The hunt for cold - Model discussion (late November)

[Yarmy]

1 minute ago, Tim Bland said:

Nice! And probably locked in for a while...perfect run up to Christmas 

If only. Makes a change to see the jet barrelling through Africa rather than Scotland.

[feb1991blizzard]

1 minute ago, Steve Murr said:

Another consistent churn from the GFS - Sub -4 AO - Also the atlantic loading with high pressure in a stationary wave pattern-

Also whoever was looking for the -40c isotherm earlier-

Is the -40c isotherm a good thing or bad?  -  will obviously be massively beneficial if we get a N'ly or PM airmass right down to these shores but does that lessen the likely hood?, either by a temperature gradient meaning shortwave development cutting off the flow before it gets here or because the vortex will strengthen the colder it is meaning its harder to disrupt?

[ICE COLD]

Only 15 days until we get here . Should be quite a smooth run in ? Yer right . 

[SMU]

2 minutes ago, feb1991blizzard said:

Is the -40c isotherm a good thing or bad?  -  will obviously be massively beneficial if we get a N'ly or PM airmass right down to these shores but does that lessen the likely hood?, either by a temperature gradient meaning shortwave development cutting off the flow before it gets here or because the vortex will strengthen the colder it is meaning its harder to disrupt?

Its probably much of a muchness TBH-

As long as it stays in the continental interior it wont impact us

image if that splodge was over debilt & the winds were swinging easterly -

[Snowman.]

A potential spoiler low already is the one the ECM picked up on this evening between D6 and D7 that has already been discussed. The GFS has also picked up on it but surprisingly doesn't make much of it so the high just builds over the top of it but it is just another piece of the puzzle to watch out for tomorrow.

[Ventnor Viking]

2 minutes ago, Snowman. said:

A potential spoiler low already is the one the ECM picked up on this evening between D6 and D7 that has already been discussed. The GFS has also picked up on it but surprisingly doesn't make much of it so the high just builds over the top of it but it is just another piece of the puzzle to watch out for tomorrow.

Good point. Personally I tend to trust the ECM in these situations. Probably will end up in the middle though. Definitely one to watch tomorrow

[Snowman.]

Just now, Shaftesbury Snow said:

Good point. Personally I tend to trust the ECM in these situations. Probably will end up in the middle though. Definitely one to watch tomorrow

0z should defo be an interesting find tomorrow morning. However if the first chance is missed the next 'wave' of amplification would probably only be a few days later. As long as we keep that Arctic high we stand a chance, with that gone we would start getting real desperate. 

[Rocheydub]

Generally speaking, it's the GFS who over-do Atlantic lows... Definitely one to watch. My interest is piqued this evening again!

[Ventnor Viking]

1 minute ago, Snowman. said:

0z should defo be an interesting find tomorrow morning. However if the first chance is missed the next 'wave' of amplification would probably only be a few days later. As long as we keep that Arctic high we stand a chance, with that gone we would start getting real desperate. 

Absolutely, the arctic high is important. The models aren't losing it and have been consistent with it being there or there abouts. Then there's the potential strat warming which should hopefully help things along nicely. 

[Bruegelian]

I remember reading on the forums one or two times, something along the lines of 'cold spells can & do come out of nowhere'. I think it is true to some extent.

[feb1991blizzard]

Excellent GEFS - loads of backing for the op - cmon - please make me eat my words.

[BlueHedgehog074]

1 hour ago, Mike Poole said:

Not sure this 18z run is going for the best place here at T180, looks like the arctic height rise might just shear the head off the bunny rabbit?

Does looks like it. The High Pressure assassinates the bunny on that GFS run (264 hours).

I like bunny rabbits, but don’t mind that blue and purple one getting torched to death by the ridges!

(Also let’s do keep this thread free from bad behaviour please, as there has been a fair bit of bickering tonight. Thanks!)

Edited November 26, 2018 by DiagonalRedLine
Text bit big

[Snowman.]

Adding to what I said earlier, the control is a sort of middle ground between the two with the low more developed it follows the high stopping the initial height rises like the operational does.

 

However it does manage it eventually but not to the extent of the Op.

 

[SMU]

GFS Ensembles now beginning to build the picture 168-192 then the following polar height anomalies build post that-

ENS are more supportive if still scattered with heights etc however look at the difference in mean 12z V 18z 264

Note the polar field filling up better with HP...

[Snowman.]

6 minutes ago, Steve Murr said:

GFS Ensembles now beginning to build the picture 168-192 then the following polar height anomalies build post that-

ENS are more supportive if still scattered with heights etc however look at the difference in mean 12z V 18z 264

Note the polar field filling up better with HP...

Trend contines all the way to the deep reaches of FI, a much more amplified pattern.

  

[feb1991blizzard]

Plenty of undercutting going on or about to go on in FI GEFS.

[Allseasons-Si]

9 minutes ago, feb1991blizzard said:

Excellent GEFS - loads of backing for the op - cmon - please make me eat my words.

Just come in from work and said W.T.F,wow some good charts/models tonight

yes the mean at 240 has more troughing in the atlantic than the 12z

the latest from cpc 8-14 shows a much bigger arctic high than last evening and the eps at day ten also picking it up now

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

https://www.tropicaltidbits.com/analysis/models/?model=ecmwf-ens&region=nhem&pkg=z500a&runtime=2018111712&fh=264

and finally,has anyone seen an L for low pressure on the charts before!!!

here is ukmo 144 hrs(i have circled it in red)

i have never seen that before

p.s,i see that the arctic rabbit is appearing in the models,i know what happened when that was showing i think last year.

a couple of tweets i find interesting.

 

[Snowman.]

Pressure pattern for north of Scotland and directly east of Iceland.

 

Clear sign for some kind of height rises.

[Purga]

20 minutes ago, feb1991blizzard said:

Excellent GEFS - loads of backing for the op - cmon - please make me eat my words.

Would you like a knife & fork?

Edited November 26, 2018 by Purga

[Kirkcaldy Weather]

Just now, feb1991blizzard said:

Plenty of undercutting going on or about to go on in FI GEFS.

some lovely blocked charts, hopefully the start of a colder trend being picked up.

 

P12 is close to being a jackpot run ( beast from the east part 2?) 

 

 

[Weathizard]

Fool me once shame on you, fool me twice shame on me. The models always spew out charts like this then they pick up spoilers as it gets to a more reliable timeframe. Just playing devils advocate, be very careful with under cuts and cut off heights at that range, very rarely happens smoothly. And I mean VERY rarely.

[Mike Poole]

Anyone else still waiting for the FV3 to make it's move into the blocking territory - it has at T252 looks promising where we go from here:

Edited November 26, 2018 by Mike Poole

[Allseasons-Si]

1 minute ago, Mike Poole said:

Anyone else still for the FV3 to make it's move into the blocking territory - it has at T252 looks promising where we go from here:

 

Not qiut as good as the 12z but the same varience of the theme

10hpa looking a bit toastier though,i see a bit of orange there

[Allseasons-Si]

A couple of frames on at 360,-12 pos -8 in there.

the warming gaining momentum now,com'on warming.

 

[Tim Bland]

3 hours ago, Purga said:

Would you like a knife & fork?

Check the date - top right, shows Sunday’s for me ?