Model Output Discussion 1st January 2014-06z onwards.

[Summer Sun]

T240 ends with pressure building

 

 

It also turns milder for the south

 

 

 

At the moment it looks like a cold "snap" rather than "spell"

[Nick L]

Move to correct place mods if you want but just wanted to tell you all:Friday at 7:30 bbc1 - Battered Britan Storms, tides and floods.Monday 7pm ch5 - Worlds wildest weather.

 

"Move to correct place" - this is aimed at everyone by the way, if you have to include this in your post, don't post it! Thanks.

[Cecil Hogmanay Melchett]

T240 ends with pressure building

 

 

It also turns milder for the south

 

 

 

At the moment it looks like a cold "snap" rather than "spell"

Always going to be a snap rather than a spell without help from Greenland..

[East_England_Stormchaser91]

Holy smoke, where the hell has this super cold output come from !!!!    Now you know how quickly these models can flip and how rapid the tide may well turn. 

So after the floods etc, we could be looking down the barrel of some potential ice days in the not so far future. My word...

[Stuie]

Starts to go a little wrong at +240 but them charts are never right lol 

 

 

Totally agree, unless you are in the search of cold then it is nailed on ;-)

[Captain Shortwave]

So this is where I start getting picky with the ECM, great till 192hrs then the low pressure is too far to the west, you want more energy heading into the Med and eastwards to support the high and stop the axis changing.

 

Now folks this is where it gets a bit dicy, you all want snow but the trough disruption isn't going to favour everyone, the best thing all round to give as many people a chance of snow is you get the disruption and this then slides under the high to get the winds round to a more ene flow and very strong this will drive snow showers inland.

 

Overall the ECM is very good but doesn't hit my 10 rating, its about 8.5.

One thing we can say is that the ECM unusually isn't offering insanity by days 9 and 10 compared to usual, the best charts seem to be at the mid range and being tuned up as the time approaches. In the end the ECM whilst we lose the cold 850s, a south easterly flow would keep temperatures in low single figures at best and considering there would be quite a bit of snow on the ground, it would be very cold.

[ukpaul]

As is its wont ECM pushes things too far west in FI. Given the way that we often end up with a blend of GFS and ECM from that range then the thing to look for is the low moving towards the south east at the same time as heights not pushing as far west into Greenland. That way we keep contact with the cold air feeding in.

 

Look for the blend now.

[SE Blizzards]

T240 ends with pressure building

 

 

It also turns milder for the south

 

 

 

At the moment it looks like a cold "snap" rather than "spell"

 

A quick question summer sun...

 

Did you read IF's post saying models in these situations are sometimes over progressive with the breakdown of any cold weather coming from the East?

 

I really would take chart's 144h and beyond with bucket loads, if not lorry loads, of salt (the same salt that's probably going to be needed to grit all the roads next week)

[terrier]

Think anything past t96 at the moment is not worth bothering with in my opinion. If the cold gets entrenched then it will be hard to shift. As Ian alluded too earlier. Just really hope the ECM isn't leading us up the garden path. Last year is still fresh in my mind. Hopefully these charts will still be showing at the weekend. Then I may start to believe. Until then I'm sceptical as I've seen these easterlies go wrong too many times for my liking.

[Summer Sun]

A quick question summer sun...

 

Did you read IF's post saying models in these situations are sometimes over progressive with the breakdown of any cold weather coming from the East?

 

I really would take chart's 144h and beyond with bucket loads, if not lorry loads, of salt (the same salt that's probably going to be needed to grit all the roads next week)

 

This thread has moved on that quickly tonight I haven't had time to read half the posts

[nick sussex]

Overall an exciting evening for coldies and its about time. We're still not quite there yet in terms of the easterly, although with cross model support we should be reasonably confident.

 

In terms of any frontal snow well you have to look at historical precedence in terms of where the trough disruption will occur, as SM mentioned earlier this tends to get corrected further south and west, just as we see a bias with northerly topplers being shunted east the reverse is normally true here.

 

You are in a sense hoping for the best of both worlds, because you want the trough disruption close enough but not too close because then its more marginal and would suggest that the high isn't as strong and robust.

 

There are chances for snow even if you miss the frontal set up, the flow looks strong and this can drive showers well inland and also you may see some disturbances running west in that flow.

Edited January 8, 2014 by nick sussex

[Southender]

Overall an exciting evening for coldies and its about time. We're still not quite there yet in terms of the easterly, although with cross model support we should be reasonably confident.In terms of any frontal snow well you have to look at historical precedence in terms of where the trough disruption will occur, as SM mentioned earlier this tends to get corrected further south and west, just as we see a bias with northerly topplers being shunted east the reverse is normally true here.You are in a sense hoping for the best of both worlds, because you want the trough disruption close enough but not too close because then its more marginal and would suggest that the high isn't as strong and robust.There are chances for snow even if you miss the frontal set up, the flow looks strong and this can drive showers well inland and also you may see some disturbances running west in that flow.

I agree Nick. If we can get a continental drift to last long enough we usually get the odd disturbance paying us a visit from Germany/Holland way.That's not even including the potential for some nice beefy shower trains setting up, especially with a nice big thermal gradient courtesy of the N.Sea hot tub...Or some frontal excitement moving up through the Channel/France.Exciting times at last, but caution advised at this distance as always. Edited January 8, 2014 by Shrimper

[snowice]

Overall an exciting evening for coldies and its about time. We're still not quite there yet in terms of the easterly, although with cross model support we should be reasonably confident.

 

In terms of any frontal snow well you have to look at historical precedence in terms of where the trough disruption will occur, as SM mentioned earlier this tends to get corrected further south and west, just as we see a bias with northerly topplers being shunted east the reverse is normally true here.

 

You are in a sense hoping for the best of both worlds, because you want the trough disruption close enough but not too close because then its more marginal and would suggest that the high isn't as strong and robust.

 

There are chances for snow even if you miss the frontal set up, the flow looks strong and this can drive showers well inland and also you may see some disturbances running west in that flow.

I BET YOU WOULD HAVE GIVEN YOUR RIGHT ARM FOR A CHART LIKE THAT TWO WEEKS BACK NICK?

[Blizzardof82]

Think anything past t96 at the moment is not worth bothering with in my opinion. If the cold gets entrenched then it will be hard to shift. As Ian alluded too earlier. Just really hope the ECM isn't leading us up the garden path. Last year is still fresh in my mind. Hopefully these charts will still be showing at the weekend. Then I may start to believe. Until then I'm sceptical as I've seen these easterlies go wrong too many times for my liking.

That should read I hope the ECM, GFS, JMA, GEM and NAVGEM aren't leading us up the garden path.

[ANYWEATHER]

And the Ecm was really was one of the first models to bring in the cold and gfs came climbing on. At T+240 the gfs wants to carry on partying .keeping the high to the North, whilst the Ecm starts to fall asleep....and sinks the high into Europe. Of course that timeframe is way unreliable but just goes to show that the models can give us grief at times but also a little bit of Comedy too!    Certainly some very interesting times ahead!  

[Purga]

That should read I hope the ECM, GFS, JMA, GEM and NAVGEM aren't leading us up the garden path.

You forgot UKMO

[OldMetMan]

At long last, we seem to be seeing some consensus amongst the models for HP to develop to the NE, with some pretty cold air spreading into the UK. The main question of course is, how long will it last? That's assuming it does actually materialise!

The GFS as you might expect is returning us to mobile conditions quite quickly. On the other hand, the GEM keeps us in the E flow right to the end of its current run. The ECM does rather similarly.

What signals are there at present to suggest a more sustained blocking situation? The 500mb flow has some clues I think:

The much publicised (and misrepresented by the media) polar vortex over the E of N America is heading further E, whilst the upper trough to our immediate W has extended and is disrupting. Further W, much more energy is heading in off the E Pacific, to steadily erode the cold block, and helping to keep the main upper vortex further E. This suggests to me rising heights in the E Atlantic and northwards. Cold air is heading S into Scandinavia. All these factors do, I think, support a blocking pattern.

However, after the remarkable mobility of recent weeks, I don't think it wise to underestimate the reassertion of the jet, such as shown by the GFS, although I think it unlikely we will get storminess on a scale of these last few weeks, if that is what does happen. On the other hand, the overall look of the Atlantic flow at the moment does have a much weaker look in the shorter term. Also, as I posted last time, such a ferocious jet and attendant LPs do not continue indefinitely, even this time of year.

Stratospheric developments, incidentally, are showing mixed signals I think, although a couple of minor warmings have already happened, and a third appears to be underway at the very highest level. Not enough - yet - to disrupt the PV.

So, at the moment, a welcome break from this incessant rain seems likely soon, with a good possibility of cold continental air early next week. The ECM seems to have picked up on the blocking trend most consistently in recent days, so I am inclined to go along with its future runs, as opposed to the GFS.

I can almost see the next headlines: "After the floods, now comes the Big Freeze".

Edited January 8, 2014 by OldMetMan

[nick sussex]

I agree Nick.If we can get a continental drift to last long enough we usually get the odd disturbance paying us a visit from Germany/Holland way.That's nit even including the potential for some nice beefy shower trains setting up, especially with a nice big thermal gradient courtesy of the N.Sea hot tub...

Yes of course in your location a strong east/ene flow is ideal for those heavy snow showers so you must be close to hysteria going off tonights outputs!!!lol

 

I think what I'm trying to do here is to see how we can squeeze the absolute best for the whole UK out of this pattern so my thoughts are with that in mind, now of course if I was still living in Sussex perhaps a bit of IMBYISM would come into the equation.

 

Even then I was  a bit nervous of trough disruption in case the damn thing went too far east! I always tend to go for the safer option that still gives me some snow that I can be sure will be there for a few days.

 

So for me I'd be happy with the gale force ene flow and lots of heavy snow showers, a few troughs thrown in, what we want is to see one of those great satellite pics which show the whole UK under snow.

 

That's where Operation UK Snow comes in! I'll be plotting a route to that and seeing how the models might deliver that, and maybe I might see the odd flake down here although it generally looks fine for mountain snows.

 

PS and of course our friends from Ireland aswell , you've suffered just as much with the crap winter so far.

Edited January 8, 2014 by nick sussex

[Country Boy]

Take a look at the Snow risk chart for 18th January.

If this comes off, it will be full stop U.K.

 

[weather eater]

That should read I hope the ECM, GFS, JMA, GEM and NAVGEM aren't leading us up the garden path.

One would hope not but it’s been known, I'm not so much worried about being lead up the garden path but a little concerned about how big an impact the tweaking of the synoptics over the next few days will have on what we eventually get, (Notice I said tweaking there not Twerking, as that would be deeply unsettling).

[I remember Atlantic 252]

Take a look at the Snow risk chart for 18th January.

If this comes off, it will be full stop U.K.

 

anniversary of last year then, 18th Jan '13 was a snowfest for me

[NorthernRab]

T240 ends with pressure building

 

It also turns milder for the south

 

 

At the moment it looks like a cold "snap" rather than "spell"

 

I would be extremely cautious about looking for the demise of any given cold spell before we know exactly what we're dealing with, the model turnaround in the last 24 hours is testament to that fact. 

 

From experience, I'd say that the models tend to somewhat underestimate the strength of any block from the east, often sweeping a large area of dense cold air out of the way as though it was nothing, not going to happen. 

[nick sussex]

I BET YOU WOULD HAVE GIVEN YOUR RIGHT ARM FOR A CHART LIKE THAT TWO WEEKS BACK NICK?

Yes if I was still living in Sussex, but certainly interesting for those in the highest risk area for that frontal snow. I just did a quick google search, that's an incredible place you live in.It sounds like Game of Thrones should be filmed there. You're not in  a bad location there if its a strong ene flow, that warm Irish Sea might throw up the odd surprise and you never know what might happen with that trough disruption!

[Stuie]

The point of FI must be around the 168 mark. Phasing of the 2 lows which then gets detached and has a Braveheart attempt at subduing the Azores high?

 

168

Phased lows

Low gets detached and heads into oblivion.

[Jason T]

This chart being dotted around 12z ECMWF anomalie (Stating Deal Sealed) I sincerely hope so.