Model Discussion - January 17th

[Bristawl Si]

First real signs from the GFS of some colder interludes, with a more southerly tracking jet. Could be signs of a change on its way for end Jan/early Feb.

A good trend me thinks - twists and turns to come in model runs over next few days i reckon.

Edited January 17, 2012 by Bristle boy

[nick sussex]

Interesting NOGAPS at 144hrs, looks very much like the ECM at the same timeframe:

If theres to be a quick way to the promised land it has to come this way, with some retrogression of the pattern and a little trough disruption thrown in for good measure! The below image opens up ok, don't know what happened to the top one!

As you can see I'm still having a few probs with attaching these thumbnails!

Edited January 17, 2012 by nick sussex

[Cecil Hogmanay Melchett]

That is the surface pressure and aint good enough. You want to see oranges and reds signifying height rises at 40,000 feetish where the jetstream is. It is that which blocks the jet.

Whilst the 18z brought a wee northerly, it will not last unless we get proper upper height rises into Greenland. I feel like that is all I'm posting at the moment.

Yes i know exactly what you mean MS.Its just one low after another trundling across the Atlantic.While we see some amplification on 18z its only brief allowing for transient pm incursions.

For all the composites and 10day cpc charts its just a continuation of the zonal theme.I dont think in all my years of model watching i have seen such an aggressive PV and assosiated jet energy.

I remain hopeful of a change at some point i just hope its not too late.

[TEITS]

Latest fax chart at +120 doesn't resemble either the UKMO or ECM.

http://nwstatic.co.uk/fax/PPVO89.png

More of a direct N,ly across E parts. This is much closer to the ECM than the UKMO which is unusual.

Edited January 17, 2012 by THE EYE IN THE SKY

[feb1991blizzard]

At least its a coldish run with some wintry showers possible over Scotland by the weekend, and even to low levels further south next week, that said, i would not bank on anything much further than 120 verifying given the models performance lately.

[Weathizard]

Plenty of upgrades from this latest run, its not brilliant but its a start in the reliable timeframe, lets hope we can build on this in the 00z, not gonna bother looking into FI as the GFS just returns to its default and throws out mega lows from the Western Atlantic.

[No Balls Like Snow Balls]

According to the 18z GFS early next week T120 to T168 (I dare not look any further, and anything past T120 is pushing it) looks very unsettled. It would feel very chilly in the wind almost winter like again lol. Still good heights over greenland. If only the lows would start moving SE we would be in business. Plenty of cold pooling over Northern Scandanavia on this run waiting to come our way hopefully.

[feb1991blizzard]

Yes i know exactly what you mean MS.Its just one low after another trundling across the Atlantic.While we see some amplification on 18z its only brief allowing for transient pm incursions.

For all the composites and 10day cpc charts its just a continuation of the zonal theme.I dont think in all my years of model watching i have seen such an aggressive PV and assosiated jet energy.

I remain hopeful of a change at some point i just hope its not too late.

I would say a pattern change is looking more and more likely now, the PV weakening all the time, height rises will happen to the North at some point, the big problem now is will we be on the right side of meridianality or not.

[Cloud 10]

Subtle variations in the jet profile between the nogaps and gfs. :lol:

nogaps> gfs>

Quite happy with the 18z gfs upto 168hrs,the usual mild outlier in FI though.

[Tom Montalbano]

Latest fax chart at +120 doesn't resemble either the UKMO or ECM.

http://nwstatic.co.uk/fax/PPVO89.png

More of a direct N,ly across E parts. This is much closer to the ECM than the UKMO which is unusual.

Hi Dave,

I take it you meant it wasnt like UKMO or GFS. As you state its quite like the ECM but with a ridge pushing a little further north.. Here's the ECM at t120.

http://www.wetterzentrale.de/pics/Recm1201.gif

Regards,

Tom.

[devon lad]

Charts all over the place atm. GFS 252 Sat 28th 06Z a joke!

dl

[TEITS]

I would say a pattern change is looking more and more likely now, the PV weakening all the time, height rises will happen to the North at some point, the big problem now is will we be on the right side of meridianality or not.

If I had one complaint about the model output it would be the persistance of HP to our S. Ideally in the medium range we really need to see pressure drop around Iberia with the jet tracking further S. This concerns me because with the persistance of the AH is going to force LPs NE.

Going to keep my eye on the NAO because we really need to see this trending negative rather than neutral. Obviously if a negative AO does occur the chances of blocking becoming established forcing the jet further S could result in a lowering of pressure to our S.

[TEITS]

Hi Dave,

I take it you meant it wasnt like UKMO or GFS. As you state its quite like the ECM but with a ridge pushing a little further north.. Here's the ECM at t120.

http://www.wetterzen...cs/Recm1201.gif

Regards,

Tom.

Yes mate although it isn't indentical to the ECM either with the LP near Iceland further W on the ECM. Very unusual because in my experience the Met O follow the UKMO 95% of the time.

[nick sussex]

Subtle variations in the jet profile between the nogaps and gfs. :lol:

nogaps> gfs>

Quite happy with the 18z gfs upto 168hrs,the usual mild outlier in FI though.

At least its backed by the ECM , although of course given recent events that doesn't add that much confidence!

We may get there with the other more traditional route but I'd much rather see the pattern retrogress and that low to the west disrupt.

[Jason M]

If I had one complaint about the model output it would be the persistance of HP to our S. Ideally in the medium range we really need to see pressure drop around Iberia with the jet tracking further S. This concerns me because with the persistance of the AH is going to force LPs NE.

Going to keep my eye on the NAO because we really need to see this trending negative rather than neutral. Obviously if a negative AO does occur the chances of blocking becoming established forcing the jet further S could result in a lowering of pressure to our S.

Spot on IMO. It is near impossible for us to get a major cold spell unless that high clears off. Despite all the background signals it shows no sign of doing so, and like many on this forum i've seen plenty of occasions like this in the past. Personally, I think its just one of those winters where were stuck with a Bartlett type set up and nothing is going to shift it.

[TEITS]

The ensembles are a joke and im only upto member 7 and this is inside +144. Even at +96 im seeing a massive difference. Will explain more when i've had a proper look.

If you want to see trough disruption that Nick S describes then follow the links below!

http://modeles.meteo...-5-1-150.png?18

http://modeles.meteo...-5-1-168.png?18

http://modeles.meteo...-5-1-180.png?18

http://modeles.meteo...-5-1-204.png?18

This is at +120 and not +320!

Fancy a day of settled weather.

What about a storm instead!

Edited January 17, 2012 by THE EYE IN THE SKY

[Duane S.]

The ensembles are a joke and im only upto member 7 and this is inside +144. Even at +96 im seeing a massive difference. Will explain more when i've had a proper look.

If you want to see trough disruption that Nick S describes then follow the links below!

http://modeles.meteo...-5-1-150.png?18

http://modeles.meteo...-5-1-168.png?18

http://modeles.meteo...-5-1-180.png?18

http://modeles.meteo...-5-1-204.png?18

I know.Incredible difference to what we have had to view on the model ops today. I tell you, if run 7 was the always the op the mood in here would be one long party. It always seems rght up there with the best runs every time!

How many times have i watched the operationals run of late and expect an upstream trough to dig in and the evolution to end up more like some of these members show!! Certainly perfectly demonstrates the dillema the Meto are having...

[Zakos]

GFS ensemble agreement remains at all time low. Not that the other models are doing much better. As much as I am not a big fan of the met, i do not blame for sitting on the fence one bit . Its a really tough one to call. I agree with met in that February, and the last few days of jan is either going to be significantly above, or significantly below average. I cannot see a continuation of cool zonality which the gfs suggests. I for one am completely ignoring the models beyond 180 hours atm, I am just going to see what more knowlegable and experienced people have to say about it. Fax charts will also be intersting, as its times like these where the human input is very valuable.

[bobbydog]

-5 uppers into northern france by next wednesday morning.

i dont care!! i dont live in france!! i want snow!! make it snow!! wahaahaaa!!!!!!

[TEITS]

Last one from me tonight.

After tonights 12Zs I was pretty sure the model output had finally sorted itself of. However after the +120 fax chart and the 18Z GEFS ensembles I have to say the outlook continues to be uncertain. The ensembles appear to struggle as early as +96 with regards to LP around Iceland and the depth and track of the LP. The only trend I could spot in the madness of those ensembles as is they appear to have intensified this LP and track it closer to the UK on a more SE,ly track rather than a ESE,ly track.

So don't be surprised if come tomorrow morning the UKMO/ECM might look different between +96/+144.

[Duane S.]

And anybody that still wants to cling onto the notion that somehow we are going back to a November pattern, this of course will not necessarily send cold to the UK but it will go a long way to seeing through the pattern change I suspect...

At 10hpa level (where it should be in June)

Lower down at 30hpa (where it should be in May)

[Zakos]

And anybody that still wants to cling onto the notion that somehow we are going back to a November pattern, this of course will not necessarily send cold to the UK but it will go a long way to seeing through the pattern change I suspect...

At 10hpa level (where it should be in June)

Lower down at 30hpa (where it should be in May)

where the hell did that come from!!? That looks like an error its such a ridiculous leap!! Surely this is a SSW? I have no knowlege of stratospheric temps effects on our weather. But i gather this very, very good news?

[summer blizzard]

where the hell did that come from!!? That looks like an error its such a ridiculous leap!! Surely this is a SSW? I have no knowlege of stratospheric temps effects on our weather. But i gather this very, very good news?

There have been multiple wave breaking events in recent weeks although this one has managed to get through.

Not a technical SSW because zonal winds have not reversed.

[Feeling Frosty]

Is it true that there has been a major error with the computer models? If so how far back?

EDIT: I think it's a false rumour based on the Internet going down earlier (Virgin Media)

Edited January 18, 2012 by Feeling Frosty

[KTtom]

Hmm, GFS 00Z just beginning to look a little cold at the end of January with an initial northerly followed by an easterly at the end of the run...normal practise would be to laugh at the run but after yesterdays Metoffice bombshell... :smilz38: