The hunt for cold - Model discussion (late November)

[carinthian]

11 minutes ago, northwestsnow said:

Nice one C..

Trouble is knowing our luck EC will be correct with its flatter Atlantic profile..

 

168 UKMO actually looks really promising the more i look at ..

On the face of it yes but we are denied any upper wind and temp profiles on the chart . Also limited viewing to see pressure pattern further to the east, but better than northing. Due shortly to speak to our experts over here shortly and see what they have in store for their updated model this morning. Could be interesting as they have shown the sinking low scenario for quite a few days now.

C

 

Cheers,

 C

Edited December 13, 2018 by carinthian

[Iceaxecrampon]

06z just out for an interesting Saturday up North at least.

Winter definately here - its a bit brisk out there today.

See you on the tops?  

[matty007]

7 minutes ago, Paul said:

Seriously, if some people are getting 'offended' (maybe we should coin it faux offence, like we have faux cold?) by Matty7's post, you need to perhaps take a break from the computer because he's not said anything offensive there. Someone giving an opinion which isn't a prediction of the next ice age is also not automatically a case of trolling, and those who think it is, and worse still attempt to publicly call it out as that are more of an issue within the thread than a persons opinion that the models may not be especially reliable beyond a certain stage. 

That said though, a general comment on a hunch about the rest of winter is zero to do with the models, and should have gone into the general winter thread as it's not relevant to this one, so can we move it back to the models now please. 

Thanks. 

Will make sure to post in the correct thread. 

[WhiteFox]

11 hours ago, feb1991blizzard said:

I think its this, i haven't counted but there is a list here.

Hard to keep up in here sometimes, but the one that catches my eye is Dec 1981. A cold and snowy December and a cold and snowy January followed and that was with a displacement. Having said that, it was an easterly QBO and occurred earlier in December.

Either way, an SSW throws some variability into the mix and has the potential to completely change an established pattern. If we start with a troposheric vortex that is already a bit weaker than normal, then the impact would, probably, be greater than if you have a strong PV.

Of course, after watching the models for about fifteen years it always seems that a lobe of PV always seems to position itself in just the wrong place! 

Anyway, thanks for the list feb1991blizzard; very informative!

 

[feb1991blizzard]

3 minutes ago, WhiteFox said:

Hard to keep up in here sometimes, but the one that catches my eye is Dec 1981. A cold and snowy December and a cold and snowy January followed and that was with a displacement. Having said that, it was an easterly QBO and occurred earlier in December.

Either way, an SSW throws some variability into the mix and has the potential to completely change an established pattern. If we start with a troposheric vortex that is already a bit weaker than normal, then the impact would, probably, be greater than if you have a strong PV.

Of course, after watching the models for about fifteen years it always seems that a lobe of PV always seems to position itself in just the wrong place! 

Anyway, thanks for the list feb1991blizzard; very informative!

 

Believe it or not, there are very knowledgeable professionals that actually believe the most dramatic impacts are with a strong PV.

[Kentspur]

29 minutes ago, Daniel Smith said:

Those charts have always been confusing to me, too much going on - It's the shaded green part you want to focus on and that's showing zonal winds reversing in the forecast period. 

All but 3 GEFS members going for a full reversal at the end of the month now, the mean solidly below. It'd be rather surprising if a reversal didn't happen now..

I've had a look back at some previous forecasts through the autumn and actually even the shorter range predictions by GFS have proven to be wholly inaccurate.  For instance November as shown here should have seen a dip in zonal winds according to the models forecast in late October. I think I will stick to listening to the experts and viewing the model you've presented here. Thanks Daniel

Edited December 13, 2018 by Kentspur

[Snowman.]

1 minute ago, feb1991blizzard said:

Believe it or not, there are very knowledgeable professionals that actually believe the most dramatic impacts are with a strong PV.

Brick in a washing machine.

[WhiteFox]

9 minutes ago, feb1991blizzard said:

Believe it or not, there are very knowledgeable professionals that actually believe the most dramatic impacts are with a strong PV.

I guess that makes sense. Leads in to another question (doesn't it always?): Does a split have more impact on a strong PV as opposed to a displacement on a weaker PV? 

You can tell I work with data right?

[weirpig]

Still a big difference with The Icon And Arpege regarding snowfall on Saturday   The latter still going for a Midland North event  lasting for the majority of the day

[feb1991blizzard]

10 minutes ago, WhiteFox said:

I guess that makes sense. Leads in to another question (doesn't it always?): Does a split have more impact on a strong PV as opposed to a displacement on a weaker PV? 

You can tell I work with data right?

Not sure but you know the compositing site and the Meteociel re-analysis charts - you can use your data assimilation skills to produce a studym TBH though, i dont think once you see the SSW coming into the mid range that its that difficult to see how it will affect the Northern Hemisphere pattern, on this occasion i do feel we could do with a split afterwards if we are to have a really favourable January, im just waiting though for the next weeks worth of runs.

[Met4Cast]

Low heights almost completely gone from Greenland on the 06z GFS run as high pressure gradually begins to build in the area

[Methuselah]

5 minutes ago, WhiteFox said:

I guess that makes sense. Leads in to another question (doesn't it always?): Does a split have more impact on a strong PV as opposed to a displacement on a weaker PV? 

You can tell I work with data right?

Here's an 'interesting' (well I think so!) observation, from Feb's list of SSWs: the initial onset of cold weather, in the winters of '63, '79, '96 and Dec. 2010, was not preceded by a SSW. (Excuse me if I've got any wrong, as I'm often cross-eyed, first thing!)

So, with this year's positive signals and a SSW - we really ought to be very, very hopeful!

[frosty ground]

With such slack conditions Frost and freezing fog could be a real issue next week

[northwestsnow]

7 minutes ago, Daniel Smith said:

Low heights almost completely gone from Greenland on the 06z GFS run as high pressure gradually begins to build in the area

Thanks Dan im at work so dont have time to watch the run:-)

[booferking]

Great run dissect the pv lope near Greenland opens up big potential as we head towards Christmas..

[Methuselah]

Good to see the persistence of the blocking signal:

[mountain shadow]

head to the Med for a white Christmas and T shirt weather for us!

Edit: Pretty horrendous 6z Ops run to be honest. Low pressure in the Atlantic dominating from start to finish, a couple of brief attempts at ridging blown away.

On 12/12/2018 at 08:48, Catacol said:

 

Edited December 13, 2018 by mountain shadow

[ICE COLD]

4 minutes ago, mountain shadow said:

head to the Med for a white Christmas and T shirt weather for us!

Hardly T shirt weather quit chilly for most

[Methuselah]

Oh well...GFS really flapping, post day 12...

[mountain shadow]

1 minute ago, ICE COLD said:

Hardly T shirt weather quit chilly for most

My comments were intended to be tongue in cheek as GB & Ireland are in a South Westerly draw where as the Med has North Easterlies. Also, the time on your screen grab is 6pm, I would suggest maximums of 13 or 14 degrees in some parts at around 3pm.

[ICE COLD]

1 minute ago, mountain shadow said:

My comments were intended to be tongue in cheek as GB & Ireland are in a South Westerly draw where as the Med has North Easterlies. Also, the time on your screen grab is 6pm, I would suggest maximums of 13 or 14 degrees in some parts at around 3pm.

No that’s max temp up until 6pm 

[MR EXTREMES]

lets have a look at the facts or should i say fax charts lol.

it was around this time last week i noticed most models toyed with the idea of an atlantic ridge getting into the southern tip of greenland.

now if you look at the 144 hr fax your see it just starting to amplify this most likely caused by couple of weeks of wave attacks on the pv.

and few models do see the vortex rather fragmented in and around the north atlantic and also on the eastern side of the states and around the east canadian area.

there two main areas of interest scandi retrogress to greenland with perhaps a surge of heights from the atlantic into greenland or just like the first idea of the surge of heights from around bermuda into greenland.

either way its not a certainty that it will be prolonged at the moment but it most certainly gives a better chance this winter.

in my opinion its very possible when the jigsaw pulls together there could well be a winter to remember.

these are only ideas based on what the models show but must remember we have suffered heartache us snow lovers so its always best to be level headed and except sometimes things don't go to plan, pretty much like my whole 24 years on this planet.

but from a 9 year old till now i've loved the weather especially extremes, although i don't enjoy loss of life. 

but there more favourable patterns at the moment and lets no forget the zonal winds and vortex are not at there greatest, but this does not say it might not fight back.

but its already under attack and an early strong warming event is another BIG bonus.

cant wait for the next 4 or 5 days id expect some cracking charts to emerge.

anyway here's the 144 ukmo 500 mb heights and ideas.

and the 120 fax with the ideas.

 

[Banbury]

16 minutes ago, mountain shadow said:

head to the Med for a white Christmas and T shirt weather for us!

Edit: Pretty horrendous 6z Ops run to be honest. Low pressure in the Atlantic dominating from start to finish, a couple of brief attempts at ridging blown away.

Looks cold Xmas day to me 

[Banbury]

 

Really is JFF at this range but Xmas does look a very festive chilly one 

 

Edited December 13, 2018 by Banbury

[MR EXTREMES]

and this is a monster warming with a double whammy with on going wave activity happening right now.