Model Output Discussion - 14th Jan 12z Onwards

[Backtrack]

We've been here before this winter. Still 7-9 days away. Until it comes within 3-4 days, I won't be too excited. Although the best looking charts since 2010 that's for sure.

[Rocheydub]

The only downsides to these EPIC charts this night are:

A) the daily express will be correct for once

B) there's not much room for upgrades, only downgrades... Unless they stay the same??

Anyway, there will be changes in the mornings runs, hopefully very subtle, and not enough to take this beautiful evolving pattern away from us. Fingers crossed.

[East_England_Stormchaser91]

Something most people haven't realised is the models tend to overdo the uppers, on many occasions deep 850's such as these have been pushed further away from our shores back across europe nearer the time. Sometimes we've expected -10 and got -4 instead

Sometimes they can be accurate though, 11th March 2013 Channel low saw some bone chilling -12c uppers march through England . Its all possible, just need a bit of luck and the right synoptics!!

[SE Blizzards]

ECM 12Z ENS for London look very cold.

 

 

 

 

Op was a mild outlier Days 6 + 7. Interesting...

Edited January 14, 2015 by SE Blizzards

[Daniel*]

You know something is occurring when this happens...

I was gunning I do believe in instinctive powers - for this cold spell since late december/early january while many were writing off the whole month how wrong was you...

outside I have a marching band - I would suggest to alleviate IMBY worries and just see what happens. Not everyone is going to be happy...Ian Brown, springs to mind

We are now seeing a downward propagation of the most recent stratospheric warming event towards the troposphere. I believe that minor SSW IMHO proved to to be the springboard... little off topic!. Apologies. But it pays testament to never ever discount anything - even in the most bleak of circumstances.

[Captain Shortwave]

Yes that and the cross model support increases confidence.

Just saying... 

Interesting that at day 5, the ens have anything from a 1030mb Scandi high to no heights whatsoever to our north. That sliding low is guaranteed to happen, but how this develops is still up for grabs. A lot of runs to go to determine how next week will pan out. Hopefully more forcing to elongate the low and hopefully speed up the onset of the easterly and of course deliver a snow for all* event during the first half of next week.

*Note this applies to all areas under the frontal band, this may not reach everyone.

London ensembles are close to freezing by day at the start of next week. That would be a good description of cold weather considering many other areas will probably be colder.

Edited January 14, 2015 by Captain shortwave

[fatyido]

This forum is on fire tonight, but without trying to dampen everyone's spirits, we have been here many times.

Please don't get too carried away - just yet.

We all know that the charts will change tomorrow slightly, leaving a lot of people almost suicidal.

Fingers well and truly crossed.

[marksp]

well, old GFS 18z looks stunning out to t240, -12 850s a plenty, one things for sure for every one its going to bitterly cold in that flow.

not looked past 240h yet but will do for fun. -11 850s touch base at t216 along way off but we can hope.

 

picture from GFS

 

[Mucka]

ECM 12Z ENS for London look very cold.

 

 

 

 

Op was a mild outlier Days 6 + 7. Interesting...

 

 

I think it was fairly well expected it would be on the mild side after viewing the ensemble mean but what I like more is that they are quite firm on extending the cold out to 26th at least which means they are more solidly behind a prolonged cold spell than GFS ensembles.

[knocker]

Latest fax for Monday

 

[pages]

some cracking ensembles. which would you choose?

number 10 is my favorite gets minus 10s over whole of uk then the Atlantic tries to attack and loses. ridiculous run 

Edited January 14, 2015 by pages

[Mucka]

Interesting that at day 5, the ens have anything from a 1030mb Scandi high to no heights whatsoever to our north. That sliding low is guaranteed to happen, but how this develops is still up for grabs. A lot of runs to go to determine how next week will pan out. Hopefully more forcing to elongate the low and hopefully speed up the onset of the easterly and of course deliver a snow for all* event during the first half of next week.

*Note this applies to all areas under the frontal band, this may not reach everyone.

London ensembles are close to freezing by day at the start of next week. That would be a good description of cold weather considering many other areas will probably be colder.

 

Not for a moment did I say it won't be cold, as I pointed out it will be cold for 5 or 6 days even if more energy goes NE we just won't get the reload from the second ridge.

As for the slider being certain, it isn't. It is high probability but as pointed out several GFS ensemble members don't go for it so how is it guaranteed?

You are making me play devils advocate more than I want to now because I am confident it will happen but not certain because the output isn't 100% behind it and nothing in weather is certain, especially prolonged cold spells hanging on sliders at +T96.

The only thing that is guaranteed is a colder spell of 5 or 6 days which is great but let's not assume the deep prolonged cold spell is nailed on.

Edited January 14, 2015 by Mucka

[LeeCovFox]

I don't suppose anybody is able to tell me what the current model output says for Reykjavik? I'm heading up there next Friday for a long weekend and I'm hoping either for a bit of snow and some clear night skies to have a shot at seeing the aurora. Both would be nice but I appreciate that would need a lot of luck! Anyway, I know it's a long way off in terms of accurately predicting weather, but it would be interesting to know what the models are saying now.

[Smiler1709]

We COULD be on the cusp of something amazing here, models are still trying to firm up on what's coming and there's still scope for upgrades, especially as the weather fronts get closer. A few GEFS have a part of the vortex dropping into scandi only for the Atlantic to attack which doesn't go to plan and the system could easily slip throught France bringing us another reload of easterlys, and with the pv being in scandi the temps would be crazy cold if we developed another easterly.

Obviously I'm only speculating on what might happen but this really could develop into a classic...........or it could go T.I.T.S up, we all get let down and go back into the zonal train lol.

Fingers crossed we all get what we deserve

[geordiekev]

Can't post charts now but 24th Jan 1963 has a version.What is more remarkable is the identical cut off low heights to our s/e that we are forecast and that were present in 47,63 and 87 all severe winter periods.Look on meteoceil on archives.Its uncanny.

Thanks Winter, d/l'd meteo ciel but the French menu has me stumped for the archives but Cheers for looking into the archives and I know the years you mentioned get banded about but the northern hemisphere profiles on show just reek potential for a more sustained period of cold to me. It also shows you don't need the trop or other signals to come on board and personally think that the Azores high migration has hopefully been the biggest game changer. If so perhaps we need to look at equatorial influences on the repositioning of the Azores high in tandem with polar influences.

Edited January 15, 2015 by geordiekev

[Pixel]

I don't suppose anybody is able to tell me what the current model output says for Reykjavik? I'm heading up there next Friday for a long weekend and I'm hoping either for a bit of snow and some clear night skies to have a shot at seeing the aurora. Both would be nice but I appreciate that would need a lot of luck! Anyway, I know it's a long way off in terms of accurately predicting weather, but it would be interesting to know what the models are saying now.

keep and eye on this:

http://en.vedur.is/weather/forecasts/atlantic/#type=temp

[Woollymummy]

This is for Reykjavik next w/e, no idea if it will be right though....

[Mucka]

GFS 00z further East again so more widespread ppn Monday night/Tuesday but not as cold with associated warm sector giving rain/sleet/snow depending on location and probably all 3 for some. I'm just outlining what the run shows not saying that this is what will happen.

 

 

UKMO is better with less of a warm sector and less mixing as it pushes the low through whereas GFS is messier.

 

 

We really don't need that low to hang around,

 

But it does on this run like a bad smell.

 

 

192 It has finally sunk enough to start drawing some colder uppers back in.It is still a cold run but funny how quickly we get spoiled by dream charts as coldies.

 

 

Until the ridge topples back in

 

Edited January 15, 2015 by Mucka

[Cheshire Freeze]

GFS 00z further East again so more widespread ppn Monday night/Tuesday but not as cold with associated warm sector giving rain/sleet/snow depending on location and probably all 3 for some. I'm just outlining what the run shows not saying that this is what will happen.

 

 

UKMO is better with less of a warm sector and less mixing as it pushes the low through whereas GFS is messier.

 

 

We really don't need that low to hang around,

 

Being entirely honest here I think I'd rather take the GFS solution. That UKMO 144 chart doesn't scream longevity at all to me....more a brief E'ly with diluted uppers followed by a mid lat high over the UK. The GFS is more frought with fronts and associated mild sectors but a more successful pressure rise behind and colder weather surely following.

 

TBH looking at the output so far this morning it looks like there's a risk the ridging could topple back across us really quite quickly. The 18z GFS was dreamy because of the vertical advection towards Greenland in the midterm...the 0z doesn't show this and the UKMO wouldn't go that way either.

Edited January 15, 2015 by CreweCold

[Mucka]

Being entirely honest here I think I'd rather take the GFS solution. That UKMO 144 chart doesn't scream longevity at all to me....more a brief E'ly with diluted uppers followed by a mid lat high over the UK. The GFS is more frought with fronts and associated mild sectors but a more successful pressure rise behind and colder weather surely following.

 

Each to their own of course but with UKMO you will get the Atlantic ridge linking up with the Scandi ridge like last nights ECM.

We could do with better amplification behind but at least the UKMO has a second cheeky low further South than the one going over the ridge which might help and the ridge won't collapse as quickly linked with the Scandi ridge IMO.

 

It doesn't really matter yet while there is much change run to run.

Edited January 15, 2015 by Mucka

[Cheshire Freeze]

Each to their own of course but with UKMO you will get the Atlantic ridge linking up with the Scandi ridge like last nights ECM.

 

You'd get a link but how long would that high stay propped up for? Once that UK trough sinks away there's nothing stopping a UK high followed by a return to the Atlantic via the NW. The GFS also follows this route eventually so perhaps we're firming up on a shorter spell than initially hoped?

 

If that is the endgame I'd rather get in as much snowfall early next week as possible....hence the GFS solution would be favoured by me in this respect.

Edited January 15, 2015 by CreweCold

[Thunder Snow]

00z precip charts give nearly 24 hours on snow for most of England and Wales

[Mucka]

00z precip charts give nearly 24 hours on snow for most of England and Wales

 

Look again. But let's not get too hung up on individual runs.

Edited January 15, 2015 by Mucka

[BM4PM]

Id take this mornings outputs, thé cold is still coming.

[Man With Beard]

Although undoubtedly cold from Friday onwards, the GFS and UKMO are a real mess to be honest. Just what shape and size this slider low is going to be is very uncertain. Yes there will be snow, but I can't think anyone could safely call where it's going to be just yet, maybe even for Saturday/Sunday. Areas to the SW may well have a short break from the cold around Monday/Tuesday as a mild sector moves in, but how far this sector gets across the country is another massive uncertainty, and it's not inconceivable that it might get as far NE as Birmingham - or stay down in Cornwall. All in all, I foresee an awful lot of nowcasting tomorrow onwards.