81 said:

Cmon BA. Hurry up..... I'm cooking buffet food and I'm at risk of burning it awaiting your post

Sorry - watching the footy and posting at the same time! 
nothing doing until the back end of jan at the earliest - and that will probably be from a mid lat ridge which could then either drift ne or nw. 

[jonboy]

On 10/01/2024 at 22:47, Scott Ingham said:

It’s a bit off topic but I’ve read some papers and the amounts of atmospheric rivers 2023 going into the start of this year has been unprecedented so I can sort of see what you are saying without having seen any solid solid evidence. It needs studying more I think 

I agree a lot of research ongoing and ultimately it will in my mind show its impact on the NH winter whether its extra snowfall or increased artic ice. Its the added unknown in science terms that will change a good winter period into an exceptional one.

 

[January Snowstorm]

5 minutes ago, bluearmy said:

Sorry - watching the footy and posting at the same time! 
nothing doing until the back end of jan at the earliest - and that will probably be from a mid lat ridge which could then either drift ne or nw. 

Worth bearing in mind that the Strat and it's effects being a relatively new Science certainly haven't helped in predicting the weather. Maybe too much credence is given to it. You can't beat a bit of experience of how our islands behave and react during the Winter months. The Met Office themselves seem to take a lot of notice now of Stratospheric developments too. Has it helped them be more accurate? Certainly not.

[jonboy]

A lot of gnashing of teeth tonight for what has been well advertised by the likes of Tamara and Met4.

Have faith we have a cold dry spell incoming which will be very welcomed by those areas recently flooded. A brief less cold spell we should see the cold reestablish itself. 

[That ECM]

Edited January 14 by That ECM

[TillyS]

2 hours ago, Anthony Burden said:

Afternoon all,great write up from Matt H all models showing this very cold blast with still a possibility of snow in the south that has lingered on and off for a while. Then what looks like a milder spell that may well be short lived,with northern blocking perhaps showing up in the charts not so far away.The impact  of the blocking being assisted by the SSW.

 

The models don’t show evidence at present that the milder ‘spell’ will be short lived. There is no evidence of northern blocking in the three main models. Nor is there evidence at the moment for the so-called SSW having impact on UK weather to the end of their runs.

It will, indeed, be very cold this week.

Then it will be very mild, and not just for a short spell.

At least that’s what the models say, rather than what we may hope for. Cold, sometimes very cold, until Friday, then distinctly mild, wet, windy and Atlantic dominated, with high pressure to the south of the UK.

5 minutes ago, jonboy said:

 

Have faith 

Evidence is more reliable  

[Downburst]

Plenty of evidence for excellent winter weather into and through February. Should be more high pressure than usual, with anomaly for high pushing to our north west. Hopefully cool, frosty and maybe snow later in February. Don’t go looking for nirvana on every op run for your own sanity, totally mad some of the day 10 analysis, but there you go. What’s wrong with a dry February I don’t know.

[Purga]

ECM offering a glimmer of hope for some Southern snow?

Edited January 14 by Purga

[syed2878]

57 minutes ago, Nick123 said:

For the north the cold spell is just beginning. Maybe be only 3-5 days but there's a chance of snow. Not trying to rub it in but this forum would have you believe there is no cold spell at all which isn't true!

 You’re right of course, there is a cold spell for the usual parts of the UK majority no and as for the Telekon connections well less said the better it is models today look horrendous to say the least Atlantic barrelling through cold and dry for majority of us not what we were expecting

[Marting]

16 minutes ago, TillyS said:

 

The models don’t show evidence at present that the milder ‘spell’ will be short lived. There is no evidence of northern blocking in the three main models. Nor is there evidence at the moment for the so-called SSW having impact on UK weather to the end of their runs.

It will, indeed, be very cold this week.

Then it will be very mild, and not just for a short spell.

At least that’s what the models say, rather than what we may hope for. Cold, sometimes very cold, until Friday, then distinctly mild, wet, windy and Atlantic dominated, with high pressure to the south of the UK.

Evidence is more reliable  

Quite a lot of blocking in the Gefs post 300 (FI) hours, worth a look and one to keep an eye on over next few days to see if the firmer pattern develops. Low, mid, uk based and scandi all showing tonight 

[kold weather]

17 minutes ago, jonboy said:

A lot of gnashing of teeth tonight for what has been well advertised by the likes of Tamara and Met4.

Have faith we have a cold dry spell incoming which will be very welcomed by those areas recently flooded. A brief less cold spell we should see the cold reestablish itself. 

I suppose the one upside is the models are at least moving away from a zonal train that was being suggested a few days ago into one more dominated by a HP somewhere over W/C Europe. Should keep the worst of the frontal systems away from a large part of the country.

This week does indeed look very cold, if we can drop away into some very low mins it might be a struggle to get much above 0c again. Its just a bit of a shame that the very cold week is going to be balanced out by perhaps a borderline exceptionally mild spell the following.

[iowpompeylee]

2 minutes ago, Purga said:

ECM offering a limmer of hope for some Southern snow?

I’ve always held the ECM in the very highest regard! this could go until Tuesday morning to nail 

[kold weather]

3 minutes ago, Purga said:

ECM offering a limmer of hope for some Southern snow?

Some for the SW, a coastal kisser for the rest of the south.

I think we are arrowing in now on a close but not quite scenario, albeit one that as mentioned earlier, still needs to be closely watched as all it will take is a minor shift to pull many more into the game again.