Model Output Discussion - New Year and Beyond

[Snowman.]

4 minutes ago, BLAST FROM THE PAST said:

What’s of interest to me is how cold we are, have been with fairly benign set ups…especially to recent years.  It has got really cold, coldest Jan night for donkeys down here from a fairly nothing set up.  And projected, there’s some punchy cold to come from the ‘useless’ northerly topplers.  Not what ‘some’ profess

 

 BFTP

This year has been frost heavy, no snow but definitely cold periods. While CET may say something different, its been some years since we've had dry cold snaps.

[nobble]

10 minutes ago, BLAST FROM THE PAST said:

What’s of interest to me is how cold we are, have been with fairly benign set ups…especially to recent years.  It has got really cold, coldest Jan night for donkeys down here from a fairly nothing set up.  And projected, there’s some punchy cold to come from the ‘useless’ northerly topplers.  Not what ‘some’ profess

 

 BFTP

Hi ,  what do you feel is the reason for the surprising level of cold ??

[Norrance]

Models please guys, 

[Northernlights]

13 minutes ago, BLAST FROM THE PAST said:

What’s of interest to me is how cold we are, have been with fairly benign set ups…especially to recent years.  It has got really cold, coldest Jan night for donkeys down here from a fairly nothing set up.  And projected, there’s some punchy cold to come from the ‘useless’ northerly topplers.  Not what ‘some’ profess

 

 BFTP

Read somewhere that Australia having a cool summer. Aurora Storm and I speculated at Christmas whether the huge amount of water vapour sent into the Southern  Hemisphere atmosphere from  the South Pacific volcano a year ago might have some small effect on world weather patterns. I believe some water vapour was shot 93 miles up escaping into space.

[tight isobar]

Why not  And definitely the road track going forward!.. and this being as some previous suites... And heading into latter frames of sought!.. get once again.... polar- polar continental dripping.. due to mid latitude blocking ( although shallow)- has perfect Synoptics for go placements.... the above notions are slowly becoming more notable... and I’d bet “ confidently “- we’ll get to within +96/+144 hrs... across vast suites!!... the drag n, draw are looking decent... and will likely gain...And perhaps more importantly for most... its great prog/ syncs.. for classic maritime creations = high chance snowfall opportunities... keep watching

Edited January 23, 2023 by tight isobar

[Tim Bland]

Almost a split 

[bluearmy]

4 minutes ago, Tim Bland said:

Almost a split 

But gfs develops it after it’s allowed the Asian vortex to send heavy re Inforcements across to the Canadian side - that lobe is way too strong 

The block and possible splitting needs to be pre day 11/12 to avoid that monster Canadian tpv 

[Vikos]

Are there any charts for the coupling of tpv and spv available?

[tight isobar]

They are getting better via each rolled suite. The p’s- mean- members.. are noting! The London ones!    Be paying a keen look for the ajoining sets for compare @Aberdeen/@ Birmingham ones... as we gain forward

18z

Edited January 23, 2023 by tight isobar

[Ladyofthestorm]

I've never seen such promising charts for winter prospects before this week. The cold from the NW and N is piling up. 

I've never seen such promising charts for winter prospects before this week. The cold from the NW and N is piling up. 

[Derecho]

1 hour ago, nobble said:

Hi ,  what do you feel is the reason for the surprising level of cold ??

It's not surprising I don't think, these winter cold spells have occurred with slack SLP gradients and therefore have allowed for sharp frosts to develop at night. With solar radiation still relatively weak at this time of year, temperatures haven't recovered so much during the day.

In north-western areas there's been more of a gradient with winds off the Atlantic so milder here.

So meteorologically, nothing surprising about it. Uppers can be benign and yet the surface very cold. It's been a while since we have had coldish uppers with very slack surface winds.

Next week looks more typical with polar maritime shots of air interspersed with mild sectors, some coldish uppers but nothing to write home about temperature wise because it'll be windier. Best we can hope for is a few show showers in brief colder interludes or if we get lucky, an area of low pressure coming up against the colder air.

Edited January 24, 2023 by Quicksilver1989

[KTtom]

5 hours ago, Ladyofthestorm said:

I've never seen such promising charts for winter prospects before this week. The cold from the NW and N is piling up. 

I've never seen such promising charts for winter prospects before this week. The cold from the NW and N is piling up. 

Unfortunately I dont think that is a promising sign, well for us anyway, the deep cold is due to the dense PV, this just fires up the jet due to a big temperature gradient. No sign of this cold being released to lower lattitudes at the moment.

[joggs]

7 hours ago, Tim Bland said:

Almost a split 

A vile chart if it's cold you're after.

[KTtom]

21 minutes ago, joggs said:

A vile chart if it's cold you're after.

Yes, it does something similar on the 00z....just look where the PV decides to reinforce...

Edited January 24, 2023 by KTtom

[winterof79]

Interesting UKMO pressure from the pacific and atlantic

 

[Ladyofthestorm]

1 hour ago, KTtom said:

Unfortunately I dont think that is a promising sign, well for us anyway, the deep cold is due to the dense PV, this just fires up the jet due to a big temperature gradient. No sign of this cold being released to lower lattitudes at the moment.

It does but it drags in a constant supply of colder weather behind the cold fronts from the NW.

 

Beast from the East, zonal reversals  are not favourable to areas away from East coasts . Again as already intimated our best shots of cold this winter are the PV stretching as it has done already this winter and sending short shots of freezing snowy air. 

PS NW Scotland has enjoyed some of our snowiest winters in years with no SSW having been body slammed with a potent NLy. 

Look to the NW and N for the PV stretches. Plenty coming.  

[Ladyofthestorm]

1 hour ago, joggs said:

A vile chart if it's cold you're after.

That's the charts that bring non SSW winters of olden times to our shores. 

January 1984!

January 2003 

Someone on the highlights thread  listed non SSW winters. 

Powerful PV like this can produce some very cold spells. 

[IDO]

No real change since I posted last week. Post the HP sinking, after D6, we see the tPV (GEFS mean) relocate to our NW:

So little hope of HL Blocking pre-first-third-Feb. Though, UK on the colder side of the jet, so PM shots from a cold zonal flow; those benefiting from that setup should see some interest. Though caveat, that GFS in FI will likely overdo the speed of flow, so the colder uppers in the op, likely to be warmed out by T0.

With the SSW unlikely to be useful this side of Winter, if at all, it does look likely that we will have to wait until around mid-Feb to see if we get another repeating cold spell. As for sudden changes, the models seem to be in agreement and are very good at nailing setups like this, especially with no trop-strat link-up.

[nick sussex]

Apart from a few glancing blows of cold which might still get adjusted further east it’s a pretty underwhelming outlook .

The problem remains the PV located where it is , any shortwaves running east engage this and deepen and there’s not enough forcing from the ne to deflect  these further to the se .

These run over the top of the Atlantic high and head into central Northern Europe .

Any colder 850s shown effecting the UK need to be viewed with a pinch of salt  at medium range and can only be relied on if they appear within the day 5 range to counteract model bias .

We need that PV to pull further nw and more amplitude to develop over the eastern USA and Canada .

Unless that happens or the Arctic high to the ne can ridge further sw then it’s going to be a hard slog to get more than just brief colder air into the UK.

[billy]

9 hours ago, BLAST FROM THE PAST said:

What’s of interest to me is how cold we are, have been with fairly benign set ups…especially to recent years.  It has got really cold, coldest Jan night for donkeys down here from a fairly nothing set up.  And projected, there’s some punchy cold to come from the ‘useless’ northerly topplers.  Not what ‘some’ profess

 

 BFTP

Indeed...... -7 yet again here this morning 

[SLEETY]

This High pressure needs to either back further West to allow a Northerly to develop or just clear off all together, all its going to do is bring mild Atlantic gunk over the top of the high and into the uk with its current orientation. 

Really frustrating and eating up precious Wintertime. 

 

[goosey007]

This winter so far gets the thumbs up from me ….had at least 10 harsh frosts which is very favourable to recent years and seen falling snow ….yes no major snow event ….yet but if we do in last 4 or 5 weeks of winter I think 2023 will go down as a fairly memorable one personally ….charts still showing northern cold punches so there is hope down the road …all about perspective when you live in the uk in 21st century not Scandinavia…..

 

 

disclaimer : my perspective won’t stop me hunting for a 3 week deep freeze and multiple blizzard spell on the models …….

Edited January 24, 2023 by goosey007

[Alexis]

Quite different at 240h hemispherically.

GFS has an Aleutian High - bad

ECMWF has an Aleutian Low - good

 

[Penrith Snow]

Dear God, the ECM is awful, it starts  poor and just gets worse with the high shifting eastwards and growing to become a 3000 Mile wide Bartlett sitting over Iberia.

Londoners will be going from scraping ice off their cars to lighting their BBQs on that run.

Didn't look at GFS too depressed.

Andy

PS: All is not lost plenty of snow shots in Greece.....

[bluearmy]

9 hours ago, Vikos said:

Are there any charts for the coupling of tpv and spv available?

this is the gfs op 

Vertical cross u-mean + EPflux

WWW.WEATHERISCOOL.COM

the coupling thing is also complex 

we had a decoupled strat / trop through to the end of December. The upper strat was average to above average and yet the lower strat and trop were decidedly slack 

then we saw the upper strat go into overdrive and it was impossible for the lower strat to avoid the downward pressure from that increase - where else can it go ??

inevitably, once the lower strat goes stronger, the trop can’t avoid an uptick in zonal flow. 

now we see a huge weakening high up and as per the strengthening from higher up, a consequence is the stronger westerlies which were high up are being forced down into the lower strat. There is a notable reversal above 75N but it’s fairly short lived below 10hpa and therefore very unlikely to force any type of reaction further down into the trop regarding any downwelling ‘reversal waves’. tomorrow sees the flow actually go negative in the starting data so we have another day to be 100% certain that there isn’t a late surprise on this into week 2 trop output. 

the 00z runs cut off the n pacific ridge which isn’t great. The eps look to be honing onto a notable nw euro trough end week 2 - how far south that can get not clear.  This trend away from the Azores/Atlantic ridge has been fairly well signalled across the extended fi modelling.  I guess the usual question will be re the euro heights