Model Output Discussion - Happy New Year!

[Easton Luna Boys]

5 minutes ago, PDM said:

Thats some high moving in overr the next few days at around 1047mb would take some shifting. 

Yes, just need it to slip slap bang over us for an extended spell of clear, dry calm conditions, with the possibility of some faux cold for the cold boosters to look forward to. 

Likelihood though will be an infiltration of more humid air into the mix, giving a dirty high. Both options though are appealing to me. 

[Allseasons-Si]

Well the ECM is nothing like the gfs at 192....but the high is retrogressing west so should produce a NW'ly flow.

Edited January 15, 2020 by Allseasons-si

[weirpig]

6 minutes ago, Allseasons-si said:

Well the ECM is nothing like the gfs at 192....but the high is retrogressing west so should produce a NW'ly flow.

Indeed  I know we have heard it before  but could be a good 240h

[Jeremy Shockey]

GFS 12 z control @ 240

So what happens after our dry , settled , hopefully frosty spell of about 7 days duration dominated by the 1045 UK High ?

I wouldn't mind the GFS 12z control @ 240hrs.

[BlueHedgehog074]

At 240 hours, the 12Z ECMWF maintains a flow from the North-West. A deep Low to the North of the UK and High Pressure pushed a bit further away South and South-West of the UK. So staying on the chilly side.

Showers cold enough to be wintry over low(ish) ground over Northern UK. 10 days away so likely to change. A North-Westerly may not happen at all, but at the same time, there is room for some of these Polar Maritime flows to become more potent. A chance as well maybe for some Arctic Maritime air could mix in. Depending, however, on whether enough amplification can develop upstream and getting a quality Atlantic ridge to form.

Edit: a bit like that GFS control run that Jeremy posted above.

Edited January 15, 2020 by DiagonalRedLine

[Jeremy Shockey]

UKMO 12z 144

UKMO 12z 168

I know these charts are not very clear , but always interesting to see where the HP might go on day 7 according to the UKMO

Edited January 15, 2020 by Jeremy Shockey

[mb018538]

ECM 240 certainly looks promising, with at least the chance of a temporary cold blast with some snow. Depends how it all lines up, but one to watch again....

[IDO]

3 minutes ago, mb018538 said:

ECM 240 certainly looks promising, with at least the chance of a temporary cold blast with some snow. Depends how it all lines up, but one to watch again....

Yes, all models indicating a trough dropping close to the UK within the westerly flow circa D10. But transient and too far out to know if we just get the colder uppers from the ridge/high or a glancing blow from the lower heights and maybe some snow to the lucky ones?

Looking at the GEFS and ECM means, they have arrived:

...to a more mutual place. That is pretty solid for D10 mean charts and suggests that the current modelling will verify well. So maybe an upper air cold flow for a day or so before the pattern flattens out as the GEFS mean suggests and no reason not to expect similar on the EPS. 

All in all, just what we would expect from an average UK January winter at some point.

[bluearmy]

Note the gefs control goes pretty wintry looking .......the eps control is a veritable snowfest this winter in the extended with systems running south in the n flow before a cold Atlantic ridge moves in end week 2 

[snowking]

Looking at the ensembles I am increasingly confident that the coldest period of the winter will come between 28th Jan - 2nd Feb.

Why? Because I am out of the country

[northwestsnow]

10 minutes ago, bluearmy said:

Note the gefs control goes pretty wintry looking .......the eps control is a veritable snowfest this winter in the extended with systems running south in the n flow before a cold Atlantic ridge moves in end week 2 

There is scope for  a North westerly around day 10.....

Smart money on the Azores high ridging NE cutting off any colder air fairly quickly.

Perhaps northern elevated at risk of something wintry?

Edited January 15, 2020 by northwestsnow

[That ECM]

Just now, snowking said:

Looking at the ensembles I am increasingly confident that the coldest period of the winter will come between 28th Jan - 2nd Feb.

Why? Because I am out of the country

Or why? Because it hasn’t been cold and it’s got nothing to beat

[Allseasons-Si]

Finally starting to see a cooler trend at the end of the eps ens and a mean flow from the NW

let the upgrades continue,we have been waiting for a long time,it payback time.

 

 

[Mike Poole]

I took a good look at the models on Sunday, how much has changed, maybe not too much, as you might expect with a 1045 high taking centre stage.  

Let's start with the ECM, here T240:

Promotes a northwesterly flow that could be cold for some.  Worth considering in the context of the ensembles though, here the mean and spread at T240:

From the mean it can be seen that the vortex remains displaced away from Canada for the foreseeable (I'm not a fan of longer timescale T384 means, by the way, when the uncertainty is earlier).  In our neck of the woods, the mean may look flat, but the spread suggests uncertainty and that a number of ensemble members have a more amplified Atlantic ridge, euro trough.  Will be interesting to see the clusters on this suite later.

Rowing back a bit, the main models at T144:

In terms of amplification at this point, UKMO, ECM, GEM, GFS is the pecking order, I therefore feel the GFS is underdoing this one.  I kind of feel like waiting until this UK high actually happens before worrying about what other systems are where, and where it might lead, and look again at what the models are saying at that point - by which time we might have more certainty with the MJO progression, here's today's GEFS:

One's eye is drawn to the endpoint, but I've noticed recently that practically every day a model prediction point is replaced with the actual thing, it is ever so slightly more amplified.  Which suggests the models are still getting to grips with the pattern, rather than showing random variation about a mean...which means there is continued interest, even if the best outcome at the moment for cold is a two to three day northerly...we will see.

[damianslaw]

Entering what is generally the coldest core period of the year, mid Jan - mid Feb, and also a time when the atlantic begins to quieten from its early winter stirrings (not all years, but typically it does)..

What do we have in store, a change to something a bit colder in the nearer term, and thankfully something quieter as well, with a significant sudden surge of high pressure building through the UK this weekend, up to close to 1050mb which is very strong. A return to air frost and sunshine, which will be welcomed by many I'm sure, after weeks of mainly dull overcast drab dank skies.

The models continue to show the direction of travel as we move through latter part of the month is from the NW, the high set to back south west, with the strong jet riding over the top. No surprise to see the models showing some potent polar air invading the UK in the 10 day timeframe, much will depend on the position of building heights, if these stay closer to the UK, then a glancing not quite so cold flow will envelop, a bit further west then a preety cold blast will follow suit. Longer term, we could see the high ridge back in again.

 

[nick sussex]

3 hours ago, IDO said:

If we expect the MJO signal to verify we had a strong phase 5 from the 10th to 14th that should be showing up in the models. Does this tally with the composites?

If it does then we can have better confidence in phase 6 and 7? Judah Cohen also believes the MJO remains a non-driver and is now saying it is a "PV reflection" AKA Stratospheric wave reflection; currently in progress (pros maybe able to decipher this?). I am struggling to match the composites with the MJO cycle using a 10-day lag! Maybe missing something? 

I suspect the tPV apparently at its most brutal will be tough to break through for any HLB'ing. That tPV looks a beast till into February as currently modelled by GFS; D13:

Getting any heights near Greenland looks a hard call with that profile.

Judah Cohen and Michael Ventrice  seem to be obsessed with trying to trash the MJO as a false signal .

JC has now gone into pretentious twaddle mode with his Stratospheric Wave Reflection ! And MV earlier was droning on about westerly wind bursts , implying the MJO was false when the research shows WWBs are often associated with strong MJO events but crucially its often tropical cyclones aided by the MJO which help to induce the said WWBs in the first place ! 

The OLR ( outgoing longwave radiation) shows the  MJO signature and the expert at NOAA has stated the MJO exhibits a clear wave 1 pattern , so typically the area of increased and suppressed convection characteristic of the MJO.

They seem to be arguing that the MJO isn’t happening because other factors are happening at the same time . 

I’m not for a moment saying that MV and JC aren’t we’ll known experts but we seem to be dealing with a debate over what constitutes a real MJO event.

NOAA seem sure it’s a real one and have said they expect it to impact the pattern in the USA which in turn will have an effect on us in Europe downstream .

I suppose it’s a case of a wait and see .

 

 

 

[tight isobar]

ahh -gwan then!!.

finally  be see some  belly flippers via ensembles  ..

 

and Epson offering up a solution  to cold..

the bets are after initial  hp  encroachments. ..a transition  to a polar maritime  classic  northwesterly flow! !!

 

then as we gain. ..there is more than ample  for mlb  and a transfer to real polar outbreak! !!

 

with the givenue format  solutions  to perhappen a Scandinavian  block plot.

winter most certainly  may have a sting in the tail....with the very best saved  till last!!!

 

transition  definitely  today's byword! !!

Edited January 15, 2020 by tight isobar

[tight isobar]

5 minutes ago, nick sussex said:

Judah Cohen and Michael Ventrice  seem to be obsessed with trying to trash the MJO as a false signal .

JC has now gone into pretentious twaddle mode with his Stratospheric Wave Reflection ! And MV earlier was droning on about westerly wind bursts , implying the MJO was false when the research shows WWBs are often associated with strong MJO events but crucially its often tropical cyclones aided by the MJO which help to induce the said WWBs in the first place ! 

The OLR ( outgoing longwave radiation) shows the  MJO signature and the expert at NOAA has stated the MJO exhibits a clear wave 1 pattern , so typically the area of increased and suppressed convection characteristic of the MJO.

They seem to be arguing that the MJO isn’t happening because other factors are happening at the same time . 

I’m not for a moment saying that MV and JC aren’t we’ll known experts but we seem to be dealing with a debate over what constitutes a real MJO event.

NOAA seem sure it’s a real one and have said they expect it to impact the pattern in the USA which in turn will have an effect on us in Europe downstream .

I suppose it’s a case of a wait and see .

 

 

 

ventrice  and Cohen are usually a loggerheads via upper dynamics. ...though there on the same sheet on this 1...@mjo-forcing. ...I'd have to agree...also..the dynamic  has already  been overridden  really...as most outs are showing!!!

Edited January 15, 2020 by tight isobar

[nick sussex]

2 minutes ago, tight isobar said:

ventrice  and Cohen are usually a loggerheads via upper dynamics. ...though there on the same sheet on this 1...@more forcing. ...I'd have to agree...also..the dynamic  has already  been overridden  really...as most outs are showing!!!

I didn’t realize they weren’t on the same page normally . Regardless even if an event turns out to be rubbish it’s still an event ! If for example the MJO is being over ridden by other factors , if the MJO happened it happened ! 

Given the time lag how would we know the MJO hadn’t impacted the NH pattern until after said time lag had passed .

Anyway I’m keeping an open mind . Let’s see what transpires .

[tight isobar]

1 minute ago, nick sussex said:

I didn’t realize they weren’t on the same page normally . Regardless even if an event turns out to be rubbish it’s still an event ! If for example the MJO is being over ridden by other factors , if the MJO happened it happened ! 

Given the time lag how would we know the MJO hadn’t impacted the NH pattern until after said time lag had passed .

Anyway I’m keeping an open mind . Let’s see what transpires .

well it is...there and a signal tool. 

although  1 imo  that's relied  on a tad too much as a mass impatual  nor -hem tool  /deciphering. ..

 

although wise words. .

@keeping an open mind

and we can indeed revert bk5..when any lagging is/has played out.

[IDO]

14 minutes ago, nick sussex said:

Judah Cohen and Michael Ventrice  seem to be obsessed with trying to trash the MJO as a false signal .

JC has now gone into pretentious twaddle mode with his Stratospheric Wave Reflection ! And MV earlier was droning on about westerly wind bursts , implying the MJO was false when the research shows WWBs are often associated with strong MJO events but crucially its often tropical cyclones aided by the MJO which help to induce the said WWBs in the first place ! 

The OLR ( outgoing longwave radiation) shows the  MJO signature and the expert at NOAA has stated the MJO exhibits a clear wave 1 pattern , so typically the area of increased and suppressed convection characteristic of the MJO.

They seem to be arguing that the MJO isn’t happening because other factors are happening at the same time . 

I’m not for a moment saying that MV and JC aren’t we’ll known experts but we seem to be dealing with a debate over what constitutes a real MJO event.

NOAA seem sure it’s a real one and have said they expect it to impact the pattern in the USA which in turn will have an effect on us in Europe downstream .

I suppose it’s a case of a wait and see .

Yes, all very complicated and I agree that time will answer this. Certainly murmurings in the suites of something occurring but too early to be sure. Need the echoes to get louder rather than fade away as they have done so far this winter. 

Certainly the Met update (today) for the month ahead, zero mention of any blocking, pretty much the status quo of euro high affecting the south and the north subject to the zonal flow (week 3-4). Not really a reflection of the MJO composites. So we will see...

[Singularity]

To be fair, the MJO event does appear to be lacking in certain components, especially in the Northern Hemisphere, which will limit its ability to influence our weather patterns.

So, we see the subtropical highs tending not to make it beyond mid-latitude status. Meanwhile, the tropospheric 'polar vortex' looks to become focused toward Siberia for a time, but without some HLB to its west, this makes for a very unstable N. Atlantic, with cyclogenesis there giving the UK a hard time tapping into much cold air.

You never know though, we could get lucky with a 'runner' into the base of the major trough to our NE. Not something to place bets on - just worth keeping an eye out for.

[Stuie]

22 minutes ago, tight isobar said:

ahh -gwan then!!.

finally  be see some  belly flippers via ensembles  ..

 

and Epson offering up a solution  to cold..

the bets are after initial  hp  encroachments. ..a transition  to a polar maritime  classic  northwesterly flow! !!

 

then as we gain. ..there is more than ample  for mlb  and a transfer to real polar outbreak! !!

 

with the givenue format  solutions  to perhappen a Scandinavian  block plot.

winter most certainly  may have a sting in the tail....with the very best saved  till last!!!

 

transition  definitely  today's byword! !!

Finally an 850 chart for London with serious -10 members, time to get interested, again, finally.

[nick sussex]

3 minutes ago, Singularity said:

To be fair, the MJO event does appear to be lacking in certain components, especially in the Northern Hemisphere, which will limit its ability to influence our weather patterns.

So, we see the subtropical highs tending not to make it beyond mid-latitude status. Meanwhile, the tropospheric 'polar vortex' looks to become focused toward Siberia for a time, but without some HLB to its west, this makes for a very unstable N. Atlantic, with cyclogenesis there giving the UK a hard time tapping into much cold air.

You never know though, we could get lucky with a 'runner' into the base of the major trough to our NE. Not something to place bets on - just worth keeping an eye out for.

Interesting you should say that . A lot of the debate surrounding the MJO is often what measure is the best judge . Be it OLR or some of the others . Even if we don’t get HLB we could see any mid latitude high edge west allowing the jet track se into the UK around the top of that .

[Singularity]

2 minutes ago, nick sussex said:

Interesting you should say that . A lot of the debate surrounding the MJO is often what measure is the best judge . Be it OLR or some of the others . Even if we don’t get HLB we could see any mid latitude high edge west allowing the jet track se into the UK around the top of that .

Indeed - from observations it's become apparent to me that some events are more convection/precipitation-dominated (OLR/VP200 measurements), others wind pattern-dominated (zonal wind anomalies), while some find a good balance between the two. 

It generally seems (at least in my experience) that the more of these components are strong, the more impact the MJO event tends to be on N. European weather patterns if and when it travels past the Dateline.