Model output discussion - The run up to Christmas

[northwestsnow]

Just now, bluearmy said:

Further to the chat about where the trough might end up, note that the latest eps run retrogresses the Russian ridge back towards a nw Russian  locale .........that may mean the sceuro trough can’t push further east 

Not sure what to make of that   

[snowbob]

1 minute ago, Scott Ingham said:

Anyone thats viewed my posts the past few weeks will know I don't have an attitude complex. Quite the opposite. The ECM also showed a true Greenland high. How can ensembles show a true Greenland high when they are a mean of some that show one and others that dont? The UKMO woukd have shown a Greenland high at 168 and 192 if it went that far. That would mean the UKMO and ECM have come running to the GFS.

I appreciate you have an opinion but im sorry i cant agree when the trend is heavily weighted against what your saying and saying this wont be a prolonged cold spell after the latest eps????? 

I appreciate opinions but not ones backed up by no evidence

Anyway, you have your opinion i have mine. I have confidence in what i think will happen and not much has gone wrong from what i originally posted at the start of December  

If it proves imcorrect it does its all a big learning curve im just weary of posters on the wind up sending newbies down the wrong path 

Totally agree 

your posts have been great and informative. Thankyou 

my post earlier was deleted so won’t go into it now.

but some great posters are leaving this forum due to stupid   
bait posts 

for what it’s worth I believe that the models are just grasping an unprecedented set of dynamics for an island such as ours.

but that’s just an opinion 

[Met4Cast]

3 minutes ago, Scott Ingham said:

Anyone thats viewed my posts the past few weeks will know I don't have an attitude complex. Quite the opposite. The ECM also showed a true Greenland high. How can ensembles show a true Greenland high when they are a mean of some that show one and others that dont? The UKMO woukd have shown a Greenland high at 168 and 192 if it went that far. That would mean the UKMO and ECM have come running to the GFS.

I appreciate you have an opinion but im sorry i cant agree when the trend is heavily weighted against what your saying and saying this wont be a prolonged cold spell after the latest eps????? 

I appreciate opinions but not ones backed up by no evidence

Anyway, you have your opinion i have mine. I have confidence in what i think will happen and not much has gone wrong from what i originally posted at the start of December  

If it proves imcorrect it does its all a big learning curve im just weary of posters on the wind up sending newbies down the wrong path 

Instead of responding to my post with charts & explanations to back up what you're saying, you instead go on the offensive and try to strawman me instead, very telling. 

I agree, we should be wary of false pprophets, shouldn't we Scott?  18z rolling out now, lets see what happens, shall we?

[BlueHedgehog074]

Just like to apologise for the technical error earlier with some of the posts, including those from Met4Cast. One of the members of our team was trying to move over some posts while they were creating the new Model Output thread. But this resulted in a member’s post appearing above the thread creator’s post with no way to move it back. Unfortunately meant the moderator had to lock that thread and redo the Model thread again. Sorry for the inconvenience this may have caused

[Kasim Awan]

I believe there is a significant distinction between an isolated Greenland high and a ridge extending into Greenland. Regarding onwards opportunity the high option would be slightly more promising for easterlies. Most model output shows an extensive ridge with little low pressure to the south (isolation). Hence, the 240h EC outcome is more conducive to activity associated with the ridging & eventuall loss of Greenland pressure.

Edited December 20, 2020 by Kasim Awan

[bluearmy]

I missed much of the commentary on the 12z ops but it should be noted that at this stage of the modelling ahead of us, the gfs has certainly come out on top on the retrogression of the ridge 

[Scott Ingham]

12 minutes ago, feb1991blizzard said:

Nearly had an or------ when i saw that, yes, i was starting to worry as GFS ops had been less pronounced splits lately until that, if i was hyper critical though, right up top its a massive wide split with a stonking big ridge over the pole, but one of the daughter vortices ends up guess where??  -  yes, the Atlantic!

Yeah that is a worry if it ends up in the Atlantic but plenty of time for it to change. A little further west with this though would stop west based nao and supply some moisture as apart from that the vortex is obliterated!

[swfc]

4 minutes ago, northwestsnow said:

Not sure what to make of that   

Im not but I think it means the low can't move east, the one bringing attempted northerly? 

Edited December 20, 2020 by swfc

[northwestsnow]

1 minute ago, bluearmy said:

I missed much of the commentary on the 12z ops but it should be noted that at this stage of the modelling ahead of us, the gfs has certainly come out on top on the retrogression of the ridge 

Much to my amazement !!

 

[frosty ground]

4 minutes ago, bluearmy said:

Further to the chat about where the trough might end up, note that the latest eps run retrogresses the Russian ridge back towards a nw Russian  locale .........that may mean the sceuro trough can’t push further east 

It could push the low west and bring in south westerlies. Not sure there is much support for this at the moment thou

[ANYWEATHER]

Evening All ...Winter has just started, Winter is Young....

[NewEra21]

2 minutes ago, swfc said:

Im not but I think it means the low can't move east, the one bringing attempted northerly? 

If that turns out to be the case, that Russian high has been our main hindrance so far this winter. 

[Man With Beard]

Here's a post that will get lost quickly, but will probably be the most newsworthy weather event of the week - Up to 3 inches of rain falling within 24 hours in a band from Wales to Suffolk/Norfolk, if the ARPEGE is to be believed. Flooding potential.

...Now back to the chase for a flake

[Scott Ingham]

5 minutes ago, snowbob said:

Totally agree 

your posts have been great and informative. Thankyou 

my post earlier was deleted so won’t go into it now.

but some great posters are leaving this forum due to stupid   
bait posts 

for what it’s worth I believe that the models are just grasping an unprecedented set of dynamics for an island such as ours.

but that’s just an opinion 

Thanks mate ive made my point wont be reacting to bait and well see what develops eh? 

I wont he leaving the forum for anyone its a fantastic place to be to share idead around like minded people 

[Man With Beard]

4 minutes ago, swfc said:

Im not but I think it means the low can't move east bringing attempted northerly? 

Correct.

However, renewed strength in the Russian High could also lead to a link up of heights between N Atlantic and Russia with Scandi = easterly for the UK? Just saying...

[NewEra21]

1 minute ago, ANYWEATHER said:

Evening All ...Winter has just started, Winter is Young....

Perfect chart to illustrate if only we could just get that trough to the east of us, those uppers going into the Atlantic would then be slap bang over top of us!

[Scott Ingham]

7 minutes ago, Met4Cast said:

Instead of responding to my post with charts & explanations to back up what you're saying, you instead go on the offensive and try to strawman me instead, very telling. 

I agree, we should be wary of false pprophets, shouldn't we Scott?  18z rolling out now, lets see what happens, shall we?

Id suggest getting back to the models

[syed2878]

15 minutes ago, Mike Poole said:

So, new thread, where are we right now?  

If there was a 3 phase process we have to go through to get decent snowy cold spell nowadays it is something like this:

1. Get a decent high latitude blocking scenario.  This box is now ticked. Cross model agreement on a ridge towards or into Greenland, or even a Greenland high.  
2. Get the cold air in place.  Warm SSTs to our north and east and lack of really cold air in our bit of the NH overall so far this December are a temporary issue here, but in the heart of winter, this should change quickly.
3. Precipitation.  When it comes, will it be snow, need to leave this to within 2 days, or nowcasting, frankly!  

We now move to phase 2.  

But looking a bit further ahead, what of our prospects of a really special cold spell?  

As I alluded to earlier when discussing the ECM, where is any spoiler weather going to come from upstream?  ECM and GFS at T240:

Anything threatening west/left/upstream of the black squiggle?  No.  A pattern favourable for cold could have some longevity.  But...

A SSW could throw everything in the air, so if we are to have one (and we can’t complain - it is all part of the pattern) it needs to land right, it would be double or quits in my view!  GFS 12z at T384 completely mashes the strat vortex:

What effect will this have on the weather in the trop that affects us a few weeks down the line?  That is phase 4, and we have no idea of the answer as yet!

All the best, Mike

 interesting post there mike regarding the Strat if I remember right last winter we had an SSW and that did mess the pattern up we have good Synoptics how ever if we were to get an SSW would that not miss the current pattern and link the trap and the strat?

[Skullzrulerz]

5 minutes ago, Man With Beard said:

Here's a post that will get lost quickly, but will probably be the most newsworthy weather event of the week - Up to 3 inches of rain falling within 24 hours in a band from Wales to Suffolk/Norfolk, if the ARPEGE is to be believed. Flooding potential.

...Now back to the chase for a flake

How much rain do you think is forecast for Cornwall ?

[sheikhy]

18z out to 84 hours and a carbon copy of 12z so far!!!

[Cheshire Freeze]

11 minutes ago, DiagonalRedLine said:

Just like to apologise for the technical error earlier with some of the posts, including those from Met4Cast. One of the members of our team was trying to move over some posts while they were creating the new Model Output thread. But this resulted in a member’s post appearing above the thread creator’s post with no way to move it back. Unfortunately meant the moderator had to lock that thread and redo the Model thread again. Sorry for the inconvenience this may have caused

Can't get the staff these days eh 

[Mike Poole]

6 minutes ago, syed2878 said:

 interesting post there mike regarding the Strat if I remember right last winter we had an SSW and that did mess the pattern up we have good Synoptics how ever if we were to get an SSW would that not miss the current pattern and link the trap and the strat?

Think it was 18/19 winter we had the SSW that didn’t work?  Last year was just nothing from beginning to end!  I honestly don’t know how a SSW would affect the current pattern.  That’s why i say double or quits, it could cement a cold spell in for weeks, or ruin it - this is because it throws the strat vortex into total chaos.  

Edited December 20, 2020 by Mike Poole

[Kasim Awan]

ICON 18Z strengthens the Russian high a little more. From a longtitudinal perspective, this would send the low further south west.

Being realistic in suggesting more moderated uppers and marginal surface conditions is also a completely possible scenario for the D7-11 range. The strengthening of this pattern described could outweigh any bias which pushes the system further east. Hopefully both factors meet somewhere in the middle as per EC mean.

 

[Ice Day]

Crikey, it's been very tetchy on here today...... you can tell there's a cold spell on the horizon!  I bet the mods live in fear of an emerging BFTE!!!!!

Anyway, another good day's model viewing today.  As has been said ad-nauseum on here, do not get concerned about the uppers 6+ days plus out.  They will change, all that matters at that range is the general direction of travel.  The 12z GEFS look very solid, another cold set both mid and long-term.

[Scott Ingham]

19 minutes ago, bluearmy said:

Further to the chat about where the trough might end up, note that the latest eps run retrogresses the Russian ridge back towards a nw Russian  locale .........that may mean the sceuro trough can’t push further east 

There could be a scenario where a sinking trough leads to the high over Greenland linking with the Russian HP. A scenario i believe the ECM played with 2 or 3 days ago. I personally feel well see a relaxation of the heights after surprise snowfall betweem christmas and new year before another bout of amp leads to another rise in heights between Greenland and Iceland. A griceland ridge