Model discussion: Hunt for cold - into mid-January

[Downburst]

The odd thing about January to me is even though its 31 days like most months it seems to go on and on. It's still a full two weeks before end of month. Normally that would mean we wouldn't really have  a clue what the weather would be like at the end of the month, but this year there is a  lack of momentum in the global circulation means we have a pretty good idea, but there are changes

Most recent EC 46 day shows the 500 hPa  High anomaly move west and lower pressure in the southern continent for first week of Feb

the previous run on Monday didn't show that low in the south

So there is a good chance first week of February will be a noticeable change with more wintriness in the north at least as its very possible to see a trough to our west and norther west digging in, and of course this could amplify between now and then to return to a normal period of mid winter at least. 

[SLEETY]

2 hours ago, carinthian said:

Yes, Sleety woeful regarding prospects of snow but I think it would be rather nice down on the Sussex coast with winter sunshine and some frost at night in the mix. I suppose better than a howling SWly with sludge conditions !

C

Oh its nice ,but you know come spring it will be cold and wet,and the patttern will reseting itself to HLB   once Winter ends ,hopefully its in early spring again,so we see some snow.

Nothing in the ouputs suggests snow out to at least end of January.and if February is going to deliver Snow then you will need to see some signs of it in the ouput after this week has gone.

[mb018538]

Still no real prospect of any rain for a large swathe of the country in the upcoming 10 days. A very long stretch of continuous high pressure for January.

[SqueakheartLW]

Looks like both GEM 00z and GFS 00z are trade offs of sorts.

The options seem to be:

1. Go for the coldest uppers for the 20th January and pay the price later with no cold from 26th onwards and the most likely scenario is milder than average to see out the month if using the 850hpa temps alone as a guide.
2. Sacrifice by going for the least cold uppers for the 20th January and hope this gamble pays back later on with colder uppers and colder conditions to see out the month
3. Pick out the best member for later in the month and take pot luck on what that means for the 20th.

GEM 00z

Using the above options I have managed to narrow down 3 members from the GEM 00z that roughly fit these rules

1. P01 - Coldest uppers for 20th at -11.6C but unfortunately mild for the rest of the run
2. P15 - Least cold uppers for 20th at -5.3C. Pot luck with this one is generally close to average uppers for rest of run.
3. P05 - Coldest uppers on average from 24th January onwards. Got quite lucky with the 20th here with 2nd coldest option on uppers at -11.2C.

I won't show you options 1 or 2 as we don't want to see a mild bore fest with option 1 (P01) or something mediocre and close to average with option 2 (P15)

GEM 00z P05

Here I present you P05 and have picked out the 20th here as well as the coldest points from the period 24th January onwards

20th Jan 06:00     850hpa temp -11.2C

24th Jan 18:00     850hpa temp -8.7C

27th Jan 12:00     850hpa temp -5.8C

29th Jan 12:00     850hpa temp -11.4C

30th Jan 18:00     850hpa temp -10.4C

1st Feb 12:00     850hpa temp -8.7C

GFS 00z

As for GFS 00z I have still managed to get 3 members to fit the 3 options I mentioned back at the top of the post.

1. P26 - Coldest uppers for 20th at -13.6C but unfortunately average or mild for the rest of the run
2. P06 - Least cold uppers for 20th at -6.7C. Pot luck with this one is decent with generally cold condition from the 26th January onwards to the end of the run.
3. P11 - Coldest uppers on average from 24th January onwards. Got quite lucky with the 20th here with cold uppers of -10.3C and then generally cold but not excessively so from around the 24th.

GFS 00z P11

Jan 20th 06:00     850hpa temp -10.3C

Jan 25th 00:00     850hpa temp -7.5C

Jan 28th 00:00     850hpa temp -9.5C

Feb 1st 18:00     850hpa temp -11.2C

[Gowon]

The 6h is teasing us again

[Battleground Snow]

5 minutes ago, D.V.R said:

The 6h is teasing us again

Good old GFS, everything is pointing to a flatter Atlantic, and it throws out a run with euro troughing and high building into Scandinavia

[Nick F]

2 minutes ago, D.V.R said:

The 6h is teasing us again

Yes, we keep seeing these teases from the GFS op, another northerly next Monday, but this time high pressure ridging further NE towards Svalbard in its wake, plus Ural ridge gains strength further east and could play its part later on if its evolution could be believed. But until EC / EPS shows signs of a similar evolution, I remain unconvinced of GFS op carrots at the end of the stick.

EC keen on extending our now familiar mid-lat high nearby deep into eastern Europe while GFS goes for troughing persisting over eastern Europe, big old differences there. Plus there's the ominous deep low heights / trop PV over Greenland and NE Canada on both EC and GFS more than ready to flatten out the flow and make amplification of ridges difficult.

 

[Gowon]

5 minutes ago, Nick F said:

Yes, we keep seeing these teases from the GFS op, another northerly next Monday, but this time high pressure ridging further NE towards Svalbard in its wake, plus Ural ridge gains strength further east and could play its part later on if its evolution could be believed. But until EC / EPS shows signs of a similar evolution, I remain unconvinced of GFS op carrots at the end of the stick.

EC keen on extending our now familiar mid-lat high nearby deep into eastern Europe while GFS goes for troughing persisting over eastern Europe, big old differences there. Plus there's the ominous deep low heights / trop PV over Greenland and NE Canada on both EC and GFS more than ready to flatten out the flow and make amplification of ridges difficult.

 

Tbf to the GFS it has some support from the ICON 0h 

[Updated_Weather]

I mean.. Not saying its right or anything, but GFS has been quite consistent with itself recently.. Whether that is wrong.. Remains to be seen just yet.

Quite interesting imo

[IDO]

This has been represented in the GEFS with a small cluster for a few days and is a variation on the theme of UK HP but favouring us with some colder air to make it a bit more seasonal, temp-wise. Not much of a boom for snow lovers but still we would like to see this one verify if it is the best of a bad bunch. 

The modelling of the tPV in FI is what will determine the ebb and flow of the highs in what remains a NH dominated by the lack of any forcing from the usual suspects. Looking at the 0z -v- 06z, the tPV showing very different profiles, hence the uncertainty regarding the UK high placement and the surface conditions:

0z>  06z>

[minus10]

Yes that signal for linking with ne heights is still being shown on (some) gfs runs...

 

[ANYWEATHER]

Looks like same old same old from the models and perhaps January is going out like a Lamb , but historically speaking late Winter and early spring have a marked increase in Easterly or Northeasterly winds courtesy of a Scandinavian high, so it looks like two setups, going forward into late month into February and this is nothing from what I see from computer models ,just my old seaweed and some years of past experience!  So the lion may well make an earlier appearance than March either the High collapses leaving us with a turbulent Zonal period or the likely candidate is for pressure to build to our North/ North East allowing the coldies some fun. One thing for sure ,we will pay for the benign conditions at present. .....☺

[carinthian]

3 hours ago, carinthian said:

Morning all. Just a bit of a ramp from me. That cold front shown on the fax is now currently producing a fair bit of fresh snowfall and lowering of temps in the Eastern Alps. I know you lot are barren of any snow prospects but a High Centre close to the British Isles produces some really good snowfalls synoptics on its most Eastern  boundary, especially when a localised NEly flow develops in these parts of the Austrian Alps.

This latest run from GFS below just highlights what I observe as regards to above post. Flat calm under high pressure across most of the British Isles, whilst note the pressure gradient across the Eastern Alps. Currently our mountain is storm bound with NE ly gusts of 100km/ph.

C

Edited January 17, 2022 by carinthian

[SqueakheartLW]

Got a nice treat on the GFS extended run today

Feast your eyes upon P8 today

Thu 20th Jan 06:00     850hpa temps -10.7C

Has a decent early snap of cold for the 20th with uppers getting down to a nice -10.7C. A risk of snow showers near to the east coast, otherwise generally dry and cold.

Mon 24th Jan 00:00     850hpa temps +3.2C

That cold snap doesn't last very long and we are soon back under mild uppers although with high pressure very much dominating from the period of the 20th to 24th it may not in fact be that mild at the surface.

Wed 26th Jan 00:00     850hpa temps -11.3C

Our next blast of cold arrives and sends the uppers crashing down to -11.3C. Snow showers become a risk here once more.

Fri 28th Jan 00:00     850hpa temps -2.0C

Another brief less cold spell arrives but with uppers less mild than the first time it should in theory be less mild than before but with lower pressure in charge here it may turn out milder at the surface.

Sat 29th Jan 06:00     850hpa temps -9.4C

We are soon back into colder air again with snow showers becoming a risk once again, this time more in the N and W.

Sat 29th Jan 18:00     850hpa temps -4.1C

A trough is moving down within the flow and despite less cold uppers this is within cold air so could very much be a band of snow pushing southwards through the UK, especially further N and E. S and W parts could see less cold Atlantic air getting in the mix here so rain or sleet more likely here.

Sun 30th Jan 12:00     850hpa temps -9.2C

Once the trough and fronts clear through we are straight back into a cold icy Arctic blast and snow showers become the order of the day once more.

Tue 1st Feb 12:00     850hpa temps -6.3C

We remain in the cold and blocked pattern and by this stage the flow is becoming more and more easterly so this is starting to push the snow showers further inland.

Thu 3rd Feb 00:00     850hpa temps -8.3C

Despite the low pressure the flow has generally slackened off here so even if there may be a snow shower risk still the main focus here will be the cold nights and the hard frosts over existing snow cover.

Fri 4th Feb 12:00     850hpa temps -8.6C

We are soon back into a more general easterly flow once again so the focus switches back more towards the snow shower risk rather than the frosts.

Sun 6th Feb 12:00     850hpa temps -10.5C

The persistence of this easterly flow is now starting to pull colder uppers into the mix so the snow shower threat only increases as we go on with this persistent cold spell.

Tue 8th Feb 12:00     850hpa temps -9.4C

Just when we thought easterlies looked locked in the weather has other ideas and decides it's time for us to be struck with cold from the north now. This reduces the snow shower threat in more western parts but the east remains at risk.

Thu 10th Feb 00:00     850hpa temps -10.7C

We are now starting to bring the coldest uppers so far in this cold spell into the UK and with low pressure close by to eastern parts there is a threat of snow here still. Western parts still likely to be drier closer to that high pressure.

Fri 11th Feb 00:00     850hpa temps -10.6C

Looks like the south are about to get in on the fun and games with snow here as low pressure pushes up from the south and threatens a change to milder conditions and with engaging all that cold UK air there could be persistent snow here. Snow showers likely in other areas, especially further east.

Fri 13th Feb 00:00     850hpa temps -13.2C

We reach the coldest point of this GFS extended P8 run here in terms of 850hpa temps at -13.2C. The attempt by low pressure to the south to end the cold spell has failed totally and anyone hoping for persistent snow away from the south will have been disappointed. However eastern areas are still very much in the snow game and have been doing quite well in this fantasy cold spell.

Sun 15th Feb 00:00     850hpa temps -6.1C

Another brief spell of less cold uppers but with uppers still very much at or below -5C and registering a peak less cold value of -6.1C at Scunthorpe and with another trough moving down from the north this could be the next more widespread persistent snow event, only this time with colder air than the first one in late January then more likely snow everywhere this time around.

Thu 17th Feb 12:00     850hpa temps -7.5C

On and on this cold blocked pattern goes and with a NE flow the snow shower threat resumes once the trough has cleared through. What a fantasy cold spell this is turning out to be.

Sat 19th Feb 00:00     850hpa temps -8.7C

Even though it isn't that visible here another trough is moving through the colder air. This time it is pushing in off the North Sea bringing either a heightened snow shower risk or even another band of persistent snow in from the NE so yet more snow to satisfy the coldies snow fix.

Sun 20th Feb 00:00     850hpa temps -11.1C

We end GFS extended member P8 with ... you guessed it ... a return to an easterly flow with sub -10C uppers making a return to the UK once more and after the band of snow has pushed through we see further snow showers pushing in from the east. Looks to be no imminent sign that this fantasy cold spell is coming to an end anytime soon.

If only P8 could have been an even longer run. I would have liked to see how long this fantasy cold blocked pattern continued on for.

I think this one needs banking so we can hope it turns out to be the trend setter and the run that comes off.

If only

[damianslaw]

Good to know reading for lack of any 'forcing' mechanisms on northern hemisphere pattern for foreseeable. Perhaps the drivers are playing ball but instead of high latt blocking we are seeing mid latt blocking.. what has happened to the Atlantic? All that cold to the NW should be fuelling the jet alas our way alas cant seem to budge the high away. Odd!

[SqueakheartLW]

This is a good one. Today's 0C isotherm chart shows 2000 metres for 0C isotherm yet we've had a frost. Shows the level of the inversion we have right now.

[knocker]

26 minutes ago, SqueakheartLW said:

This is a good one. Today's 0C isotherm chart shows 2000 metres for 0C isotherm yet we've had a frost. Shows the level of the inversion we have right now.

Probably better illustrated by the 0900 Larkhill sounding with the radiation inversion under the subsiding air column of the high pressure. But of course this is not taking into account the Tg temp

Edited January 17, 2022 by knocker

[Downburst]

59 minutes ago, damianslaw said:

Good to know reading for lack of any 'forcing' mechanisms on northern hemisphere pattern for foreseeable. Perhaps the drivers are playing ball but instead of high latt blocking we are seeing mid latt blocking.. what has happened to the Atlantic? All that cold to the NW should be fuelling the jet alas our way alas cant seem to budge the high away. Odd!

I was reading an excellent blog on severweather.eu on the upcoming 2022 view. Well worth a read, particularly for me on the QBO explanation as it really is explained well for anyone who wants to know more, not you damianslaw as of course you understand it. But anyway, great chart showing composite for the 13 largest La Nina since 1950 (~70 years) and we are not a million miles away from that this Dec/Jan. So my guess is the December/January this year are playing out as  La Nina pattern that is forcing itself downstream from North America into our area, playing to script.

[Cold Winter Night]

GFS is remarkably keen on changing the pattern to a setup more favourable for cold in NW-Europe.
There are differences between runs, but we keep seeing that GFS models interactions between a more amplified version of the persistent High near us and the Russian High, resulting in Scandinavian heights.
This GFS6z 300h chart is illustrative of that.

GEFS offers decent support for colder influences, either from something similar to the Operational run, or from a more amplified Atlantic High bringing Northerlies.

Now , is there any sign of support for this in the European ensemble?

First, up to day 8, the regimes chart show that the ensemble doesn't offer us a clear direction at all. Lots of scatter, barely defined regimes. It's all variations on the 'High-theme', either more Atlantic based, or more NW-Europe based.

On to the 192h-240h clusters.

They show continued influence from the High, but there are clusters that are not unlike what GEFS has been showing us so persistently, taking the High further North (cluster 4, 6). The HRES Op is in a smaller cluster, but I would say that cluster looks better than the Op itself.
Also, the return of the entire tPV to Canada doesn't seem to go as smoothly as it seemed before.

The wind direction chart for De Bilt has a decent group of members bringing winds from the NE quadrant, there is some support for the GFS/GEFS solutions.

Into the extended 264h-360h, I would not say it's looking like a coldies' dream, but it doesn't give the zonal picture it had yesterday. Whatever blue border/NAO+ charts are in there are more snap shots in the High moving NW and back SE than a true NAO+ setup.

The large majority still has that High with a tPV pulsating West-East-West, but the possibility of heights ending up in a place more favourable for us is still there.

So, compared to model output over the weekend, the EPS took a modest step towards GEFS. But that doesn't say anything about the next run, unfortunately.

 

[northwestsnow]

3 hours ago, bluearmy said:

The proposed repeated dumbelling displaced Azores high has indeed been edged east by the models (we expected it wouldn’t become a set feature which the nwp seemed keen on ).  So we are left with a nw euro high for a period. At the moment, it looks like the flow is more likely to flatten than amplify further.  whilst the south could remain close enough to a euro high to keep some frost (and possibly fog), the north will likely see a succession of Atlantic systems headed across.  That’s the way the ens are headed and have been for a few runs …..the ec and gem ops keenest whilst the gfs less so. 

It's rapidly turning into a horror show Blue.

That PV is going nowhere lookingat the 00z data 

It's that grim I've been looking at data from the Tonga volcano eruption to assess if the impact will have any effect on the atmosphere!

Edited January 17, 2022 by northwestsnow

[feb1991blizzard]

3 hours ago, bluearmy said:

The proposed repeated dumbelling displaced Azores high has indeed been edged east by the models (we expected it wouldn’t become a set feature which the nwp seemed keen on ).  So we are left with a nw euro high for a period. At the moment, it looks like the flow is more likely to flatten than amplify further.  whilst the south could remain close enough to a euro high to keep some frost (and possibly fog), the north will likely see a succession of Atlantic systems headed across.  That’s the way the ens are headed and have been for a few runs …..the ec and gem ops keenest whilst the gfs less so. 

Even any SSW precursor patterns have disappeared or not strong enough signals from even the GEFS, winter proper (DJF) is now a proper cold spell 1.03 NO - 34 YES, remember quoting similar odds 2011 but that was about Jan 25th. @CreweCold has called this winter spectacularly right.

[Sever siberian icy blast 2]

3 hours ago, Downburst said:

The odd thing about January to me is even though its 31 days like most months it seems to go on and on. It's still a full two weeks before end of month. Normally that would mean we wouldn't really have  a clue what the weather would be like at the end of the month, but this year there is a  lack of momentum in the global circulation means we have a pretty good idea, but there are changes

Most recent EC 46 day shows the 500 hPa  High anomaly move west and lower pressure in the southern continent for first week of Feb

the previous run on Monday didn't show that low in the south

So there is a good chance first week of February will be a noticeable change with more wintriness in the north at least as its very possible to see a trough to our west and norther west digging in, and of course this could amplify between now and then to return to a normal period of mid winter at least. 

Right guys iv had an absolute mare with my old account and email address so iv set up a new account under a new email and added a number at the end so you know who I am

Ps I'm glad to be back its very frustrating not been able to get involved! Thankfully the mods are crap atm! 

Re the above chart, one thing iv noticed recently is the low anomaly in southern Europe, thats never a bad thing and will always be a must if we're to salvage anything in the second half of what so far is very rubbish winter! 

Let's hope the mods improve over the next few days, I enjoy the frost and fog so all not lost... 

See you tonight

Edited January 17, 2022 by Sever siberian icy blast 2

[phil nw.]

Unfortunately there is little cheer from the ensembles at the moment for any sign of real cold and snow,at least as far as they go out.The NH pattern remains quite static with the large Canadian/Greenland vortex segment holding firm and keeping any chance of Atlantic ridging,let along northern blocking,almost nil.

There seems nothing upstream showing up to shake up the cold upper core over NA and it just keeps giving.Ongoing prospects of snow and cold outbreaks for the Winter fans over there,especially on the eastern side.

The ens and clusters show the high still nearby but there does seem to be the trend to flatten the Atlantic jet and place it a little further south by the end of week 2.

                                                               

The westerlies are showing up over more of the country as time goes on.Gefs a little slower to do this but by day 15 that seems to be the favourite outcome currently.

We will continue to see some frosts and crisp sunny days this week and then we will have to see where we go with this high and any sign of the Atlantic moving in over the top as the ens. suggest.

 

[damianslaw]

15 minutes ago, phil nw. said:

Unfortunately there is little cheer from the ensembles at the moment for any sign of real cold and snow,at least as far as they go out.The NH pattern remains quite static with the large Canadian/Greenland vortex segment holding firm and keeping any chance of Atlantic ridging,let along northern blocking,almost nil.

There seems nothing upstream showing up to shake up the cold upper core over NA and it just keeps giving.Ongoing prospects of snow and cold outbreaks for the Winter fans over there,especially on the eastern side.

The ens and clusters show the high still nearby but there does seem to be the trend to flatten the Atlantic jet and place it a little further south by the end of week 2.

                                                               

The westerlies are showing up over more of the country as time goes on.Gefs a little slower to do this but by day 15 that seems to be the favourite outcome currently.

We will continue to see some frosts and crisp sunny days this week and then we will have to see where we go with this high and any sign of the Atlantic moving in over the top as the ens. suggest.

 

One option I've mentioned is for a slow sinking south of the high through end of the month with a westerly flow on its northern flank.. it then retreats SW and further west and we see a more NW-SE alignment of the jet first week Feb which would increase chance of something more wintry. This most likely if we see energy in the PV shift to the NE rather than stay sat to our NW. Either way I'm not really seeing an Atlantic onslaught anytime soon meaning winter 21-22 will be up there with 16-17 as one of the quietest in a long time with little storm activity. We shall see. Must admit for mid winter this is exceptionally benign weather. 

[bluearmy]

Coldies can take some comfort that the  eps clusters are as numerous as they come (indicating a fair degree of uncertainty although that could be timing) and there are some which are still showing some higher height anoms upstream over the Canadian Arctic