Model Output Discussion - New Year and Beyond

[mbrothers]

10 minutes ago, swfc said:

Looking in the reliable time frames it all looks again bog standard weather. Dry is good granted but barring the 10hpa outlook its just an area of high pressure drifting about? Does anyone think cold without snow is like heat without subshine

No

[Catacol]

4 hours ago, Bricriu said:

Just in relation to mid February cold chances, is the MJO by then predicted to be in a phase favourable for blocking? 

Depends how fast it moves. Usually 30-60 days cycle - so we were phase 7 first week of Jan. Mid Feb certainly possible to repeat. What is notable is the strength of the MJO this season in a Nina ENSO context. Quite active and certainly active right now in the IO (Indian Ocean)

There are many possible combinations of late winter patterns lining up for us in this very interesting winter. MJO progression is one element. Shape of SPV disruption and whether it splits, displaces or does neither is another and I continue to hold my breath on this. Timing of next pacific jet extension will play a part linked to future EAMT events, hard to forecast. 

But at least we are in the game. Someone earlier said that the single element definitely absent for the end of this month and heading into February is a strong SPV connecting to a strong TPV and driving westerlies. Whatever else happens going forward that is a good starting point.

[minus10]

On the face of it this doesnt look like a bad EC 500 anom 12z..10 day

...higher than average heights stretching from south of Greenland accross the Pole to the Aleutian side with lower than average heights in most of med and to the west of Spain..helping to weaken or split the trop vortex??....however we know that anomalies can be deceptive ... except that the actual mean i think is not a million miles away from this...

...mmm....

 

[tight isobar]

3 minutes ago, swfc said:

Looking in the reliable time frames it all looks again bog standard weather. Dry is good granted but barring the 10hpa outlook its just an area of high pressure drifting about? Does anyone think cold without snow is like heat without subshine

Won’t take a lot to draw in a more “ moisture based sourcing. I can understand the emphasis/ frustration in the Synoptics! - 1 thing is nailed pretty much... is an expansive HP rounding itself from biscay upto Iceland into the Atlantic!.. I don’t think I need to go in-depth much more  for the notions of the different play outs should (which is likely)- the switch n, direction of the placed high would make!!.. we’ll watch with interest... I certainly will

[Don]

26 minutes ago, swfc said:

Looking in the reliable time frames it all looks again bog standard weather. Dry is good granted but barring the 10hpa outlook its just an area of high pressure drifting about? Does anyone think cold without snow is like heat without subshine

No it's far better than that, albeit I get it's very frustrating!!

[bluearmy]

 Very interesting eps T300 ……..

[Catacol]

19 minutes ago, minus10 said:

On the face of it this doesnt look like a bad EC 500 anom 12z..10 day

...higher than average heights stretching from south of Greenland accross the Pole to the Aleutian side with lower than average heights in most of med and to the west of Spain..helping to weaken or split the trop vortex??....however we know that anomalies can be deceptive ... except that the actual mean i think is not a million miles away from this...

...mmm....

 

It's a decent looking anomaly and mean combo. We have all seen much worse. The frustration overall - unless in the far north or fortunate spots that have come good - is that 2 cold spells so far this winter are not looking like they will produce widespread snowfall. I'm yet to see a single flake and didnt see one either last year! Both cold spells (early Dec and now mid Jan) have produced more depth of cold than many might have expected prior to their arrival but lack of precipitation is noticeable because both cold patterns have been pretty stagnant. It really is tough in the UK to get things to click for snow.

Retrogression of the pattern as momentum drops now strongly backed by the ensembles, but the blocking signal looking more mid than high lat. 

The mid lat option as this frosty spell this week comes to an end is looking increasingly favoured. Still thinking the biggest player going forward from here will be the rebounding impacts of changes to the SPV. And one thing is for sure - if the SPV does take a really significant hit (and ideally split) then bin all and any NWP forecasts at long range because they genuinely won't have a scooby as to what happens next. NWP modelling has a lot more vertical resolution than was the case in the past but is still a long way from being able to predict accurately speed of downwell and/or movement of vortex shards. Anomaly forecast for the SPV continues to move in the right direction:

And this means I dont think anyone can predict what is going to occur out beyond 240h at the moment. Crossroads moment, buckets of uncertainty.

Edited January 17, 2023 by Catacol

[RhHh]

Where do we get the snow depth charts from please? I know they are pure rubbish but I need some hope to cling to!

[Tim Bland]

13 minutes ago, RhHh said:

Where do we get the snow depth charts from please? I know they are pure rubbish but I need some hope to cling to!

There are no snow depth charts for Gatwick that are going to give you any hope at the moment !

[Kirkcaldy Weather]

Definitely one of the first focus points continues to be the block retrogression then linkup to the Pacific blocking leading to that elongated trop vortex extending in our direction from the NE 

 

 

 

 

[Mike Poole]

8 minutes ago, Kirkcaldy Weather said:

Definitely one of the first focus points continues to be the block retrogression then linkup to the Pacific blocking leading to that elongated trop vortex extending in our direction from the NE 

 

 

 

 

Yes, I agree, it is the one clear signal in amongst the noise from T240 onwards.

I am struggling to get a feel for the timescales over which I expect to see some results of the strat malarkey in the output for down here in the trop.  There is both the flushing down of westerlies, followed by downwelling of easterly winds - potentially, but it is confounded by the warming seeming to occur in the strat in several stages leading to (most likely?) a gradual displacement (rather less of a sudden SSW, if the 60N zonal wind reversal does happen with that scenario), then there’s what happens if a split occurs - something more dramatic.  

I think I’m sort of saying that I’m not sure the timing’s right for those charts you post to be a direct result of the strat warming, rather too quick, but I’m not sure.  On the other hand, the other members that cap us off at a UK high may be seeing the flushing of westerlies.  

Anyway, just musing - wonder what the pub run has in store?

[Blizzardof82]

39 minutes ago, RhHh said:

Where do we get the snow depth charts from please? I know they are pure rubbish but I need some hope to cling to!

If you go on Meteociel and go to GFS click on Hauter Niege 

[Don]

29 minutes ago, Tim Bland said:

There are no snow depth charts for Gatwick that are going to give you any hope at the moment !

Almost as bad as here!! 

[RhHh]

4 minutes ago, Blizzardof82 said:

If you go on Meteociel and go to GFS click on Hauter Niege 

Cheers!

[Ali1977]

Heights building into Greenland at T186, could be better this run 

[Guest]

The trend in the 10 day period is clearly towards a UK high so lots of dry and quiet weather coming our way:

[Don]

Just now, lassie23 said:

Is it looking dire again When is this scandi high going to turn up fgs

April?! 

Just now, Tidal Wave said:

The trend in the 10 day period is clearly towards a UK high so lots of dry and quiet weather coming our way:

At least pressure remains lower over the Med.

[bluearmy]

22 minutes ago, Mike Poole said:

Yes, I agree, it is the one clear signal in amongst the noise from T240 onwards.

I am struggling to get a feel for the timescales over which I expect to see some results of the strat malarkey in the output for down here in the trop.  There is both the flushing down of westerlies, followed by downwelling of easterly winds - potentially, but it is confounded by the warming seeming to occur in the strat in several stages leading to (most likely?) a gradual displacement (rather less of a sudden SSW, if the 60N zonal wind reversal does happen with that scenario), then there’s what happens if a split occurs - something more dramatic.  

I think I’m sort of saying that I’m not sure the timing’s right for those charts you post to be a direct result of the strat warming, rather too quick, but I’m not sure.  On the other hand, the other members that cap us off at a UK high may be seeing the flushing of westerlies.  

Anyway, just musing - wonder what the pub run has in store?

Maybe we won’t see a large enough reversal high up (ref size and affecting below 70N) to downwell easterlies into the trop - however, if we see enough of a reversal to force some westerlies down then perhaps we could then expect the strat profile to imprint onto the trop?? I’d take that for early feb at the moment 

Edited January 17, 2023 by bluearmy

[blizzard81]

2 minutes ago, Don said:

April?! 

At least pressure remains lower over the Med.

Yep. No Euro high gives us a fighting chance. 

[Guest]

3 minutes ago, Don said:

April?! 

At least pressure remains lower over the Med.

Aye, need the jet to the north to take a breather.

[frosty ground]

6 minutes ago, Tidal Wave said:

The trend in the 10 day period is clearly towards a UK high so lots of dry and quiet weather coming our way:

A fair assessment 

[Trom]

24 minutes ago, Mike Poole said:

Yes, I agree, it is the one clear signal in amongst the noise from T240 onwards.

I am struggling to get a feel for the timescales over which I expect to see some results of the strat malarkey in the output for down here in the trop.  There is both the flushing down of westerlies, followed by downwelling of easterly winds - potentially, but it is confounded by the warming seeming to occur in the strat in several stages leading to (most likely?) a gradual displacement (rather less of a sudden SSW, if the 60N zonal wind reversal does happen with that scenario), then there’s what happens if a split occurs - something more dramatic.  

I think I’m sort of saying that I’m not sure the timing’s right for those charts you post to be a direct result of the strat warming, rather too quick, but I’m not sure.  On the other hand, the other members that cap us off at a UK high may be seeing the flushing of westerlies.  

Anyway, just musing - wonder what the pub run has in store?

I seem to remember from previous events that the impact on the trop was not initially well modelled by any of the models and led to periods of volatility in output before things settled down.

[blizzard81]

Interesting period of model watching. Most roads lead to some form of UK high around days 9 to 10. At odds with the Exeter update today. 

[BLAST FROM THE PAST]

 

Major northerly plunge coming?  Or a big fat HP over us…with very chilly nights

BFTP

Edited January 17, 2023 by BLAST FROM THE PAST

[blizzard81]

After day 10. Who knows? I suspect very few, if any have a scooby. Hopes will be high no doubt but it could easily be a case of limpet UK high giving some tepid frosts, slowly sinking south east. I will expect this but hope for so much more. Best way to keep grounded and avoid disappointment.