Model output discussion - cold spell approaching?

[V for Very Cold]

Well I’ve tried to read the charts for Thursday.... all I think is whatever falls out of the sky.... there’s going to be an awful lot of it!

[Methuselah]

7 minutes ago, Penrith Snow said:

The advantage of a NAO that is slightly west based is that the Arctic air spends longer over the North Atlantic and approa hes the UK from the West. Ok this lifts the uppers but massively increases the chances of snow a across the bulk of the UK. Surely that's better than a screaming frigid direct northerly where you have to be on the beach at Scarborough to see any snow.

I understand its maybe not the  best situation for the southeast but you are at risk from runners along the troughs bottom.

Prizes for all!

Andy

And a million times better than the grey, dry dross-fest that was February 1986!

[on the coast]

1 minute ago, East_England_Stormchaser91 said:

Absolutely right. Plus we are a small island, where 200 miles of a pattern shift can win or lose you the game! It’s very fine margins. 

How I miss a decent Northerly living in Scarborough.  The outlook looks good long term for us living by the sea with the ECM showing cold showing to build up in stagnant air. As they say get the cold in first.

[sebastiaan1973]

Model charts for England (Temperature) | ECMWF IFS HRES (10 days)

METEOLOGIX.COM

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ECMWF IFS HRES (10 days) - Current forecast valid for 01/12/2021, 10:00pm of parameter "Temperature", model chart for map "England"

For the individual ENS members. And the plume De Bilt.

[Man With Beard]

Looking through the ECM ensembles for snow depths, roughly 40% of members have the UK pretty much covered in snow from top to bottom, perhaps another 40% with snow just mainly northern hills, and the rest somewhere in between. That's actually slightly better than you'd expect from an average northerly.

The positive thing for snow lovers is that it's not just slightly cold, it's also unsettled, and it is also the final third of January, more or less the only period of the year where it isn't too hard to get a snowfall as long as it's not zonal.

[GSP]

35 minutes ago, Timmytour said:

I'm getting the Stellas in ready for the pub run.....

The best one last two nights/mornings has been the 0z.

[Snowjokes92]

A lot of really strange comments on here. Glad I can look at these charts and keep my personal take on the models to myself and not take every run like its nailed to happen. Especially given how up and down the out put is within 72 hours! 

The cold spilling into the atlantic at 168 hours on the ECM, that a lot of people have picked up on,eventually swings the cold uppers to the UK not long after.  Also given that it is FI anyway and by no means massively supported amongst the output its not something we should be overly concerned about yet in my view. 

[IDO]

1 minute ago, V for Very Cold said:

Well I’ve tried to read the charts for Thursday.... all I think is whatever falls out of the sky.... there’s going to be an awful lot of it!

Yes, a stalling front is fantastic if it turns to snow, but for those that get incessant cold rain, not much fun. Total rainfall until the end of Thursday:

 end Sat:

And another wet period Saturday. N Wales getting close to their seasonal Jan average by the weekend!

[Penrith Snow]

1 minute ago, General Cluster said:

And a million times better than the grey, dry dross-fest that was February 1986!

Absolutely! Bitterly cold is often very dry and February 1986 classic example although Feb 56 was very similar.

I lived at 600feet to the South of Birmingham in February 1986 and we had one 4cms snowfall that evaporated slowly over the next week, it was bone chilling cold but the frost was clear as the air was so bone dry, the landscape  was rarely white and from your lounge window it looked like a Bartlett!

Andy

[Mike Poole]

Feel I’ve been swimming against the tide a bit tonight, but hey ho!

The way I see things from the model output only is this.  Starting with the ECM mean at T240:

The yellow arrow is the advection of cold in our direction around the arctic high, the red is the omega block into Greenland, whether it becomes a cut off Greenland high is still up for grabs, the black circle is the problem area.  ECM op at same time:

There is no clean path for the cold to reach us in the black circle, it is messy.  Because there is nothing driving the weather strongly in this region, out of reach of both the arctic high and Greenland ridge which has now gone too far west on this run.  

A look at the spread same time:

There is some uncertainty associated with the black circle region but I would like to see more here.  Plenty of uncertainty to our west and north, this is what we need to see resolved to determine the actual outcome:

All of which leads to temperatures in the black circle region on the mean rather poor and not what might be expected.

But that is what the models are saying, the situation in the strat is still ongoing and there is plenty more uncertainty outside of the ensemble means still in my opinion, so everything is still very much on the table, that’s just my view on what we’ve seen on the 12s.

All the best, Mike.

Edited January 12, 2021 by Mike Poole

[feb1991blizzard]

15 minutes ago, Penrith Snow said:

Absolutely! Bitterly cold is often very dry and February 1986 classic example although Feb 56 was very similar.

I lived at 600feet to the South of Birmingham in February 1986 and we had one 4cms snowfall that evaporated slowly over the next week, it was bone chilling cold but the frost was clear as the air was so bone dry, the landscape  was rarely white and from your lounge window it looked like a Bartlett!

Andy

Are you sure? - could have sworn there was a fall of 8 to 10 inches.

EDIT : my mistake it was late Jan.

Edited January 12, 2021 by feb1991blizzard

[Chesil View]

9 minutes ago, Penrith Snow said:

Absolutely! Bitterly cold is often very dry and February 1986 classic example although Feb 56 was very similar.

I lived at 600feet to the South of Birmingham in February 1986 and we had one 4cms snowfall that evaporated slowly over the next week, it was bone chilling cold but the frost was clear as the air was so bone dry, the landscape  was rarely white and from your lounge window it looked like a Bartlett!

Andy

That's exactly how I remember Feb 86 bitterly cold but totally boring.

A massive waste of a cold spell.

[Downpour]

1 hour ago, Catacol said:

Hmmm. Where to start.

1. Modelled uppers are likely to drop nearer the time, but -8 is cold and for many not marginal. Rubbish? How many recent winters have you followed!

2. We are very definitely seeing the impact of the SSW. Go check the Berlin charts.

3. What changed in terms of the historic January possibility was the vortex did not split. We are now on the cusp of experiencing about the best impact from a displaced pattern that we can get. Vortex is primarily over Asia and not Canada or the Atlantic, and we have enough displacement to allow an arctic high to bed in. Had the vortex split I think we would have had much greater chance of severe and sustained cold, but it survived by a whisker.

 

How deep the cold might be is very hard to say. I agree with others that we are still in a holding pattern. We will get what we will get and I am sure that many will see snow. We have already had more snow in parts than we have had for the majority of recent winters and some on here must have short memories. 

Looking beyond 240h there is considerable uncertainty about the evolution, more so than is often the case. I suspect this is why many of the more knowledgeable on here have gone a bit quiet - hard to make a call when a call looks near impossible to make. Trop forcing coming out of the Pacific is very hard to read and may, or may not, hit 7/8/1. The extent to which the vortex will remain displaced, where it might move from here and the extent of its recovery is wildly difficult to work out. There is even the outside chance of enough trop forcing perhaps to look to split it later - but then again it may ride out and strengthen. The trop precursor pattern has gone for now due to the displacement, but wave breaking remains in NWP output and the potential for a potent such break to kick the vortex again as we move into February could happen.

But confidence in all this is extremely low. I can’t pick a longer term path at the moment, that’s for sure. End of January gets cold - what happens beyond that is wide open. 

 

Will be another cold rain fest for the majority of the UK population as things stand. Not cold enough, again. 850s too warm, again. 

[Stu_London]

Lots of uppers angst again today. 

There are reasons why -8C would be more likely deliver this time, whereas it didn't last time (although uppers in the south east were generally a degree or so below -8C in the last spell in any event)

However until the overall pattern is decided, it isn't really worth sweating over. I think it could be as late as Friday or Saturday until some sort of model consistency is achieved for next week.

 

[BLAST FROM THE PAST]

22 minutes ago, General Cluster said:

And a million times better than the grey, dry dross-fest that was February 1986!

Where was that? Corker of a month in Swansea

 

BFTP

[johnholmes]

Well, NOAA doing its best to cheer up the cold brigade 6-10 and 8-14

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

[Cold Winter Night]

11 minutes ago, Penrith Snow said:

Absolutely! Bitterly cold is often very dry and February 1986 classic example although Feb 56 was very similar.

I lived at 600feet to the South of Birmingham in February 1986 and we had one 4cms snowfall that evaporated slowly over the next week, it was bone chilling cold but the frost was clear as the air was so bone dry, the landscape  was rarely white and from your lounge window it looked like a Bartlett!

Andy

Haha, and I would absolutely love to see February 86 or 56 repeated one day!
I love snow and photography of white landscapes, but I also love that bone chilling cold and skating on 'singing' deep black ice.

Right now the output has the promise of at least some snow for many, so that's good, and for now you won't have to worry about Feb 86 weather just yet! (But who knows in February... ).

This is exactly why everyone should keep in mind that there are a lot of people on here, spread out over many places, with a lot of personal preferences. What is a dream chart to one, is a sub par to another. And next week it'll all be reversed.

 

[feb1991blizzard]

1 minute ago, johnholmes said:

Well, NOAA doing its best to cheer up the cold brigade 6-10 and 8-14

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

Much more defined ridge than yesterday, seems just as volatile as the op runs right now!

[Severe Siberian icy blast]

2 minutes ago, johnholmes said:

Well, NOAA doing its best to cheer up the cold brigade 6-10 and 8-14

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

Thats been a few years since iv saw something like that. 

Upppers may upgrade again. Who knows but id be suprsied if its not cold enough for snow becsuse the thickness levels are good again 

[SqueakheartLW]

What could be better than this regime chart with all those green boxes along the bottom. Basically the dominant regimes are Block, Atlantic Ridge and -NAO

Also if you add up those 3 options and count all of them as potential colder options they dominate right through the 42 day period

+NAO tries to make an appearance and only 3 boxes show this but at quite long range

[johnholmes]

1 minute ago, feb1991blizzard said:

Much more defined ridge than yesterday, seems just as volatile as the op runs right now!

Not volatile at all, very consistent in how it has dealt with the upper pattern over the past 4-5 days.

[feb1991blizzard]

1 minute ago, johnholmes said:

Not volatile at all, very consistent in how it has dealt with the upper pattern over the past 4-5 days.

Yesterday it showed a WNW, now it shows a straight Arctic Northerly.

[Had Worse]

1 minute ago, johnholmes said:

Not volatile at all, very consistent in how it has dealt with the upper pattern over the past 4-5 days.

Thanks John, your the voice of reason. Dont expect too much and what comes will be a bonus.

[johnholmes]

3 minutes ago, feb1991blizzard said:

Yesterday it showed a WNW, now it shows a straight Arctic Northerly.

so what is the point you are making feb?

Edited January 12, 2021 by johnholmes

[That ECM]

14 minutes ago, johnholmes said:

Well, NOAA doing its best to cheer up the cold brigade 6-10 and 8-14

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

Thanks John. So basically that is saying a flow predominately from the north? Just seeing if I did learn from the other day.

Also Mushy and a few others had a fantastic discussion where there was different views and misunderstandings. Through discussion these were clarified and at no point was anyone rude to the other. If people missed it then they should go back and read for two reasons.

1 perhaps an increase knowledge in how to use these charts.

2 how to discuss and clarify things without point scoring or being rude.

It was a great conversation to read and much appreciated.  

 

 

Edited January 12, 2021 by That ECM