Model Output Discussion - New Year and Beyond

[Kirkcaldy Weather]

On 01/01/2023 at 07:30, Kirkcaldy Weather said:

Hope you all had a wonderful Christmas and Santa brought exciting gifts to you

"A big pattern happening between Xmas and New year will be a strengthening Pacific Jet (top of image) this will hone in on California with Atmospheric river conditions likely"

We are seeing those Atmospheric river conditions currently impacting California with historic rainfall amounts and significant Sierra snowfall

"White Christmas % will be highest across West and northwest Scotland then moving along the cold front"

We did indeed have a white Christmas in the areas I mentioned as the cold front turned to snow through Christmas Day evening 

I narrowly missed recording a white Christmas here as the dewpoints were just a smidge too high though nearby towns such as St Andrews had falling snow, though there was a wet snow shower here on boxing day.

'And plenty of signs to be expecting of further wintry outbreaks as December heads to the later stages ^ and especially through the first weeks of Jan"

With 528 dam air frequenting the UK we will continue to see those wintry outbreaks

'Progressing MJO movement through phases 4,5,6&7 over that period'

"weeks 1/2 of Jan with further progression of MJO to phases 6&7"

Matching the next 9 days on the GEFS and GEM ens we see the similarities to phase 5 pattern

 

Superb cam of the Atmospheric river absolutely thumping it with snow

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This long duration Atmospheric river setup is becoming a fair bit more extreme than myself and those who foresaw such conditions developing in advance expected. 

Hopefully everyone in the bay area and the sierras are as prepared as possible as you'll very rarely read Forecast wording to this degree

So why are those conditions persisting? If we look again at the jet stream (especially top of image) the Pacific Jet still powered up and quite extraordinarily we can actually link the Jet from the Pacific right across to the UK, therefore it plays somewhat of a part in the weather we see possibly for the next couple of weeks 

I'd like to mention a bit more of how weather patterns are interconnected in some shape or form I've posted about this before but it really is useful to see the wider picture of meteorological developments which I think some members tend to either deny, forget or perhaps lack interest which is fine we all have varying degrees of passion relating to meteorology.

Atmospheric circulation - Understanding Global Change

UGC.BERKELEY.EDU

A nice webpage for those learning and I particularly like the sentence 'the atmosphere is constantly in motion.' 

Again I think this is often forgotten especially those folk adamant to chuck whole months and seasons in the bin without backing such statements with charts or discussing in detail, I think some of it is to try upset those of us that enjoy snowy weather most ,but after seeing it for a number of years on repeat you learn to not let it affect your energy  

Worth mentioning the December stats in a number of countries

One that's went massively under the radar is Iceland very impressive minimum temps recorded there 

Denmark also below average 

Over 14 years since Londons snow event in Feb 2009 we've had a pretty impressive number of cold / snowy related events 

Feb 2009, Winter 2009/2010, November & December 2010, Feb 2012, winter 2012-13,

#1 Beast February 2018, #2 Beast Feb 2021 + December 2022

I vividly remember meteorological agency "experts" in the media before 2009 saying snow would become a thing of the past 🫣

Something of huge importance is that both extremes of climate change are acknowledged and , record minimum temperatures and snow records are happening year on year around the world, amazing Christmas snow statistic with over half of the US snow covered 

Focusing more again on the current conditions, MJO phase 5 setting the scene here's the surface temperatures associated with phase 5 

 higher than average across mainland Europe (which extends NE) and colder than average for Greenland 

Voila...  

 

[northwestsnow]

UKMO 144

Wedge west of Greenland appearing ,if we can just see the systems off the ES slow down perhaps a ridge in the Atlantic would help..

[frosty ground]

A few storm’s looking likely next week 

and another

if the Atlantic slows down the possibility of a northerly toppled is quite high

Edited January 4, 2023 by frosty ground

[northwestsnow]

Just now, frosty ground said:

A few storm’s looking likely next week 

Looks to our SW ,ANOTHER low about to hurtle towards us ..

That's what is stopping the Azores high getting a foothold in the Atlantic..

For all the talk of a sluggish Atlantic .....

[northwestsnow]

Better,perhaps ?

[frosty ground]

3 minutes ago, northwestsnow said:

Looks to our SW ,ANOTHER low about to hurtle towards us ..

That's what is stopping the Azores high getting a foothold in the Atlantic..

For all the talk of a sluggish Atlantic .....

Look at the wave crossing the U.K. quite nasty, the storm out west reduces in intensity fortunately on this run

[Mike Poole]

GFS trying to push up a ridge in the atlantic T210:

Won’t happen quite like this, of course, but it is the sort of thing we need to keep on seeing in this time range.  Vortex lobe moving east of Greenland, too.  

Edited January 4, 2023 by Mike Poole

[Derecho]

1 hour ago, Purga said:

I know things are desperate when the late January 1947 trope is doled out !

Yup we've condemned the second half of winter to also be a write off now, roll on Spring 

[minus10]

2 hours ago, Met4Cast said:

The difference between now & early December is pretty clear looking at the AAM charts.

Far more westerly momentum in the mid latitudes helping to drive this unsettled, Atlantic driven period we're seeing. Thankfully America is rather warm at the moment too & with the current SST's a particular stormy period isn't expected. The Jet stream is chugging along but isn't extremely strong. The downside to this is that rainfall has been quite slow moving bringing flooding across some parts, I fear that could only get worse in the next week or two. 

The anticipated change to settled weather in week 2 of January appears to have been pushed back beyond mid month now. I had hoped we would see the MJO providing enough forcing to push up a ridge across the mid lats/UK but that doesn't appear to have been the case. 

In terms of cold weather - Meh. Nothing within the next 2 weeks, I do still expect a change to more settled conditions in the 2nd half of this month but with a weak MJO & no SSW, I'm struggling to see where any cold conductive patterns are going to arise from. 

Sorry but bit confused looking at this chart. Does the orange areas refer to increased AAM?..if so i thought that increased AAM was conducive to increased blocking and potential cold, however your stating it represents increased westerly momentum?.Also the graph going into negative territory coincides with the December cold we had...negative AAM?.....apologies but AAM is one of those areas i struggle with...thanks.

[supernova]

Inconsistency run-to-run makes it hard for me to have even the slightest confidence in any of the output currently (longer range stuff in particular) so a good time to seek out trend-spotting posts from some of our more experienced members such as @Kirkcaldy Weather's insightful note above or the sort of stuff @bluearmy@nick sussex@johnholmes (amongst others) are always so good at sharing. Mid month and beyond still my main focus of interest especially if we keep seeing a potential Strat warming (tho nothing currently to suggest a full SSW) such as on this evening's GFS. Slim pickings for sure but not unfamiliar territory over recent years...

 

[Frostbite1980]

4 minutes ago, supernova said:

Inconsistency run-to-run makes it hard for me to have even the slightest confidence in any of the output currently (longer range stuff in particular) so a good time to seek out trend-spotting posts from some of our more experienced members such as @Kirkcaldy Weather's insightful note above or the sort of stuff @bluearmy@nick sussex@johnholmes (amongst others) are always so good at sharing. Mid month and beyond still my main focus of interest especially if we keep seeing a potential Strat warming (tho nothing currently to suggest a full SSW) such as on this evening's GFS. Slim pickings for sure but not unfamiliar territory over recent years...

 

First signs, moving into Feb.........2018 anyone?

[fromey]

3 minutes ago, Frostbite1980 said:

First signs, moving into Feb.........2018 anyone?

How accurate Is this? It is the cfs. Just curious not having a dig at you 

[LRD]

7 minutes ago, Frostbite1980 said:

First signs, moving into Feb.........2018 anyone?

Hope not. A cold spring* following a dross winter (if that's how it does, indeed, end up) would be the final insult

 

 

*wouldn't mind a cold March to be fair as long as April and May are glorious and warm

Edited January 4, 2023 by LRD

[Frostbite1980]

20 minutes ago, fromey said:

How accurate Is this? It is the cfs. Just curious not having a dig at you 

To be fair it is like all models it can flip flop a bit, however I tend to watch the GFS (green lines) and the bias corrected runs as they are closer to the mark but even two of those just about reverse the winds. Its more looking at trends moving forward for me to see if the trend continues or indeed increases the chances but this is the first time I have seen 2 bias corrected runs reverse the winds at 10hpa.

[Rain All Night]

30 minutes ago, fromey said:

How accurate Is this? It is the cfs. Just curious not having a dig at you 

Not the question you asked, but I have always wondered how the CFS compares to the GFS when looking at the Z500+MSLP charts within the 0-7 day timeframe.

[Ali1977]

Day 12 - MJO push maybe. And yes, I know they are v v unlikely - just highlighting an increase in blocked charts again - not day 16 either!! 

[Rain All Night]

3 minutes ago, Ali1977 said:

Day 12 - MJO push maybe. And yes, I know they are v v unlikely - just highlighting an increase in blocked charts again - not day 16 either!! 

I'd take an anniversary redux next week:

A lot more vortex going on to our north a year ago!

[Rain All Night]

6 minutes ago, RainAllNight said:

I'd take an anniversary redux next week:

A lot more vortex going on to our north a year ago!

It's very interesting for me as a newbie to see how pathetic the tropospheric vortex is this year, and yet we still get weeks of unsettled weather!

[northwestsnow]

It's just low after low after low.

I hate the Atlantic.

[Mike Poole]

38 minutes ago, RainAllNight said:

It's very interesting for me as a newbie to see how pathetic the tropospheric vortex is this year, and yet we still get weeks of unsettled weather!

Yes, amuses me when I see people referring to default Atlantic, and raging vortex etc.  The setup is unusual, and it is frustrating that that in and of itself doesn’t equal cold for the UK.  But it doesn’t.  ECM T240, and signs of a little more upstream amplification in the models in general, but I expect the next low (circled red) has to go through as well before we get anything interesting:

[mountain shadow]

4 minutes ago, northwestsnow said:

It's just low after low after low.

I hate the Atlantic.

Would be a huge +NAO if that chart is anywhere close to being accurate. 

We would be weeks away from a cold spell.

[Purga]

Oh well - at least Svalbard is due for an awesome blizzard! Lucky s*ds

[Bricriu]

3 minutes ago, northwestsnow said:

It's just low after low after low.

I hate the Atlantic.

It

 

Just now, Mike Poole said:

Yes, amuses me when I see people referring to default Atlantic, and raging vortex etc.  The setup is unusual, and it is frustrating that that in and of itself doesn’t equal cold for the UK.  But it doesn’t.  ECM T240, and signs of a little more upstream amplification in the models in general, but I expect the next low (circled red) has to go through as well before we get anything interesting:

Another low would most likely come along . The thing is we don't need a raging Atlantic for unsettled weather. It's hard to see how we could go cold from there. 

[Skullzrulerz]

24 minutes ago, northwestsnow said:

It's just low after low after low.

I hate the Atlantic.

Well if we can't get any cold at least we can get some stormy weather at least!

[SqueakheartLW]

Vortex getting hammered at 1hpa

Almost gets a reversal at that level but in the 2021 warming event it went down to -50m/s so still no where near SSW levels based on that but at least it will take the sting out of the vortex and may push it below average.