The hunt for cold - Model discussion (late November)

[Snowman.]

6z looks better as the high is further west. Allowing colder uppers to filter into Europe.

If the high is too strong and too far east the cold SE of the high is cut off which has lead to the recent days of weak cold uppers.

Overall just a variation on the Scandi high that looks pretty much set to build, just the orientation is to be discussed.

[throwoff]

Super run that ECM for us in the South East.

Still too far into FI for any excitement, the models did this last year, kept putting things at +10 days and never really materialising

[MR EXTREMES]

nice slider where will heights go now sink or hold firm.

[Met4Cast]

That low is hilarious.. basically a mini hurricane sat out in the North Atlantic 

Never change, GFS.

[Met4Cast]

Despite the hurricane the block is holding it off.

I think we can safely bin the 6z Op, very odd behaviour with the low pressure system.

[weirpig]

3 minutes ago, Daniel Smith said:

Despite the hurricane the block is holding it off.

I think we can safely bin the 6z Op, very odd behaviour with the low pressure system.

Yep  much more northerly attack of the low system  causing a snow to rain event   i expect the parra and 12z will be different. 

[Methuselah]

Not so sure we should 'bin' anything just yet, Daniel, but should wait for the Para? Though not looking so good, for snow anyway, so far this morning...Remember: more runs needed and the building blocks are in place. We might also need a second bite at the cherry...?

[weirpig]

  

 

Quite a difference 6 hours makes    

[MR EXTREMES]

this what we need to happen but cold air subbon and still -4 to -6 uppers perhaps some battle ground situations likely.

but my do it yourself chart would be better.

although as was suggested a little while ago there is certainly a lack of real deep cold to our east still cold and wintry though.

but the wave attacks on the vortex continue i punt last 3rd of this month strato warming and canadian side.

[Met4Cast]

2 minutes ago, Ed Stone said:

Not so sure we should 'bin' anything just yet, Daniel, but should wait for the Para? Though not looking so good, for snow anyway, so far this morning...Remember: more runs needed and the building blocks are in place. We might also need a second bite at the cherry...?

Specifically binning the 6z Op because it's not realistic.. low pressure systems do not behave the way the model has it behaving and they certainly don't go from shortwave to hurricane in the space of 24hrs.. 

[Nick F]

GFS has a tendency to overblow Atlantic lows too much, so not sure I buy the progressiveness of the 06z op in pushing back the block and moving in Atlantic upper trough close to the west. 

06z GFS 500mb heights profile quite markedly lower over the NW Atlantic than the 00z GFS and 00z ECM, with lower heights/deeper troughing meaning the Atlantic more bullish in pushing in from the west. 

I think GFS bias of pushing away blocks to easily at work here!

[BLAST FROM THE PAST]

6 minutes ago, Ed Stone said:

Not so sure we should 'bin' anything just yet, Daniel, but should wait for the Para? Though not looking so good, for snow anyway, so far this morning...Remember: more runs needed and the building blocks are in place. We might also need a second bite at the cherry...?

Agreed, Don’t bin any run yet, I think a tad progressive but waxing and waning/shuffling still to be had.  For me a rock solid Scandi?.....I think it’ll come under pressure..but am relaxed about that, the fact we are getting the setup is enough for now

 

BFTP

 

 

 

Edited December 5, 2018 by BLAST FROM THE PAST

[bluearmy]

1 minute ago, Ed Stone said:

Not so sure we should 'bin' anything just yet, Daniel, but should wait for the Para? Though not looking so good, for snow anyway, so far this morning...Remember: more runs needed and the building blocks are in place. We might also need a second bite at the cherry...?

broadly agree with the sentiment ed but any run that shows a system that deep and defined is going to be skewed - the chance that the system verifies like that being slim 

Gfs and gfsp are certainly going down the phasing across n uk route rather than the second undercut - haven’t checked in detail but are we losing the e euro trough as the low heights are ejected way west by the reverse flow (think early March and last month) which leads to phasing occurring at too high a latitude for us to sustain the deep cold 

[SLEETY]

Amazing how many times I have seen the 06z want to blast through the Atlantic when their is a block in place over Scandinavia.Happens too many times for it not to be some sort of error in the model or something .

[Seasonality]

5 minutes ago, Ed Stone said:

Not so sure we should 'bin' anything just yet, Daniel, but should wait for the Para? Though not looking so good, for snow anyway, so far this morning...Remember: more runs needed and the building blocks are in place. We might also need a second bite at the cherry...?

SCREAMS potential. 

[Summer Sun]

GFS isn't the only one with that low out in the Atlantic ICON 00z also has it

Edited December 5, 2018 by Summer Sun

[MR EXTREMES]

5 minutes ago, weirpig said:

  

 

Quite a difference 6 hours makes    

yes i agree certainly different 

[Methuselah]

1 minute ago, Daniel Smith said:

Specifically binning the 6z Op because it's not realistic.. low pressure systems do not behave the way the model has it behaving and they certainly don't go from shortwave to hurricane in the space of 24hrs.. 

On second thoughts, you're right enough: the 06Z is being far too progressive, with its breakdown...

[SLEETY]

when is the 06z not progressive with a breakdown,should be the question.Straight to the shredder.

[shaky]

I feel sometime next someone is going to get clobbered with a slider snow event!!seems to be building to such an event at the moment!!all the signs are there!!dont think we will see much in the way of snow showers though!could be wrong of course!

[frosty ground]

4 minutes ago, SLEETY said:

when is the 06z not progressive with a breakdown,should be the question.Straight to the shredder.

Yesterday

 

The ensembles clearly show this as an option.

[Iceaxecrampon]

34 minutes ago, Jonathan Rhodri Roberts said:

A classic easterly set up there, with many of us in western areas (away from the north) staying dry, probably much more sunnier too with frosty nights throughout that time period

Its going to be a long winter for us lowland Fylde Coasters!

.....altitude is calling

Iain

[swebby]

7 minutes ago, Daniel Smith said:

Specifically binning the 6z Op because it's not realistic.. low pressure systems do not behave the way the model has it behaving and they certainly don't go from shortwave to hurricane in the space of 24hrs.. 

 

5 minutes ago, bluearmy said:

broadly agree with the sentiment ed but any run that shows a system that deep and defined is going to be skewed - the chance that the system verifies like that being slim ...."

 

5 minutes ago, SLEETY said:

Amazing how many times I have seen the 06z want to blast through the Atlantic when their is a block in place over Scandinavia.Happens too many times for it not to be some sort of error in the model or something .

 

It sure does have that look of a classic dartboard GFS low that inhabits t+ 180 land, so as BA suggests, chance of verifying as shown are slim.

There is clearly some kind of +ve feed back bug that leads to these mid Atlantic monsters appearing in the gfs, probably some kind of unavoidable aberration in the algorithms otherwise they would not work most of the time. I've heard a similar story that Exeter had issues with one of their models having a habit of generating impossibly low (< -100C !) temps in central china (I will add the caveat that this is from a man that knows a man therefore it may have been a model in development stage.)

[feb1991blizzard]

I will go a bit later than GP's 26th Dec for an SSW, the GFS charts are not showing a strong enough warming or wave activity yet, baring in mind that they usually moderate as well, it might take another round to finish the PV off - i will go early - mid January.

 

Caveat being i havent seen EPS 10mb height chart mean or mountain torque charts recently.

Edited December 5, 2018 by feb1991blizzard

[Methuselah]

As the 00Z GEFS ensemble shows, uncertainty really takes-off between the 11th and 13th: