Model Output Discussion - 8th - 14th January

[Snow Run]

I will have a C please bob...

Q: what C has a 7 day cold spell with maxes of -4c...?

S

Could I have another letter please, Bob? Can't find any ensembles for C's other than Copenhagen. I'm thinking somewhere in Eastern Europe, but hoping for Cromer or Chelmsford.

[SMU]

I think given the Choice most people would take the 18z , with an 'almost' perfect Straddled easterly at 192 then many more snow events out to 384-

Also for those who wonder why its never easy modelling Easterlies as opposed to nice sinuous Westerlies heres you answer-

When we had the mild weather in december-

Xmas day Jet-

http://176.31.229.228/modeles/gfs/archives/gfsnh-2011122018-5-114.png?18

Very easy to model,lots of consistency-

T 192 18z TODAY

http://176.31.229.228/modeles/gfs/runs/gfsnh-2012010718-5-192.png?18

Look at the jet - its been ripped to peices with fragments all over the place across the pole- far from easy to model that-

One final thing- Its been a long journey over the last 3 weeks, from the onset of the drip feed fed down from the stratosphere, to the Aleution high modelling, now onto the scandi high- its all fed along nicely- around the 15th- all be it with minimal acceptance from the operational GFS-

What comes after the POSSIBLE scandi high easterly when the stratosphere ramps up another level of warmth-

The zonal winds could go mega Negative & a 4 wave standing pattern with a tanked negative AO is in the mix, months like Feb 47, 63, Jan 85 & feb 56, Feb 86 all spring to mind-

Its all balanced on the mean zonal flow easing off enough to get the heights in the right place at the second bite!

Remember people the Easterly ensembles tracker-

Warsaw, Berlin, Debilt / amsterdam then London - thats how they Crash-

S

[Cloud 10]

Things still cooking very nicely in the stratosphere as well.

Surely some epic runs amongst the gefs ensembles.

[BLAST FROM THE PAST]

I would just advise people to remember similar set-ups involving the Arctic High from years gone by, and what we should expect is failure of the cold air to reach the UK. Thats the bottom line situation from these synoptics and likely going forward evolution.

That is not to say there would not be another shot at something similar later on, but fully expect this one to go the way of the pear. The PV will not yield at this point.

Previous 3 years have put that to bed, its a very much enhanced chance now Ian.

BFTP

[Jason M]

Its all nonsense after 200 hours anyway, but if we ended up with a pattern as shown at the end of FI, I for one would be saying 'deal' every time

I'd actually be more worried if GFS was showing the perfect synoptics for a cold spell in FI because the odds of the model nailing something like that this far out are tiny. Even if we revert to the 1988/89 retro charts of the last couple of weeks tommorow, its just nice to have some interest.

Overall, i'm pleased with the pub run and the fact that were seeing variations on a theme accross a number of different models. Very interesting that GEM picked it up first though (and not for the first time either).

Jason

[Matty M]

Just for any newbies that dont realise. The chance of an easterly for the UK for 5days or more at point stand at about 10-20%. This is what we are excited about, so please do not go telling your relatives and the likes!

[kold weather]

What comes after the POSSIBLE scandi high easterly when the stratosphere ramps up another level of warmth-

The zonal winds could go mega Negative & a 4 wave standing pattern with a tanked negative AO is in the mix, months like Feb 47, 63, Jan 85 & feb 56, Feb 86 all spring to mind-

Its all balanced on the mean zonal flow easing off enough to get the heights in the right place at the second bite!

Yeah, my gut is the 18z GFS is right and there will be a little too much energy for the first bite of the cake. My gut though is you are getting another several warming events going on, so expect some major northern blocking at some point, probably just outside the model's range at the moment.

There is only one way deep FI is going...though 384hrs is probably a rain-snow event for most

I just wished that low at 240hrs wasn't as large and as strong, W/C Europe back upto 6-9C because of that, sorta defeats the point of the intial cold wave in some ways.

[nick sussex]

My problem is we effectivly still don't have anything that cold till maybe 360hrs out...it might be borderline cold enough for some sleet/snow at 216-240hrs but other then that we are once again controlled by the Atlantic.

However if we use our heads and think that FI does tend to overdo low pressure systems....certainly lots of chances from the 18z run. If only that jet didn't come on so strong.

However the 18z really is NOT that cold...as surprising as that may be to some!

Yes I understand your point but getting a correction of a few hundred miles is nothing in global terms, the only reason the GFS didn't send the thread into meltdown was that overblown low, we know from experience that models aren't good at resolving shortwaves and trough disruption in later timeframes.

Given the winter so far who needs a two day easterly which then gets sunk by the PV, I know we have the other warming which could give another attempt but I think we need to see the block further north and the PV edged further west.

We may well see that tomorrow, certainly the ECM 168hrs holds the most potential at that timeframe, given the changes so far who knows what will happen.

[BLAST FROM THE PAST]

Just for any newbies that dont realise. The chance of an easterly for the UK for 5days or more at point stand at about 10-20%. This is what we are excited about, so please do not go telling your relatives and the likes!

And 5 days ago 0% for weeks and weeks and weeks according to the models?

BFTP

[kold weather]

A VERY different 18z control run, thats for sure, shortwaves flattens the pattern totally out by 180hrs...would probably have to get a northerly from that run to get anything cold.

Also little support for the OP, nearly all runs have the jet flattening out the pattern...not a great set of ensembles out to 216hrs...

[SMU]

Not one decent ensemble LOL- Good old 18z

S

[Matty M]

GFS control run doesnt really work things well.

As usual (i dont follow em!) but the ENS only 2 runs show anything similar to OPERATIONAL

[kold weather]

mind you most the GFS ensembles also shoot the AO back positive, which makes them totally suspect given the constant strat warming events going on at the moment...and makes the ensembles ready for the dustbin!!

[Cheese Rice]

Previous 3 years have put that to bed, its a very much enhanced chance now Ian.

BFTP

Previous 3 years also included failed easterlies.

February 19th 2011 produced just this. The Scandi high failed to advocate cold air west towards the UK. The PV was too strong and all we ended up with was a few cold days.

[Bristawl Si]

Not one decent ensemble LOL- Good old 18z

S

One shouldn't get too disheartened about this - it's the trend that counts.

Go back a few days and there were still next to no hints, other than the positive vibes from GP and the 'Strat Warming' guys - now scenarios are being thrown up in the model runs that many were giving up on seeing this winter (incl. moi!).

Trends, trends, trends - that's what matters at this stage.

[Tom Quintavalle]

For those members who are new and are wondering about the excitement re. todays charts and what kind of evolution synoptically we should be looking for.

The benchmark for a classic easterly has to be Jan 1987. Note the situation a few days before the onset of that spell.

http://www.wetterzentrale.de/pics/archive/ra/1987/Rrea00119870109.gif

Which led to this, a couple of days later.

http://www.wetterzentrale.de/pics/archive/ra/1987/Rrea00119870111.gif

Now todays 18z GFS.

http://www.wetterzentrale.de/pics/Rtavn1921.png

Not a million miles away but with more pressure from a stronger PV.

But a very complex synoptic set-up to achieve, many pieces of the jigsaw need to drop into place.

Regards,

Tom.

[nick sussex]

GFS control run doesnt really work things well.

As usual (i dont follow em!) but the ENS only 2 runs show anything similar to OPERATIONAL

I wouldn't worry about the ensembles, operationals always lead the way with easterlies.

The lower resolution of the ensembles especially when the models pick up a new signal often sees them slow to react. If the operationals stick with this trend tomorrow then we should see more jump across, of course thats a big IF!

[SMU]

Dont worry im not interested in the 18z ensembles- the 18z & 06z are always rubbish at times like this-

Anyway just about to don the flame suit-

Look at these charts- then look at our 144 Charts...

So compare 144 to this & run it- ( below is a TAD more amplified)

http://176.31.229.22...47-1-19-0-0.png

http://176.31.229.22...47-1-20-0-0.png

http://176.31.229.22...47-1-21-0-0.png

http://176.31.229.22...47-1-22-0-0.png

http://176.31.229.22...47-1-23-0-0.png

http://176.31.229.22...47-1-24-0-0.png

http://176.31.229.228/modeles/reana/1947/archivesnh-1947-1-25-0-0.png

S

Edited January 7, 2012 by Steve Murr

[Cal]

Previous 3 years also included failed easterlies.

February 19th 2011 produced just this. The Scandi high failed to advocate cold air west towards the UK. The PV was too strong and all we ended up with was a few cold days.

Can you two keep your little disputes aside?

The models are showing very different synoptics from what they was 4-5 days ago, this creating a decent buzz around, however one or two of the wiser folk know when that train is coming and it ain't at 202, 252 or 300hrs! The whole range of solutions the NWP is going to throw out is ridiculous to the sublime, soo many twists and turns will these minor warmings have, oh and when the big one comes into model focus then Ha , crikey forum meltdown (maybe!).

Looking good over the last day or so, love these battles with a NW/SE jet and a cold continental air over the UK, will it, won't it snow scenario's with regards to low pressure out to the west.

http://176.31.229.228/modeles/gfs/runs/gfsnh-2012010718-0-264.png?18

Let the rollercoaster begin

[Tom Quintavalle]

Have to concur with above, really awful set of ensembles, hardly any support for the Op at all.

For quite a while now, we've had Ops that have on the whole been some of the mildest runs, with some decent ensemble members.

Now the complete opposite. All aboard the MOT roller coaster, get your prozac at the door! :lol:

Regards,

Tom

[Osbourne One-Nil]

I don't know if things are still looking good or not (I've been watching Great Expectations, so perhaps that's a sign?), but we've opened a Model Mood Thread, for general comments about our hopes and fears to do with the models. Hopefully, this thread can therefore remain pretty much model-output related discussion?

If your post can't be found in here, it may be that it's been moved into the new thread, but please do try to post in the right one to start off with.

[Cloud 10]

Not one decent ensemble LOL- Good old 18z

S

Should've gone to spec-savers.

[Bobby]

OP runs on pretty much all the major models show something very interesting at mid-FI mark so maybe their higher resolution OP runs are picking on something up first. Obviously been a big shift in things today.

[Cloud 10]

The parallel gefs control run looks more promising.

Meteociel - Cartes Ensemble GFS (ENS/GEFS)

[bluearmy]

The parallel gefs control run looks more promising.

Meteociel - Cartes Ensemble GFS (ENS/GEFS)

thats the 12z. the parallel is out after midnight.