Model Output Discussion - 14th Jan 12z Onwards

[chris55]

Remember we are entering a phase of more blocked conditions with colder air becoming entrenched. The models will ALWAYS struggle with the longer evolution from such a set up. I have seen it many times. That's not to say things will end up either continually colder or milder just that until we head into next week the mid term will not be nailed. far from it.

Edited January 15, 2015 by chris55

[Mucka]

I noted it this morning after the 00z GFS and UKMO. I'd much rather take a much more marginal situation with energy continually sliding NW-SE than the 'flash in the pan' easterly quickly followed by a roaring northern jet and back into status quo territory. If we reset westerly then where is the next cold spell materialising from because pretty soon we'll be heading towards Feb.

 

The issue I have is that some places now look like missing out double whammy style....i.e slider too far west followed by a brief easterly which doesn't entrench long enough for anything of prolonged note.

 

 

We have suffered such frustration many times in the NW unfortunately. JMA and UKMO though could offer the best of both worlds. ECM though very cold wouldn't be good for many re snow chances. We will just have to take what comes.

[blizzard81]

Yeah I must of missed that, these SW'erly winds sure look balmy.

viewimage (1).png

viewimage (2).png

Don't get me wrong, there is an easterly - JUST! for all of 24 hours and it is by no means a classic easterly. Not saying there isn't time for the outlook to change but like I said earlier, just relaying my thoughts on the trends of the 12z ops.

[blizzard81]

Paul Hudson has just mentioned an Easterly by mid week. It may not last long, but it's certainly not a 'distant dream' as it's showing on all models

 

last post until 2pm

calm down dear, it's only the weather!

[SteveB]

On thing for sure, Scotland  sure looks cold, look at the temps at 3pm Sat

 

 

 

Snow moving down through the spine if the country Saturday

 

 

More snow Sunday morning & feeling a tad chilly up North

 

 

Very cold again (especially Scotland ) Monday morning.

 

Ireland gets a pasting later on  Monday

 

As for the rest of the week, staying cold with more snow chances for most if not all.

 

 

 

I'm sure it will change before now & then, but the general theme is there, COLD & SNOWY

[Cheshire Freeze]

Remember we are entering a phase of more blocked conditions with colder air becoming entrenched. The models will ALWAYS struggle with the longer evolution from such a set up. I have seen it many times. That's not to say things will end up either continually colder or milder just that until we head into next the mid term will not be nailed. far from it.

 

The issue is the NWP doesn't appear to be struggling tonight? From what I can see there appears reasonable cross model support that any E'ly will be a brief affair before the high topples to a mid lat position. Chances of reverting to something more sustained circa 10% IMO as I've rarely seen this happen once the models latch on to a toppling scenario. In fact 10% is being generous. Put it this way, I'd be stunned if we saw a reversal of the trend witnessed today.

 

The fact that not even Steve Murr can post the day 10 ECM chart with a positive is a true indictment of just how filth that scenario is.

Edited January 15, 2015 by CreweCold

[Bristawl Si]

Cold "snap" ; cold "spell".

Anything over 4 to 5 days is a "spell" in my book.

So from this evening onwards i reckon next 7/8 days means it'll be a cold spell.

[nick sussex]

I hope this thread isn't going to descend into despondency or chaos because of the ECM.

 

You simply can't trust an operational output that goes from this on its 00hrs run:

 

T192hrs:

 

 

T168hrs on the 12hrs:

 

 

Although we don't have the 12hr steps theres a chasm between both runs, I think we best wait to see the ECM spreads and ensembles later on.

[SE Blizzards]

Yes, but longevity was always open to doubt: yesterday's JMA caught our eye by faster exit from colder phase; MOGREPS later, but much milder ultimately. The chosen middle ground was thus to talk of a gradual waning of cold and rtn back towards around average in the 10-15d period, but with considerable uncertainty (which clearly remains).

 

Well, let's hope tonight's JMA catches your eye...

 

 

 

Not much sign of a fast exit of colder phase there.

[Cloud 10]

The ECM at day 10 and earlier is out of kilter with the 00z ensemble mean with those low heights around Greenland,so could be a shredder job from day 7 onwards.

 

12z op..  00z mean..

[Ali1977]

Yes, but longevity was always open to doubt: yesterday's JMA caught our eye by faster exit from colder phase; MOGREPS later, but much milder ultimately. The chosen middle ground was thus to talk of a gradual waning of cold and rtn back towards around average in the 10-15d period, but with considerable uncertainty (which clearly remains).

Has today's JMA caught your eyes too, looks about the best for us coldies on this evenings offerings.....The JMA long range also showing huge blocking for Feb.

Edited January 15, 2015 by Ali1977

[Woollymummy]

In the mean time, here is some light after-dinner reading material from the netweather library, in case you are new to these things, like me!:

https://forum.netweather.tv/topic/27989-how-to-try-and-forecast-snow/

[swfc]

The issue is the NWP doesn't appear to be struggling tonight? From what I can see there appears reasonable cross model support that any E'ly will be a brief affair before the high topples to a mid lat position. Chances of reverting to something more sustained circa 10% IMO as I've rarely seen this happen once the models latch on to a toppling scenario. In fact 10% is being generous. Put it this way, I'd be stunned if we saw a reversal of the trend witnessed today.

Tbh i think the chances of any decent blocking to the north or east were a long shot looking at the nhp all week.Just looks pv wise that its not realistic to see a strong block building to the east at this time.There does look a window of opp for a rise in pressure towards iceland-svalbard which as you said would give us the continues slider scenario.Id take that option looking at the set up to the east ete.

[BLOWERS]

Tut tut mods feel free to remove I do not post on here much prefering to sit on the fence and watch from behind the scenes and leave it to the most experienced on here,i do feel that the mod thread is fast becoming the south thread,when a person from the north west comes in and gets slated for commenting the north west is gping to have loads of snow,i do feel the mods need to get a hand on this it is very much becoming imby yet again.Thanks

Clearly the mods have it all on to 'police' every post, but it's a right royal pain scrolling through all the dross to find a knowledgeable/interesting one ABOUT THE MODEL OUTPUT! If I'm posting this in the wrong place, I hold my hands up, but is there any way to build a filter into the forum so we can select (if we want to) a chosen few posters who we know usually talk relevant sense?! And (off topic) if I see 'anomalies' spelled 'anomalys' again, I fear the consequences...

[johnholmes]

In the mean time, here is some light after-dinner reading material from the netweather library, in case you are new to these things, like me!:

https://forum.netweather.tv/topic/27989-how-to-try-and-forecast-snow/

 

It does work-honest, the first requirement of course is that the model shows ppn over your backyard, if it does not it does not matter how many other ticks you have it will not snow!

[SMU]

ECM 240 -

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015011512/ECH1-240.GIF?15-

 

Split energy in the atlantic looks to ensure another cold push from the East @ 264...... 

Seen it many many times-

 

 

S

[snowking]

In terms of the overall pattern the ECM is vastly different towards the Pacific and polar region compared to its 00hrs output. So I think we need to wait to see exactly which trend is correct however NCEP expect polar air to remain over most of the CONUS so any output that lifts that right into Canada is suspect. Effectively the ECM starts to flatten the pattern out before re-amplifying it again towards day ten.

 

Although the ECM remains cold throughout I'm dubious as to whether it hasn't gone a bit walkabout from T168hrs.

 

As ever sensible advice from Mr. Sussex.

 

I mentioned briefly last night my niggling concern at the modelling of any remaining vortex energy around the Greenland locale (despite the overall movement of the upper vortex to the Siberian sector), and caution is advised because this is just one set of runs amongst a very varied suite of ensemble runs through today, but unfortunately in recent years (for some reason) if something is going to scupper any longer term cold potential it ends up being this.

 

But before we get to any of that, plenty of snowfall opportunities to look forward to over the next 5 days, so not all is lost by any means - especially as we continue to see such a vast array of solutions. It should also be noted that despite the angry look to the vortex at +240, that big -EPO ridge, along with plenty of MLB around elsewhere still, means that cold potential is never far away.

 

SK

Edited January 15, 2015 by snowking

[Cheshire Freeze]

ECM 240 -

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015011512/ECH1-240.GIF?15-

 

Split energy in the atlantic looks to ensure another cold push from the East @ 264...... 

Seen it many many times-

 

 

S

 

With 80% of said energy going N. Useless.

[Long haul to mild]

"Models in try to break down cold early" shocker!

We've seen it time and time again in the past when the cold hangs around longer than expected so maybe it's going to happen again. If a cold spell was being shown at 192, very few would believe it was nailed on so why believe the breakdown?

Haven't had a flake fall yet from this upcoming cold spell and already some have the metaphorical razor blades out! Loads of runs, twists and turns to go yet!

Edited January 15, 2015 by Long haul to mild

[blizzard81]

I hope this thread isn't going to descend into despondency or chaos because of the ECM.

 

You simply can't trust an operational output that goes from this on its 00hrs run:

 

T192hrs:

 

ECH1-192.gif

 

T168hrs on the 12hrs:

 

ECH1-168.gif

 

Although we don't have the 12hr steps theres a chasm between both runs, I think we best wait to see the ECM spreads and ensembles later on.

But Nick, the ECM is not on it's own here. The GFS backs it up. Compare the ECM and GFS at 240hrs. There is a reason why people are banging on about the JMA tonight. It's because the other models have backed off on the longevity of the cold .

[johnholmes]

Clearly the mods have it all on to 'police' every post, but it's a right royal pain scrolling through all the dross to find a knowledgeable/interesting one ABOUT THE MODEL OUTPUT! If I'm posting this in the wrong place, I hold my hands up, but is there any way to build a filter into the forum so we can select (if we want to) a chosen few posters who we know usually talk relevant sense?! And (off topic) if I see 'anomalies' spelled 'anomalys' again, I fear the consequences...

 

quite easy go into your own section and list those who give you a pain, so all you see if there name and no post. But you will at times read their posts as someone else has quoted them but it does help the blood pressure at times!

[Downpour]

JMA - the eye catcher! Exeter!

[winterof79]

My sentiments exactly. The energy over north east canada and Greenland just doesn't want to let go!

It seems to be letting go long enough for many to have a week of snow and cold though.Even if the Azores nudges in snow cover will surpress temps.

Edited January 15, 2015 by winterof79

[ForeverPomeroysnow]

Here's a thought how about we have the knowledgeable posters comment on the charts on a national level for both Islands, remember Ireland next door?? this can be discussed in this thread. Then have these knowledgeable posters give their synopsis in the regional threads that would remove a certain amount of imby and the hogging of the this thread as to whether it will snow on my dog at 4pm on Friday. Feel free to remove, just an idea!!!

[swfc]

"Models in try to break down cold early" shocker!

We've seen it time and time again in the past when the cold hangs around longer than expected so maybe it's going to happen again. If a cold spell was being shown at 192, very few would believe it was nailed on so why believe the breakdown?

Haven't had a flake fall from this cold spell coming up and already some have the metaphorical razor blades out! Loads of runs, twists and turns to go yet!

Tbh i think its just what the 12z have picked up on today on gfs-ecm.To ignore it would be silly"not that anything will varify up to 96 hrs"but its there.Looking at the nhp before today any solid lasting easterly was a long shot imo.Cold snap is on its way but looking at the overall pic looks a long shot to get a lasting easterly in towards the uk.Hopefully later tonight 47-62 synoptics will be on offer