Model output discussion pm 13/01/2016

[Snowman.]

6 minutes ago, I remember Atlantic 252 said:

FAX for monday looks good, cold/dry, not like GFS

For comparison with UKMO.

Looks very close.

Edited January 14, 2016 by SN0WM4N

[damianslaw]

FAX charts hold the atlantic at bay, with fronts aligned on a NW-SE trajectory with signs of a southerly Jetstream, certainly very different to GFS outputs. The uncertainty continues..

[nick sussex]

Just now, johnholmes said:

True to a degree Nick but to take you up on your first sentence.

How likely is this, as you put it, 'If GFS ejects the low cleanly...'

How likely is this in your view. And, pardon me asking, which low are you talking about please?

 

 

The low is the one ahead of the upstream troughing at T120hrs. This is shown tracking towards the UK and if it separates from the trough will head further se.

In terms of likelihood well given the mess the models have made of things who knows but I was merely pointing out the impact.

This model discussion is not to just stare at the outputs and take everything at face value but also to point out possible evolutions. It hardly takes a huge leap of faith to look at the GFS at that point and reason that it might separate cleanly or it might not.

Its not like pulling out an outcome that needs massive changes, it doesn't.

 

[Snowman.]

10 minutes ago, johnholmes said:

True to a degree Nick but to take you up on your first sentence.

How likely is this, as you put it, 'If GFS ejects the low cleanly...'

How likely is this in your view. And, pardon me asking, which low are you talking about please?

 

 

I believe the he means the one sitting over us or the one off the coast of the America.

 

 

Edited January 14, 2016 by SN0WM4N

[bryan629]

8 minutes ago, essexweather said:

New fax charts:

T+96: http://weather.noaa.gov/pub/fax/PPVM89.TIF

T+120: http://weather.noaa.gov/pub/fax/PPVO89.TIF

Thanks essex... Tuesdays chart is looking rather peachy for an undercut isn`t it...   

I have the latest news on the GFS too >>>>>>>

 

 

[Paul_1978]

16 minutes ago, Ed Stone said:

Not at all...It's just that the weather has the final say. The models are always playing catch-up?

Deary me, does that mean anything?  I'm with @nick sussexon this one- you might as well shut the thread down if you can't make a bit of excitement about the outputs. 

[Nath]

Loving these latest fax charts.  If that low can for once really undercut then it is BOOM

[nick sussex]

12 minutes ago, Banbury said:

Indeed , thoughts on the latest Faxes Nick?

Well they'll probably change by tomorrow! lol Really given the uncertainty its hard to put detail on anything past T72hrs.

In this type of set up just small changes in where the energy goes from troughing upstream makes a very big difference, if more goes se then you trend colder, more ne milder.

[johnholmes]

1 minute ago, Paul_1978 said:

Deary me, does that mean anything?  I'm with @nick sussexon this one- you might as well shut the thread down if you can't make a bit of excitement about the outputs. 

It is also about trying to be objective so that all, especially new folk or visitors, get a reasonable idea on what the odds are on an actual prediction occurring.

A difficult balance and one that does at times lead to tensions on this thread.

[mountain shadow]

4 hours ago, bryan629 said:

Thanks essex... Tuesdays chart is looking rather peachy for an undercut isn`t it...   

I have the latest news on the GFS too >>>>

Under cut what though?  I cannot see high pressure to the North East.  Indeed that fax looks a right mess.

[Pembroke Dangler]

10 minutes ago, bryan629 said:

Thanks essex... Tuesdays chart is looking rather peachy for an undercut isn`t it...   

I have the latest news on the GFS too >>>>>>>

 

 

I would expect a correction west closer to the time, and the undercut taking place further south and west, with the energy joining the Lower pressure over the med as the jet angle is pointing straight at it and one low pressure loves another low pressure as an easy route away from the high over the uk! After that the Azores high will link to the high over the uk and drag the jet ne putting Scotland back in the mild air by Wednesday/Thursday followed by a sinking high.   That's my punt anyway.

Edited January 14, 2016 by Pembroke Dangler

[nick sussex]

I was just thinking its funny you can always rely on the French to make even a NWP model sound much more alluring.

Take the AROME for example, even the ARPEGE.

PS Bryan629 that GFS thing you did was brilliant!

[karlos1983]

9 minutes ago, bryan629 said:

Thanks essex... Tuesdays chart is looking rather peachy for an undercut isn`t it...   

I have the latest news on the GFS too >>>>>>>

 

 

I'm not quite sure what to make of that fax chart! 528 DAM line almost clear of the east coast of UK, lack of heights to our North or North east, or are we thinking it could slip under the heights to our SE and push heights back north? We seem in a middle ground situation, which will deliver slightly less cold drab!

[winterof79]

1 minute ago, nick sussex said:

I was just thinking its funny you can always rely on the French to make even a NWP model sound much more alluring.

Take the AROME for example, even the ARPEGE.

PS Bryan629 that GFS thing you did was brilliant!

Quite,I believe in was on fergies twitter feed earlier in the week

[OldMetMan]

Interesting variations in the model output over several days, basically will the Atlantic systems return once again, which has been the consensus today certainly. But I have been looking at both the upper pattern and surface features with strong HP in polar regions, stretching across the Arctic to N Canada, as well as in mid-Atlantic. Looking at this particular pattern reminds of a number of other occasions where pressure builds SE from Greenland and fends off frontal approaches from the SW.

 

 

There is quite a substantial cold pool developing over W Europe and Scandinavia. The models are sweeping this away far too easily I think, and I expect at least one trough disruption over the SW and subsequent LP activity and the jet taking a more SE path. If this happens, cold air will continue to filter S across Scandinavia strengthening the cold pool.

The appearance of a hurricane in the Azores area is remarkable in January. It may have an impact on Atlantic developments and serve to reinforce the upper low over the W Atlantic and strengthen the mid-Atlantic ridging. 

Over the hemisphere as a whole, there much more of a meridional look to it. I wouldn't be surprised to see the cold air getting more firmly entrenched over the UK with the threat of snow from stalling frontal zones. 

 

 

 

 

[Man With Beard]

14 minutes ago, bryan629 said:

Thanks essex... Tuesdays chart is looking rather peachy for an undercut isn`t it...   

I have the latest news on the GFS too >>>>>>>

 

 

Hmmmm ... Bit of a slide on the fronts close to the UK, then that second low (L999) rushes underneath them... doesn't take a genius to see that it could run into Iberia and leave us in an easterly - which is exactly what happened in Jan 2013. It needs good synchronisation from a few things but it ain't miles off from that chart. Lots more colder members on ECM ens tonight, I wonder if any of them did something similar?

[TEITS]

Before we start looking at the fax charts there is something worth considering and that is the +96/+120 have been wrong these past few days. The reason I say this is because I have been looking at some archive charts and randomly chose the 11th Jan for the 17th Jan. What I have discovered is the UKMO was OTT with regards to blocking whereas the GFS was too progressive in bringing in the Atlantic. If you look at todays output for the 17th then the ECM has been much closer. Worth taking this into account considering the fax charts generally follow the UKMO raw output.

 

 

So a snow to rain event on Monday followed by a return to milder weather from midweek onwards. The UKMO has not been as accurate as some suggest!

Edited January 14, 2016 by TEITS

[Paul_1978]

15 minutes ago, johnholmes said:

It is also about trying to be objective so that all, especially new folk or visitors, get a reasonable idea on what the odds are on an actual prediction occurring.

A difficult balance and one that does at times lead to tensions on this thread.

Point taken John, and apologies if anyone thought my post was raising tensions. However to say "The weather will do what it wants" is a meaningless thing to say on a weather forum IMHO. Only my two penneth. Back under my stone now :-D

[karlos1983]

GFS on its own before going cold later, ECM goes off on one at around the date of interest.

oh well, more runs needed haha

[The Enforcer]

3 hours ago, Nick F said:

EC JET T+132

GFS JET T+132

So, it's the invigorating jet roaring out of the U.S. next week, both agreed on by GFS and EC, that looks to finally put pay to our cold spell, but some uncertainty how quickly this transition will be. Not helped by the models getting jumpy with #Alex.

That Jet streak hasn't reached the UK by Thursday. The Jet over the UK is still heading NW to SE at that point, so why do GFS/ECM show mild Atlantic air piling through on Monday?

[Jason M]

despite the perceived model chaos the one signal that has come through loud and clear is the medium term signal to rebuild euro heights. Of course nothing is certain but the drum beat has been getting louder for some days now. 

Having looked through countless charts, ensemble suites etc two things have stood out to me. Firstly despite the uncertainty I've actually seen very few charts that would deliver what most here are chasing. Even within the ensemble suites there have not actually been many clean hits from deep cold. Rightly or wrongly that suggests to me that such an outcome is unlikely to say the least. Best case is probably a breakdown event. The other notable thing is the euro heights which continue to feature in the background. It does appear that Southern European heights are the drum beat to this winter. I see no evidence that this is going to change tbh and I think at this point despite the short term issues, I suspect that's where we're headed. This is just an educated guess based on what I'm seeing at the moment. Completely respect that others on here have contrary view.

ive just checked the pub run and euro heights feature yet again (albeit a little tease at day 15).

[blizzard81]

18 minutes ago, TEITS said:

Before we start looking at the fax charts there is something worth considering and that is the +96/+120 have been wrong these past few days. The reason I say this is because I have been looking at some archive charts and randomly chose the 11th Jan for the 17th Jan. What I have discovered is the UKMO was OTT with regards to blocking whereas the GFS was too progressive in bringing in the Atlantic. If you look at todays output for the 17th then the ECM has been much closer. Worth taking this into account considering the fax charts generally follow the UKMO raw output.

 

 

So a snow to rain event on Monday followed by a return to milder weather from midweek onwards. The UKMO has not been as accurate as some suggest!

I have always noticed during the last 10 years plus that in similar situations, the fax's nearly always follow the ukmo raw output. In most cases they are wrong.

[Snowman.]

9 minutes ago, Jason M said:

despite the perceived model chaos the one signal that has come through loud and clear is the medium term signal to rebuild euro heights. Of course nothing is certain but the drum beat has been getting louder for some days now. 

Having looked through countless charts, ensemble suites etc two things have stood out to me. Firstly despite the uncertainty I've actually seen very few charts that would deliver what most here are chasing. Even within the ensemble suites there have not actually been many clean hits from deep cold. Rightly or wrongly that suggests to me that such an outcome is unlikely to say the least. Best case is probably a breakdown event. The other notable thing is the euro heights which continue to feature in the background. It does appear that Southern European heights are the drum beat to this winter. I see no evidence that this is going to change tbh and I think at this point despite the short term issues, I suspect that's where we're headed. This is just an educated guess based on what I'm seeing at the moment. Completely respect that others on here have contrary view.

ive just checked the pub run and euro heights feature yet again (albeit a little tease at day 15).

Echoing this and taking it a step further. They also show the re-amplification in our sector with varying degrees of success, right now I'm not thinking much of it due to the current period we're in but I'm going to assume that it isn't handling it perfectly but the outlook is still blocked and I wouldn't rule further attempts at ridging.

Again this is my view but we could see attempted repeats at a blocking scenario maybe one of those will actually deliver and speaking teleconnectively now lots of interest looking forward. 

Edited January 14, 2016 by SN0WM4N

[kumquat]

In retaliation for an unseasonal shot across the bows from Hurricane Alex, the Vortex drops a Bomb on The Canaries.

[Nick L]

What on earth...the latest Euro 4 has decided to thrown in a widespread snow event for Saturday night into Sunday morning. Decent accumulations for much of the Midlands and NW England. Quite simply pulled that out of nowhere.