Model Output Discussion - Into February

[Vikos]

1 hour ago, bluearmy said:

as per the 18z, the 00z also downwells the weaker zonal flow towards the trop at 10hpa - remember, this is the gfs op out to day 16 so expecting it to have the detail correct as the run goes on, especially lower down in the strat is unlikely (although NH zonal flow is not the same as detailed heights ) 

the point is that for two runs we have more of an impending connect with a weaker strat heading down 
 

BA, is it possible that the lower trop is trying to connect to the strat, like an upwelling? Seems to me like the winds in strat are also calming down a bit, so would there be a chance? 

[bluearmy]

3 minutes ago, Mike Poole said:

That 52% was the 18z.  Must admit, i thought it had gone west!  Back to 84% on GEFS on the 0z.

And a much stronger warming with a split on the 0z op, with reversal at T240 - at this point we’d be reaching for the Berlin site to see what the ECM op is showing, but sadly it’s not available this year.  (It’s a bit shaky trusting the ensembles of either model due to lower resolution.)

The ecm op at day 10 is slower than gfs and reasonably in line with the eps mean

  

[Vikos]

7 minutes ago, Mike Poole said:

That 52% was the 18z.  Must admit, i thought it had gone west!  Back to 84% on GEFS on the 0z.

And a much stronger warming with a split on the 0z op, with reversal at T240 - at this point we’d be reaching for the Berlin site to see what the ECM op is showing, but sadly it’s not available this year.  (It’s a bit shaky trusting the ensembles of either model due to lower resolution.)

I wrote Berlin an email but unfortunately I got no answer. Then I called them but you rather get Joe Biden on the phone to talk about bloons made in China then finding someone to talk about stratospheric charts…

Edited February 6, 2023 by Vikos

[bluearmy]

10 minutes ago, Mike Poole said:

That 52% was the 18z.  Must admit, i thought it had gone west!  Back to 84% on GEFS on the 0z.

And a much stronger warming with a split on the 0z op, with reversal at T240 - at this point we’d be reaching for the Berlin site to see what the ECM op is showing, but sadly it’s not available this year.  (It’s a bit shaky trusting the ensembles of either model due to lower resolution.)

The reversal on gfs mean is short lived but likely hides a multitude of solutions - hopefully someone will post them all on the single chart (but even that doesn’t allow for timings.) 

id say that we are currently looking at a short lived tech reversal (as part of a fairly significant wider upper strat reversal ). The spv then recovering back towards the pole in western Siberia but still displaced. this leaves is with a cross polar strat ridge into the Atlantic.  If we can imprint that down through atmosphere into the trop, then with the lower strat westerlies flushed away, late feb and into march offers the best chance of winter since mid dec. 

[January Snowstorm]

Where are Catacol and Carinthian past few days? I would have thought there's enough going on strat wise for a comment... models continue to show benign and indeed quite pleasant weather for the next 10 days. The daffodils will be on the move!

[ANYWEATHER]

2 hours ago, KTtom said:

Ukmo 144... Spring has come early..

 

Strong Diurnal temperatures.  Cold frosty nights with perhaps fog, but some lush sunny days if fog clears and respectable temperatures. ☺

[bluearmy]

38 minutes ago, Vikos said:

BA, is it possible that the lower trop is trying to connect to the strat, like an upwelling? Seems to me like the winds in strat are also calming down a bit, so would there be a chance? 

I don’t see much evidence in the gfs cross sectional but eps flux continues to show up into the strat and we do have wave 1 ongoing at 500 hpa 

 

[bluearmy]

Eps mean back on ssw track T240 to T324

Looks in line with the gefs 

[johnholmes]

Monday 6 Feb

The Noaa ouput from last evening shows a mobile atlantic flow across the atlantic giving a s of w flow into the uk with only the slightest sign of any ridging over n’ern Europe. So probably becoming more unsettled for many n and w’er n areas but fairly settled and less cold than now for se’ern parts of the uk.

Alongside is the 00z 500 mb chart, so at height, the 6-10 day outputs from around 30 th were close to what we have. The issue at the surface was always in doubt even trying to give a =ve view from a cold perspective. Teach me to be totally objective in future-slapped wrists!

please see 500 mb chart on Extra

What happens beyond 6-10 or 8-14 is for others to wrestle with.

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

[SLEETY]

Looking like we are heading towards a repeat of march 1975, very mild February then it turned very cold with repeated heavy snow falls in March, we had two snowfalls here of several inches in March 1975.

Edited February 6, 2023 by SLEETY

[Met4Cast]

Pretty conclusive from the 00z ECM. 

A brief dip in temperatures later this week and then considerably above average air moves in across the UK. Temperatures probably into double digits across the south, a lovely early taste of spring! High pressure could be stuck to our south a fair while.

Edited February 6, 2023 by Met4Cast

[minus10]

Well what is noticeable to me is the ever increasing gap between the mean and long term mean on the ens..

...trending warmer with every run..

Looking at the 0z gfes and ec means for day 10 reinforce this...

...pleasant spring weather in the south ...more unsettled in the n/nw but mild / very mild...

...this also in line with anomalies @johnholmes posted ...

...so whatever is going on with the strat ....down here anything cold looks a rather long way off...might have to embrace an early spring...

 

[ItNeverSnowsInWindsor]

1 hour ago, bluearmy said:

The reversal on gfs mean is short lived but likely hides a multitude of solutions - hopefully someone will post them all on the single chart (but even that doesn’t allow for timings.) 

id say that we are currently looking at a short lived tech reversal (as part of a fairly significant wider upper strat reversal ). The spv then recovering back towards the pole in western Siberia but still displaced. this leaves is with a cross polar strat ridge into the Atlantic.  If we can imprint that down through atmosphere into the trop, then with the lower strat westerlies flushed away, late feb and into march offers the best chance of winter since mid dec. 

just in time for our ski trip in Norway in early March! It’s looking unseasonably mild in Norway this month!

Edited February 6, 2023 by prolongedSnowLover

[carinthian]

57 minutes ago, January Snowstorm said:

Where are Catacol and Carinthian past few days? I would have thought there's enough going on strat wise for a comment... models continue to show benign and indeed quite pleasant weather for the next 10 days. The daffodils will be on the move!

Morning  JS. Aye, been busy digging my home out of piled up snow. Looks like a break now in the weather with sunny but cold days to come over here. I am more of the old school type looking for weather ahead and more interested in a medium term outlook. I am not really into whats going on in the strat but do realize its importance looking long term in winter predictions. However, on so many times developments in that field have looked favourable but never to materialise , so that part of meteorology does not float my boat.  I think , the high is too much north and transient by weekend to become a super mild Barlett high.  Looking at developments to come from the North and East to bring real winter to the British Isles have been a real let down so far. Hopefully, there is a chance of some winter snow if troughing can get in place to the SW coming against the colder block . Thats where I will be watching. 

C

[Stravaiger]

I'm interested in what the ECM's picked up on the last 12 hours. As I feared, the forecast lowering of heights as a lobe of the tPV moved towards us from the NW has been replaced by a renewed surge of heights from the south. But why? What signal has it picked up on that's caused a complete reversal of yesterday's output, which also had support from the GEM.

Hoping it will flip back, but expect that it won't. The AGW curse of relentless high heights will take some breaking.

  

[MattH]

Morning.

Quick post but, overall, still nothing has changed looking ahead, both short-term and long-term and those hoping for late winter weather may still have to pin their hopes on the final third of February or, most probably, March.

We have fallen into the late winter trap of dominant -ve AAM anomalies through the sub-tropics, being propped up by constant WAA over the North Atlantic as the dominant trop PV remains a force to the NW, where it often sits through the late winter, as mentioned a while back any sort of Scandinavian block was never going to happen and, for now, the dominant outlook, as clearly shown by many on here already, is for a sub-tropical/mid-latitude high pressure system to remain influential over W-NW Europe and this won't move very far. The overall AAM profile highlights this pattern quite well, with plenty of -ve AAM anomalies flooding the sub-tropics, note as well the ECM dynamic trop plots, constantly showing a series of anticyclonic wave breaks which will do nothing but simply reinforce the block that many want nearer 60-70N.

The MJO is now on the move and is likely, at a minimum to progress through phases 4 and 5, most probably 6 as well. If your looking for a potential forcing or something to at least mix things up a bit then this may help the cause, but not for at least another 7 to 14 days, which clearly takes us past mid-February. Some of the composite anomalies of the MJO through phases 4-5-6 do bring northern blocking but, as ever, it is never A+B=C and other factors, especially the current dominant tPV may well have some say in this.

The increasingly strong signal for a potential early final warming or a very late winter SSW is gaining traction but, once again this is most certainly not going to immediately deliver synoptics to bring late winter weather any time soon, if at all, especially if it is another displacement event. There is, however, some science behind the risk of synoptics appearing in March that many would have wanted in January and February, how many times have we seen that happen before, especially as seasonal wavelength changes start to come into play as well.

Obviously one could argue the seasonal models have called the late winter pattern correct. There is clearly a connection between a more dominant +ve NAO regime through later winter within a La Nina state and, overall, that has come to fruition, not to the extent it could have, given the blocking pattern over 30-40N currently and lookig ahead, but the winter is likely to fizzle out, overall, IMO. Clearly, winter weather and synoptics can extend beyond February and that clearly does remain a possibility, especially through March, but by then you need some 'proper' synoptics for any significant cold weather and those kind of synoptics can simply delay the onset of spring for many.

Cheers, Matt.

Edited February 6, 2023 by MattH

[Purga]

A grim chart if ever there was one & at odds with the sligtly less ugly 00z

    

[Weather-history]

Spring has sprung on GFS 06z

 

 

[Met4Cast]

2 minutes ago, Weather-history said:

Spring has sprung on GFS 06z

 

 

If the GFS somehow manages to get this right it'll be a wonderful redemption arc for it's awful performance over the last week or so. 

[Penrith Snow]

10 minutes ago, Purga said:

A grim chart if ever there was one & at odds with the sligtly less ugly 00z

    

Wow, follow the 1025mb isobar back from London and its reaches close to the equator!

20c Vallentines day anyone?

[Derecho]

This is turning into a Feb 1998 / Feb 2019 type month. If we can't get a beast from the east then bring it on I say! Reduced heating bills and some nice weather for the outdoors.

[ItNeverSnowsInWindsor]

GFS 6z op is showing the worst outcome with the positively tilted jet. No end in sight at all going into the last week of February either.

Even Scandinavia isn’t immune to the incessant mild weather!

Edited February 6, 2023 by prolongedSnowLover

[LRD]

19 minutes ago, Quicksilver1989 said:

This is turning into a Feb 1998 / Feb 2019 type month. If we can't get a beast from the east then bring it on I say! Reduced heating bills and some nice weather for the outdoors.

Just this minute looked at GFS, ECM and UKMO inc ensembles for ECM and GFS... and, yep, 1998 was the immediate thought that popped into my head

In 1998 we paid for it with a pretty awful spring so I hope that doesn't happen. In 2019 I think spring was ok but can't really remember

But if the models are correct, we look like having another Feb which has more spring-like characteristics than winter ones. Autumn is eating into winter from one end and spring is eating into winter from the other

[johncam]

2 hours ago, ANYWEATHER said:

Strong Diurnal temperatures.  Cold frosty nights with perhaps fog, but some lush sunny days if fog clears and respectable temperatures. ☺

No frosty night here I am afraid 

[Stuie]

Looking for a trend, 9 days out is showing tentative signs of some blocking to our NW.  It is there at day 5 but combined with some NE blocking. This has moved south by day 9 and left the block to the NW.

Whether this would enable cold to come from the NE who knows but better chance that having everything blocked to our north.