Model discussion: Hunt for cold - into mid-January

[Don]

1 hour ago, Ali1977 said:

Going Zonal isn’t a bad thing and we should expect temps to rise as we lose the colder nights. We need to get rid of the U.K./Euro HP as with that still in place we have no chance, so a spell of Zonal is a step in the right direction hopefully!! 

No sure about that as the chances are we will go from very dry and not particularly cold to mild and wet away from the Scottish Highlands!

Edited January 20, 2022 by Don

[SqueakheartLW]

I'll take either GEM 00z Control or P4

Get January out of the way since it looks bleak for anything cold then get us off to a decent start to February

Control

1st Feb

2nd Feb

3rd Feb

4th Feb

P4

1st Feb

2nd Feb

3rd Feb

4th Feb

[Ali1977]

1 minute ago, SqueakheartLW said:

I'll take either GEM 00z Control or P4

Get January out of the way since it looks bleak for anything cold then get us off to a decent start to February

Control

1st Feb

2nd Feb

3rd Feb

4th Feb

P4

1st Feb

2nd Feb

3rd Feb

4th Feb

Not a huge area of heights but goes to show that we don’t need great sets ups to produce the goods. -8c uppers throughout most of this run, so conducive of snow in the whole U.K. 

Just one ensemble from one run but a good example of average Synoptics giving nationwide snow 

[minus10]

2 hours ago, Nick F said:

Perhaps briefly in the short-term, but I'd say a Sceuro high is looking the least likely option in the medium to extended range of the models at the moment.

There are signs of a pattern change upstream over N America in ensemble means, with the current trough over the east moving back to the west and ridging developing over eastern N America. This pulls the ridge over NW Europe west over the Atlantic towards the end of the month into early Feb - allowing more of a westerly to northwesterly trajectory of the upper flow from Greenland / NE Canada into northern/northeastern Europe. So, with time, turning more unsettled and mobile in the north and perhaps eventually in the south at times. With chances of Pm air across the north increasing, could bring some much needed snow for the Scottish ski industry, but for the rest of us, any sign of snow way off!

Oh dear Nick....not what we want to hear if you want cold . A slow change towards milder cloudy with drizzle...yuck ...in the south anyway. I'd be happy just to continue with these sunny days and frosty nights if nothing more wintery is signalled. At least the brighter days help get us through what i say is always the worst month of the year . What with all the depressing news i have always looked apon the weather as being something of a nice diversion...but with this chart..

Not so sure now....

 

[Penrith Snow]

2 minutes ago, minus10 said:

Oh dear Nick....not what we want to hear if you want cold . A slow change towards milder cloudy with drizzle...yuck ...in the south anyway. I'd be happy just to continue with these sunny days and frosty nights if nothing more wintery is signalled. At least the brighter days help get us through what i say is always the worst month of the year . What with all the depressing news i have always looked apon the weather as being something of a nice diversion...but with this chart..

Not so sure now....

 

If anyone can find a worse winter chart I would love to see it!

Apparently snow fell in the central Sahara yesterday for the first time in 40 years, combined with the Greek freeze the message seems to  be if you want snow go south!

Andy

[North-Easterly Blast]

33 minutes ago, SqueakheartLW said:

I'll take either GEM 00z Control or P4

Get January out of the way since it looks bleak for anything cold then get us off to a decent start to February

Control

1st Feb

2nd Feb

3rd Feb

4th Feb

P4

1st Feb

2nd Feb

3rd Feb

4th Feb

As I have said before, the truth is that this winter has not felt all that mild apart from a five day very mild spell over New Year.  The HLB that failed to deliver a cold spell around Xmas, and this mid-late January HP not setting up in a favourable position to get the UK properly cold, and the short lived colder toppler early this month, is all just this winter's main story of the pattern never favourably coming together to get the UK into a proper cold spell.  It seems like all this is what has gone wrong this winter rather than a persistent Bartlett or TM mild zonal train.

[Ali1977]

Well this is different by day 8, compared to the last run

 

Is that a proper PM shot incoming , albeit short lived 

Edited January 20, 2022 by Ali1977

[Ali1977]

Well it’s a short lived cold shot at day 8/9, plenty snow in mid/north Scotland but it looks like reverting to the bore fest beyond that!! 

Edited January 20, 2022 by Ali1977

[Battleground Snow]

18 minutes ago, Ali1977 said:

Well it’s a short lived cold shot at day 8/9, plenty snow in Scotland but it looks like reverting to the bore fest beyond that!! 

Keep the posts coming @Ali1977

Just starting to see signs that the positive AO may end after 10 - 12 days,

high pressure starting to establish in Urals/eastern hemisphere, this may help push the strat vortex about too, ideally want it pushing more over the pole.

 

[damianslaw]

42 minutes ago, Ali1977 said:

Well it’s a short lived cold shot at day 8/9, plenty snow in mid/north Scotland but it looks like reverting to the bore fest beyond that!! 

Just getting a sense all that bottled up cold over the arctic is itching to ease it's way south... it will do but possibly in bursts only.. more northerly topplers..

[PiscesStar]

2 hours ago, SqueakheartLW said:

I'll take either GEM 00z Control or P4

Get January out of the way since it looks bleak for anything cold then get us off to a decent start to February

Control

1st Feb

2nd Feb

3rd Feb

4th Feb

P4

1st Feb

2nd Feb

3rd Feb

4th Feb

Oh dear but yes we've been looking at. Charts for the following month that looked like above all winter and they haven't made it into the reliable.... We can hope that we strike LUCKY in subsequent GFS runs... 

[Cold Winter Night]

The 0z EPS is the poorest EPS ensemble set this winter in my opinion.

Up to day 10, there is retrogression of the High at mid latitudes, and a large chunk of tPV starts moving East again, because of height rises in the NE of America.
Those height rises are too far West for us though, pulling the Atlantic High West as well, and setting up that NW-SE flow over the Atlantic. That does not help our chances of Atlantic/Greenland amplification, let alone the chance of Scandinavian height rises.

In the extended, we see that cool zonal picture broadly supported. Thanks to the trough extending into eastern Europe it's not of the feared Bartlett type, so it won't be very mild, but from there it's a long way to a colder pattern.

[mushymanrob]

Regarding SSWs in February...

Since SSWs started being recorded in 1958, i make it that there were 13 SSWs in February, 3 of which failed to produce a snow event. Apart from the infamous BFTE in 2018, snow events were short lived, pretty localised so not Countrywide, but could be quite sepectacular - like in March 1970 when there was a proper dumping across a wide area.
Snow events following a SSW in February can hit from late February, depending upon when the SSW occurred, into the first half of April.

We can get snow events in March and April without a SSW, but it appears that they are weaker.

Currently there is no SSW forecast and one in early February is unlikely, but SSWs in late February can lead to short lived snow events and a SSW in late February is imho possible, but unlikely.

Oh, i put this here as opposed to the strat threat because i thought it was more apt - hunting for cold.

 

Edited January 20, 2022 by mushymanrob

[snowray]

Just got me thinking, so how about the infamous winters of 1947 and 1963: Was there an SSW that contributed to these particularly harsh winter events? And then there’s the Winters of 1985-1987 that also had some very cold and snowy weather for much of the UK and in Western Europe. We know that there are other factors at play but can we get a longer period of cold and snow without there being an SSW, it just seems to me that these days a SSW is the make or break factor in Winter forecasting.

 

 

[johncam]

2 hours ago, damianslaw said:

Just getting a sense all that bottled up cold over the arctic is itching to ease it's way south... it will do but possibly in bursts only.. more northerly topplers..

If you look at GFS temp profile ,we are losing a lot of the really cold air to our north and east , even Siberia temps are above normal , all the really cold air in Canada and Alaska and their sector of the Arctic 

[TURNED OUT NICE AGAIN]

4 minutes ago, johncam said:

If you look at GFS temp profile ,we are losing a lot of the really cold air to our north and east , even Siberia temps are above normal , all the really cold air in Canada and Alaska and their sector of the Arctic 

It will be just our luck John that when this pattern breaks down all the cold air to the north and east of us will have disappeared.....

[johncam]

2 minutes ago, TURNED OUT NICE AGAIN said:

It will be just our luck John that when this pattern breaks down all the cold air to the north and east of us will have disappeared.....

Yep no doubt that will be our luck , got to hope the models have the pattern change wrong and the high will pull back west rather than south east  

[mushymanrob]

38 minutes ago, snowray said:

Just got me thinking, so how about the infamous winters of 1947 and 1963: Was there an SSW that contributed to these particularly harsh winter events? And then there’s the Winters of 1985-1987 that also had some very cold and snowy weather for much of the UK and in Western Europe. We know that there are other factors at play but can we get a longer period of cold and snow without there being an SSW, it just seems to me that these days a SSW is the make or break factor in Winter forecasting.

 

 

There was no SSW in 62/3, 46/7 there are no records as recording SSWs started in '58.

We can and do get very cold snowy spell without an SSW. They are not the be all and end of, but after 2018's SSW and the mighty BFTE their importance has been heightened. That was an exceptional case.
I think SSWs are only responsible for about 50% of cold snowy spells of varying length.

[Nick F]

46 minutes ago, snowray said:

Just got me thinking, so how about the infamous winters of 1947 and 1963: Was there an SSW that contributed to these particularly harsh winter events? And then there’s the Winters of 1985-1987 that also had some very cold and snowy weather for much of the UK and in Western Europe. We know that there are other factors at play but can we get a longer period of cold and snow without there being an SSW, it just seems to me that these days a SSW is the make or break factor in Winter forecasting.

 

 

Not sure about 1947, don't think records of SSWs go back as far as that, But there were no events between 1960 and 1965. There was a SSW followed by a split on 2 Jan 1985, but was very cold and snowy right from the beginning of the month anyway. The next SSW - which then resulted in a split on 23 Jan 87 followed the infamous extreme cold and snow easterly that month. So both Scandi high blocking patterns in Jan 85 and 87 probably helped trigger the SSW rather than was caused by it. There was a SSW and split in early Feb 1991 - which may have led to the Feb 1991 cold and snowy easterly. Cold Decembers of 1978, 1981, 1995 and 2010 there were no SSWs in the run up, too early for a SSW anyway.

So goes to show, we haven't in the past needed a SSW to bring prolonged cold and snowy spells in the UK. But, with global warming, it seems the Scandi or Greenland blocking highs don't hang around long enough or are becoming more infrequent due to the jet stream being forced too far north or the Polar Vortex becoming too strong each winter, even winters with eQBO and low solar where analogues traditionally showed northern blocking, but now these analogues appear to becoming irrelevant for Europe/N Atlantic. So we are more reliant than ever on an SSW to bring deep cold and snowy patterns. E.g. BFTE late Feb / early March 2018.

But I think there's still potential, for an entirely trop led evolution without SSW to bring Scandi or Greenland blocking, albeit not as prolonged as they used to.

Edited January 20, 2022 by Nick F

[damianslaw]

4 minutes ago, Nick F said:

Not sure about 1947, don't think records of SSWs go back as far as that, But there were no events between 1960 and 1965. There was a SSW followed by a split on 2 Jan 1985, but was very cold and snowy right from the beginning of the month anyway. The next SSW - which then resulted in a split on 23 Jan 87 followed the infamous extreme cold and snow easterly that month. So both Scandi high blocking patterns in Jan 85 and 87 probably helped trigger the SSW rather than was caused by it. There was a SSW and split in early Feb 1991 - which may have led to the Feb 1991 cold and snowy easterly. Cold Decembers of 1978, 1981, 1995 and 2010 there were no SSWs in the run up, too early for a SSW anyway.

So goes to show, we haven't in the past needed a SSW to bring prolonged cold and snowy spells in the UK. But, with global warming, it seems the Scandi or Greenland blocking highs don't hang around long enough or are becoming more infrequent due to the jet stream being forced too far north or the Polar Vortex becoming too strong each winter, even winters with eQBO and low solar where analogues traditionally showed northern blocking, but now these analogues appear to becoming irrelevant for Europe/N Atlantic. So we are more reliant than ever on an SSW to bring deep cold and snowy patterns. E.g. BFTE late Feb / early March 2018.

But I think there's still potential, for an entirely trop led evolution without SSW to bring Scandi or Greenland blocking, albeit not as prolonged as they used to.

Dec 2009 also after no SSW. What has been notable since 2010 is the fact all cold wintry spells have come after a SSW.. Jan 13 and late Feb 18 early Mar 18 only examples.. the cold spring of 21 also probably attributed to the SSW in January.

[Cold Winter Night]

8 minutes ago, mushymanrob said:

There was no SSW in 62/3, 46/7 there are no records as recording SSWs started in '58.

5 minutes ago, Nick F said:

Not sure about 1947, don't think records of SSWs go back as far as that, But there were no events between 1960 and 1965.

??
There was an SSW in 1962/1963, on January 28. That was after roughly 2/3 of the cold already happened though.

Also, November 1962 saw a Canadian warming event, which may have helped in the early onset of that winter.

 

NOAA CSL: Chemistry & Climate Processes: SSWC

CSL.NOAA.GOV

---

NOAA CSL: Advancing scientific understanding of the chemical and physical processes that affect Earth's atmospheric composition and climate.

[Nick F]

13 minutes ago, Cold Winter Night said:

??
There was an SSW in 1962/1963, on January 28. That was after roughly 2/3 of the cold already happened though.

Also, November 1962 saw a Canadian warming event, which may have helped in the early onset of that winter.

 

NOAA CSL: Chemistry & Climate Processes: SSWC

CSL.NOAA.GOV

---

NOAA CSL: Advancing scientific understanding of the chemical and physical processes that affect Earth's atmospheric composition and climate.

Oh ok, depends which reanalysis is used. The NCEP-NCAR showed no SSW between 1960-65, but the ERA40 did detect one. But besides, the SSW was probably triggered by the prolonged high lat blocking that winter, rather then trigged it.

[mushymanrob]

58 minutes ago, Nick F said:

Oh ok, depends which reanalysis is used. The NCEP-NCAR showed no SSW between 1960-65, but the ERA40 did detect one. But besides, the SSW was probably triggered by the prolonged high lat blocking that winter, rather then trigged it.

Thats strange, im not sure why one group detected one but another didnt...

[legritter]

1 hour ago, mushymanrob said:

There was no SSW in 62/3, 46/7 there are no records as recording SSWs started in '58.

We can and do get very cold snowy spell without an SSW. They are not the be all and end of, but after 2018's SSW and the mighty BFTE their importance has been heightened. That was an exceptional case.
I think SSWs are only responsible for about 50% of cold snowy spells of varying length.

Hi gang ,i have read somewhere that a SSW OCCURRED in the winter of 62..63 ,it apparently affected the uk in February 63 and as a result extended that winter , but high pressure brought much drier weather and very low temperatures well into Spring. Of course back then technology was less impressive, think i read a paper in the royal  Meteorological magazine, and on this forum its been mentioned .I wonder IF the winters of the little ice ages had extreme SSWs .nice to see a possible route out of this big high Slug , but think its going to be a long slog ,looks like the Atlantic is awakening, and currently the Gfs is churning out ,will tonights Ecm give us a teaser in its later stages ,cheers and yes sausage baps for all posters .

[Blessed Weather]

Relevant to above discussions, this from the American Meteorology Society:

The Mid-Winter 1963 Stratospheric Warming and Circulation Change

Abstract: The stratospheric warming and circulation change of January and February 1963 are discussed by means of constant pressure charts, time sections and cross sections. Rawinsonde data are combined with wind data from the Meteorological Rocket Network. The warming initially appeared at 10 mb over southeastern Canada as the contour field began its evolution from a pattern dominated by a circumpolar vortex to a nearly symmetrical bipolar pattern. The subsequent events, such as the northwestward spread of the warm air and destruction of the wintertime polar cyclone, are found to be strikingly similar to those of the 1957 warming.

Source: https://journals.ametsoc.org/view/journals/apme/3/1/1520-0450_1964_003_0001_tmwswa_2_0_co_2.xml