Winter 2022-23 : Forecasts and Discussions

[Weather-history]

On 17/12/2022 at 10:47, Summer8906 said:

On the same topic, what about Decembers which were cold early on, becoming much milder later (as this one appears to be doing)?

So a breakdown sometime between mid-month and Christmas, which then persists for at least two weeks.

We haven't had such a year recently, but possible candidates include 1990, 1991, 2002, 2007 and 2012.

Of these it is notable that none of the Februaries following were zonal, though temps were varied. In fact all were generally anticyclonic though only Feb 1991 and 2013 were actually cold. The Januaries were mixed, only 2008 was zonal and wet almost throughout but there was something of a tendency for mild at first, colder later.

If we then extend it to years where the breakdown occurred rather later, towards the end of the year, we could also add in 2003 and 2005. The following Januaries were mild and wet, colder later (2004) and mild first half, colder second half (2006). Both Februaries tended anticyclonic.

I'm not sure how similar the current atmospheric pattern is to 1990, 1991, 2002, 2003, 2005, 2007 and 2012 - but if it is, it might suggest that any zonal spell will peak in January, particularly the first half, leaving more benign conditions (which could be either cold or mild) in late winter.

Going further back, the "sandwich winter" seemed to be a feature of some years of the late 1960s and early 1970s, i.e. cold Dec and Feb, and mild Jan. IIRC from archives, the three winters of 1967/8, 1968/9 and 1969/70 were all like that.

There is of course (as has been said above) the 1981/2 and 2010/11 "frontloaded" type, but neither of course featured a definitive breakdown until into the new year.

December 1920 and December 1925 both had very mild last weeks following a cold spell with the change happened at Christmas. The very mild weather continued right through January 1921 and with January 1926, there was an easterly spell mid month but after that it was very mild more or less until March.

Playing on a hunch, I think we have seen the coldest spell for the 2022-23 season. 

[Don]

Latest Met Office Contingency forecast January - March 2023

https://www.metoffice.gov.uk/binaries/content/assets/metofficegovuk/pdf/business/public-sector/civil-contingency/3moutlook_jfm_v1.pdf

[damianslaw]

52 minutes ago, Don said:

Latest Met Office Contingency forecast January - March 2023

https://www.metoffice.gov.uk/binaries/content/assets/metofficegovuk/pdf/business/public-sector/civil-contingency/3moutlook_jfm_v1.pdf

Suggests may see high pressure at least for a time in January bringing some colder frosty weather, last year we had high pressure in Jan, but centred unfavourably for anything especially cold, this year heights may be slightly further north. 2012-2013 did something akin to this winter so far, a cold first half to Dec, very mild second half and start to Jan then a cold 2 week spell mid Jan, but that thanks to a SSW, not saying this will happen. 2017-18 also similiar to an extent with a shorter lived colder spell mid Jan. That also brought a SSW late on though.

 

[BLAST FROM THE PAST]

Leading on, was happy with the 1st 1/3rd of Dec but Xmas week a rather disappointing scenario and WRONG.  However, Hemispheric events were good with the severe cold pooling in Siberia and the incredible Nor’Easter.  Did the severity of this event have a hemispheric impact that scuppered us over here?  Don’t know but as it locked in the models pulled away from the cold scenario over here and we went ‘Atlantic’.

Now for Jan, I think there’s going to be an incredible vast super cold development during 2nd week/midmonth (equivalent of the Nor’easter?) for Russia/Siberia/Mongolia/China/Korea.  Certainly in the ‘very notable’ category but I think records will be felled. Will it spread west?  I still think a deep LP or 2 between 10-14 Jan on a NW/SE  axis (trough disruption) may be the trigger to set us up to get in on the cold.  Surely this huge cold pool has to have an effect down the line?

 

BFTP

Edited January 2, 2023 by BLAST FROM THE PAST

[Weather-history]

On 19/12/2022 at 06:27, Weather-history said:

December 1920 and December 1925 both had very mild last weeks following a cold spell with the change happened at Christmas. The very mild weather continued right through January 1921 and with January 1926, there was an easterly spell mid month but after that it was very mild more or less until March.

Playing on a hunch, I think we have seen the coldest spell for the 2022-23 season. 

It is looking increasingly  as though this winter is falling into the above categories. I think the first half of January is pretty much a write off for anything of note, wintry wise, now, certainly on the scale of what happened during December. I'm not convinced by the second half of January is going to deliver much. 

I still can't  shake the feeling a notably cold February is around the corner. You can't keep returning above average February one after another. When you think about it, last December had a CET that was 1.2C below the 1961-90 average. So why can't February do it?  The last such February was 1996! There have been 4 Decembers since that February of 1996 that were at least 1.0C below the 1961-1990 average and there hasn't been one February since 1996 going off the updated CET figures. Who knows? 

[Sunny76]

3 hours ago, Weather-history said:

It is looking increasingly  as though this winter is falling into the above categories. I think the first half of January is pretty much a write off for anything of note, wintry wise, now, certainly on the scale of what happened during December. I'm not convinced by the second half of January is going to deliver much. 

I still can't  shake the feeling a notably cold February is around the corner. You can't keep returning above average February one after another. When you think about it, last December had a CET that was 1.2C below the 1961-90 average. So why can't February do it?  The last such February was 1996! There have been 4 Decembers since that February of 1996 that were at least 1.0C below the 1961-1990 average and there hasn't been one February since 1996 going off the updated CET figures. Who knows? 

Anything is possible in a post 1987 climate. 

[mountain shadow]

3 hours ago, Weather-history said:

It is looking increasingly  as though this winter is falling into the above categories. I think the first half of January is pretty much a write off for anything of note, wintry wise, now, certainly on the scale of what happened during December. I'm not convinced by the second half of January is going to deliver much. 

I still can't  shake the feeling a notably cold February is around the corner. You can't keep returning above average February one after another. When you think about it, last December had a CET that was 1.2C below the 1961-90 average. So why can't February do it?  The last such February was 1996! There have been 4 Decembers since that February of 1996 that were at least 1.0C below the 1961-1990 average and there hasn't been one February since 1996 going off the updated CET figures. Who knows? 

Hi Weather, just to confirm. The last below average temperature February was in 1996?

[Weather-history]

49 minutes ago, mountain shadow said:

Hi Weather, just to confirm. The last below average temperature February was in 1996?

The last one was 2018 for the CET, but the last one that was at least 1.0C below the 1961-90 average was 1996 since Hadley updated the CETs. 

 

[mountain shadow]

56 minutes ago, Weather-history said:

The last one was 2018 for the CET, but the last one that was at least 1.0C below the 1961-90 average was 1996 since Hadley updated the CETs. 

 

Thanks. Depressingly sobering.

[damianslaw]

13 hours ago, Weather-history said:

It is looking increasingly  as though this winter is falling into the above categories. I think the first half of January is pretty much a write off for anything of note, wintry wise, now, certainly on the scale of what happened during December. I'm not convinced by the second half of January is going to deliver much. 

I still can't  shake the feeling a notably cold February is around the corner. You can't keep returning above average February one after another. When you think about it, last December had a CET that was 1.2C below the 1961-90 average. So why can't February do it?  The last such February was 1996! There have been 4 Decembers since that February of 1996 that were at least 1.0C below the 1961-1990 average and there hasn't been one February since 1996 going off the updated CET figures. Who knows? 

Yes quite surprising, given February tends to be less atlantic dominated than Dec and Jan and traditionally when higher pressure and its associated frost, and northerlies and easterlies are more likely. We can't have been far off in 2010 and 2013, they were both quite cold wintry months but without and exceptional cold. 2018 came very close, had the cold arrived a bit earlier. 2009, 2012 and 2021 brought very cold first halves cancelled out by very mild second halves. 2005 cold came too late and wasn't especially potent. 2001 and 2006 promised much but failed with cold coming late on and more so in March. 

What about January, can only think 1997, 2010 were at least 1 degree the norm, 2001, 2009, 2011 and 2021 colder than normal but not 1 degree. 

[Jacob Gamer]

It is getting pretty likely for

an SSW 

[BLAST FROM THE PAST]

On 02/01/2023 at 20:38, BLAST FROM THE PAST said:

Leading on, was happy with the 1st 1/3rd of Dec but Xmas week a rather disappointing scenario and WRONG.  However, Hemispheric events were good with the severe cold pooling in Siberia and the incredible Nor’Easter.  Did the severity of this event have a hemispheric impact that scuppered us over here?  Don’t know but as it locked in the models pulled away from the cold scenario over here and we went ‘Atlantic’.

Now for Jan, I think there’s going to be an incredible vast super cold development during 2nd week/midmonth (equivalent of the Nor’easter?) for Russia/Siberia/Mongolia/China/Korea.  Certainly in the ‘very notable’ category but I think records will be felled. Will it spread west?  I still think a deep LP or 2 between 10-14 Jan on a NW/SE  axis (trough disruption) may be the trigger to set us up to get in on the cold.  Surely this huge cold pool has to have an effect down the line?

 

BFTP

Going on from above.  Records have fallen and we’ve seen the coldest Siberian temp for some time.

The trough sinking NW/SE is upon us, (adjusted somewhere to say 10-17).  So where do we go from here?  I think the models have the next 7 days or so right with another ‘milder’ interlude.  But am looking for another trough S/SE plunge to our east with HP moved to our west around 25th.  I am not seeing a Greenland HP but another attempt at HP to our west linking to a Russian / Scandi (South Scandi?) HP.  I still believe that HP to our East is most likely for Feb…but will the flow be E/SE or S due to Atlantic trough pressure? Not convinced on a real cold Feb….maybe 1st week…but lots to hope for as orientation could make a big difference.

 

BFTP

[BLAST FROM THE PAST]

So here we are, HP building and looks like taking a foothold.  Got a feeling that we are more likely to get HP over us then a SE’ly flow, southerly at times. Fine margins between getting cold actually being Springlike.  I’ve gone for a 7c CET…..bit high but my money is on the HP holding in a place over us where we are calm or get a general S to SE flow/feed

 

 

BFTP

Edited February 3, 2023 by BLAST FROM THE PAST