Model Output Discussion - 14th Jan 12z Onwards

[Dancerwithwings]

Anybody have a link to the UKMO 850hpa temps, it seems there not available on Meteoceil or aren't they available any where...... full stop ?

[Hotspur62]

Repeat after me...

 

 

Boom.

 

SK

Would be happy for that as it keeps us cold in all probability till 26th and therefore keeps the cold spell and snow chances going forward.All way in FI though which I appreciate. I know ECM looks poor for M4 corridor Southwards initially but wouldn't take much tweaking for whole of UK to see snow in next 7 days. Lets be Positive and see what happens. Christ we have been waiting nearly 2 years for a cold spell after all!!

[Eugene]

Fantastic ECM 12z ensemble mean tonight for all the coldies, it's trending progressively colder with an increasing risk of snow and severe frosts, it's every bit as good as the 0z and last night's 12z, perhaps even better..turning much colder and more wintry from the weekend onwards..reasons to be cheerful, many :-)

 

Yes ECM 12Z Mean at T+144 hrs shows a shallower low like I mentioned earlier and further east over England keeping all but Cornwall/Devon as is to be expected in cold enough air for snowfall, nearer to GFS 12Z at that timeframe than ECM 12Z OP was.

Edited January 14, 2015 by Eugene

[bluearmy]

To add to kriss' post of the T276 eps, the remainder of the run maintains the euro trough and hence the cold. That's the secret. If the euro anomoly remains low, it's difficult for the uk not to be cold.

The vortex doesn't stay split to the end of the run but at that distance, much can change. No strong indication of what will happen over the pole. What does begin to show as a mean feature is a growing Griceland upper ridge as the feature consistent around e Greenland begins to spread somewhat. Looks to me like that ridge becomes cut off as the jet comes through and runs into the euro trough with the Azores anomoly sinking somewhat. given this mornings eps and the gefs growing a low anomoly in nw Europe by the end of week 2 and my money is on this cold lasting a couple of weeks at least.

[Captain Shortwave]

I don't really see the need to look into detail going from around day 5 onward.

Basic principle is that we will see an elongated low move south east somewhere through the UK and eventually into Europe. But the timing, position and end positioning of that low are still very much up for debate.

Whilst the model agree on a small area of heights developing to our north, we still do not know how this will affect the upcoming pattern, mainly as the positioning and the strength of this high could affect how the low disrupts and elongates and hence where will receive snowfall along the occluded front which will come with this low.

Beyond that, I see no route back to a westerly pattern myself, with a deep Euro trough it will require quite an explosive jetstream over the states to flatten the pattern to bring this chance. So it is a case of how the surface pattern will set up.

 

Once the low enters Europe, we will need to look for any developments moving up from the continent given the very unstable airmass, these could appear at very short range and deliver the goods.

January 2013 is a great example. The big snow event on the 18th delivered nothing to the south east, but the models picked up around this time that a shortwave would move north/north west out of France and delivered 4 inches of snow on the coast (I was in Great Yarmouth at the time) and over half a foot inland from an event which didn't even exist on any model output just 72 hours earlier. 

All I can say is keep the faith and don't get too stressed about the specifics, the broader trends are good and I would say there would be a good chance of a significant snow event occurring if we do end up with Euro trough and an east/north easterly flow.

 

Onwards and upwards, we still have the weekend to deal with which may bring some joy to some

Edited January 14, 2015 by Captain shortwave

[polar vortex]

Every reason to think that many locations north, south, east and west will see snowfall and lying snow 

next week, exactly where and how much is obviously a big unknown at this stage but the threat is 

most definitely there.

The runs to me anyway look to firming up on a notable wintry spell of weather to come both in terms

of cold and snow. Fingers crossed for real winter weather fans.

[gottolovethisweather]

Every reason to think that many locations north, south, east and west will see snowfall and lying snow 

next week, exactly where and how much is obviously a big unknown at this stage but the threat is 

most definitely there.

The runs to me anyway look to firming up on a notable wintry spell of weather to come both in terms

of cold and snow. Fingers crossed for real winter weather fans.

 

Bang on.

 

For another summary avoiding the local/regional specifics, I pretty much said the same thing earlier here and I am in fact referring to the broad suite of outputs, not simply the ECM.

 

https://forum.netweather.tv/topic/82281-model-output-discussion-14th-jan-12z-onwards/?p=3118559

 

Folks, I know it's an old adage that often gets quoted but let's get the cold in before worrying about daily details. 

 

If the trend continues to show up over the coming days and the broader global hints coming from the Stratospheric as mentioned by Chiono amongst others, this could be a most intriguing way to see out the second part of January. Hell, there was 32cm lying snow at Aviemore today all of a NW flow off the warm ocean. Be very wary of overhype and overexcitement from members posting up individual charts and operational runs is all I would say (fun to do nonetheless), but there is no getting away from it, as quoted in the media, a cold to very cold spell is arriving shortly. 

Edited January 14, 2015 by gottolovethisweather

[Mucka]

I see Steve has already posted on ECM ensemble mean charts. they do suggest the op deepens the low and mixes out the cold from the SW too much.

 

The op has the low 980 pressure whereas the mean is 1000 suggesting most runs have a much less developed low sliding.

 

 

We can see the same with the 850's where the op is on the mild side.

 

 

As for the usual nonsense of people dictating what should and should not be discussed, all MO is up for discussion in here surely?

How the pattern progresses and how it may be sustained or breakdown is not "hunting for a breakdown", it is just discussing the possible developments of FI as we always do.

It would be different if mildies were purposely trolling but let's please not have witch hunts everytime someone discusses FI just because there is a cold spell.

Just enjoy it and the post the charts and discuss what you want to discuss. 

Differing opinions are fine but that is different to wanting to dictate what people should and should not post within the MO thread.

Let the mods do their job.

That is the first and last thing I will say about, I promise.

Edited January 14, 2015 by Mucka

[Geordiesnow]

I wont be getting cold and snow in the next 48 hours, far from it in fact, wet and windy sums up the next 48 hours here. 

 

I don't understand why I should be getting excited about what someone else 300 miles away is going to experience, to be honest I couldn't give a monkeys what someone high up on a hill in Yorkshire is going to get, good on them if they have some snow but it's not what i'l be experiencing here is it. ?

 

Perhaps the regional thread could be a good place to give an IMBY POV on the models?

 

Do have to say, I think you read far too muc into the ECM, in the later parts of the runs, the 00Z run was showing more of a NW'ly and on the 12Z and its NE'ly! And that what members have to bear in mind regarding any easterly potential, the hints are getting stronger but its by no means a foregone conclusion despite some posts suggesting otherwise. 

 

What does look more likely is we will see some cold weather and a brief Northerly which turns into a slack flabby area of low pressure which may in places produce some snow if there is a trough/front mixed in with the slack area of low pressure, if not then I expect frost and freezing fog to be more of a widespread story with any showers reserved for coastal areas exposed to the wind. However pin pointing any sort of detail like that is impossible. What happens after that is uncertain so I think barring any detail changes the outlook to Sunday looks fairly clear cut. 

[Paul]

18z running now, so good time to ask for some help.

 

It's going to be very busy in here tonight and for the next week or so at least by the looks of it, and at these times this thread can be fun, informative and absolutely buzzing. It can also be frustrating - particularly when people don't keep their posts on topic. 

 

So please, if you're not discussing the models, make your post elsewhere - the model banter/moans and ramps thread is an active thread for random semi-model related stuff and reactions to the output:

https://forum.netweather.tv/topic/81281-model-banter-moans-and-ramps-autumnwinter-201415/

 

The regional threads will also be very busy with local chat, info on any snow and so on:

https://forum.netweather.tv/forum/142-regional-discussions/

 

And with the strong winds during the next 24 hours or so, the severe weather area is the spot for discussing the impacts of that.

https://forum.netweather.tv/topic/82219-atlantic-storm-14th-15th-january/

 

Taking just a few seconds to consider where your post fits best will really help keep this thread running smoothly.

 

Thanks

 

Paul

[snowking]

To add to kriss' post of the T276 eps, the remainder of the run maintains the euro trough and hence the cold. That's the secret. If the euro anomoly remains low, it's difficult for the uk not to be cold.

The vortex doesn't stay split to the end of the run but at that distance, much can change. No strong indication of what will happen over the pole. What does begin to show as a mean feature is a growing Griceland upper ridge as the feature consistent around e Greenland begins to spread somewhat. Looks to me like that ridge becomes cut off as the jet comes through and runs into the euro trough with the Azores anomoly sinking somewhat. given this mornings eps and the gefs growing a low anomoly in nw Europe by the end of week 2 and my money is on this cold lasting a couple of weeks at least.

 

That's certainly my take on it and I imagine by the time we get out to +360 it's just noise from the likely variable clusters by that stage (Nick L may be able to offer some clarity there)

 

Whilst nothing is nailed shorter term in terms of the details, we know the overall theme is cold. As you say the suspicion would be a colder than average for much of the remainder of January, especially when you look at the stratospheric signal for a Wave 1 displacement at a useful angle from the US:

 

 

Visible all the way down:

 

 

It's not an especially strong event but as Ed and Tony (and of course our resident dazzling chart producer Andrej) have been saying, the vortex is very much on it's last legs following Ed's now infamous 1/2 SSW (I would look at patenting Diet SSW), and doesn't need much prodding from either direction to influence its location.

 

The concern I have is the tropospheric modelling further down the line of remaining energy around the Greenland area, which has been notoriously badly modelled in recent years, but there's plenty of water to travel under the bridge before we need to concern ourselves with that. And as Tony has just said to me - the Alaskan ridge on the ECM control tonight would make very light work of any ideas the vortex has of leaving a little exit present around the Greenland locale.

 

All in all plenty to be excited about in the shorter term, whilst the potential in the longer term takes the attention of those more seasoned members with memories of all the worrying and concern of run-to-run nuances for shorter term snow prospects - it's all too much to handle.

 

SK

[Hotspur62]

Another trend the models are showing  is that the Vortex is steadily moving over to Siberia which didn't happen at all last winter if memory serves me right and was a significant reason why the States and Canada had a severe Jan & Feb . Having that go for us along with all the other factors like AH staying out West, Lower heights in Central Europe etc certainly enhances the UK's chances of one getting this cold spell and then keeping it for maybe 10 days+.

[leemondo]

Every reason to think that many locations north, south, east and west will see snowfall and lying snow 

next week, exactly where and how much is obviously a big unknown at this stage but the threat is 

most definitely there.

The runs to me anyway look to firming up on a notable wintry spell of weather to come both in terms

of cold and snow. Fingers crossed for real winter weather fans.

I'm glad, its always a good sign when that happens  

[Catacol]

Sorry not really model related but Helen on the BBC weather broadcast has just said we could be heading for the coldest spell of weather for over 2 years

 

Which of course isnt really saying very much bearing in mind last winter and the first 6 weeks of this...

[winterof79]

EDH1-240.gif

 

wonder where that NH profile is headed ..........................

 

wonder if the extended will continue that evolution ?  it hinted at similar a few runs ago. too crazy to contemplate

Cross polar flow....now where have i seen one of those charts......let me see....yes i remember

 

 

 

 

The starting point had s westerlies and a hideous PV too

Edited January 14, 2015 by winterof79

[claret047]

Good Evening one and all,

This is one of my first postings on this thread as I feel rather reluctant to do so as I am far less experienced of analysis weather synopsis as many others on here and am fearful of making a fool of myself. I do, however read this thread avidly every day and thought that I would pluck up the courage and give a punt on how I believe the situation will develop over the coming days. please be gentle with me!

 

Once the storm of tonight departs we will all be in a colder regime. It is just that it will be colder in the north as it generally is with a north or north westerly flow. with a succession of fronts coming south behind each progressively colder air becomes embedded even in southern counties.

 

If and when, and at this stage it is only tentative, winds develop an easterly component even those of us in the southeast and East Anglia should benefit from showers becoming more wintry in nature until we enjoy snow showers.Presumably this is dependent upon high pressure forming over Iceland/ Scandinavia. Perhaps someone far more knowledgeable confirm as this being the case.

 

On a positive note for Dave (TEITS) whilst out walking this morning I saw a large number of sea gulls fly overhead around about lunchtime. Hopefully it bodes well for Fen and Thames Streamers in the longer term.

 

Kind regards

Dave

[Ali1977]

Sat looking like snow showers possible anywhere in the morning

[SMU]

A little snippet of what I look at in terms of seeing the early trends in the model run.

 

The location of the slider low is highly correlated to the angle of CAA coming off the states around T60.

 

Whatever model viewer you are using to view scroll from 1 image of the 18z ( say T60) then slide across to the T66 which is the 12z-

This is of course the same timeframe.

 

 

Ive annotated where to look & compare with the 12z.

 

At t60 the alignment of the CAA is more pronounced to the South V the 12z, so the expectation on 18z trending is that it will slide further west.

 

best regards

steve

[shaky]

Is it me or is everything further west on the gfs 18z at just 84 hours!

[fergieweather]

Yes ECM 12Z Mean at T+144 hrs shows a shallower low like I mentioned earlier and further east over England keeping all but Cornwall/Devon as is to be expected in cold enough air for snowfall, nearer to GFS 12Z at that timeframe than ECM 12Z OP was.

...but a wide spread in solutions in the EC stamps, including at all stages post-weekend and ditto in EPS clusters further ahead. Low confidence re PPN distribution and phase throughout the sequence, starting with the Mon-Tues developments.

[Ice Day]

Good Evening one and all,

This is one of my first postings on this thread as I feel rather reluctant to do so as I am far less experienced of analysis weather synopsis as many others on here and am fearful of making a fool of myself. I do

 

Good post sir, you should post more often.

 

Anyway, it's the new GFS debut pub run and there's 813 people reading the thread.....what can go wrong!!!

 

Out to 84 and some small changes, but all looking OK to my untrained eye, things a bit further west maybe?

 

Edited January 14, 2015 by Ice Day

[bluearmy]

Another trend the models are showing  is that the Vortex is steadily moving over to Siberia which didn't happen at all last winter if memory serves me right and was a significant reason why the States and Canada had a severe Jan & Feb . Having that go for us along with all the other factors like AH staying out West, Lower heights in Central Europe etc certainly enhances the UK's chances of one getting this cold spell and then keeping it for maybe 10 days+.

It's a different year. I bet the low temps in the states will be making news in 10/14 days time. Could be one of those times when the troughs sit in in Europe and the states at the same time.

[Mucka]

Is it me or is everything further west on the gfs 18z at just 84 hours!

 

No, it is more in line with other output. The 12z was too far East and too flat I reckon given all the other output.

[I remember Atlantic 252]

Is it me or is everything further west on the gfs 18z at just 84 hours!

 

Northerly for Sunday looks cleaner, so better sign already, cold, dry, ready for the low mon/tues

[Snowman.]

Heights are much stronger north which will push everything further south..

 

18z  vs  12z