Model output discussion - Closing in on Christmas

[Midlands Ice Age]

1 hour ago, Kirkcaldy Weather said:

Runs lately show the big blocking high to the east to increase in strength over the next few weeks, remember the gfs run I posted few nights ago had 1070 hpa but quite a few runs showing 1060 / 1065 hpa. Gfs +6hr temperature chart for this afternoon  plenty cold enough, associated with the section of PV and also the blocking high mentioned across Siberia / to the east 

 

+100

Found the minimum overnight was -53C in Siberia.

The cold is very extensive now over there, and the cold is forecast to intensify rather than weaken..

The real question is can we get any of that into Europe?

MIA

Edited December 17, 2020 by Mapantz
Removed unnecessary comment

[Geordiesnow]

49 minutes ago, West is Best said:

I think this post nails it.

I'd only add that there's the ever present risk of a return to flat zonality but, if not, then this is likeliest scenario and one we've seen all too often in recent years. Not bad for Scottish ski resorts when the gales abate enough for the lifts to open. Any sustainable block looks very unlikely to me and there is a notable absence of cold pooling in places which once upon a time we could bank as certainties: over Russia into Siberia and Scandinavia, even Eastern Europe. It's just not there at the moment.

I feel like we are Canute before the incoming tide. There's no escaping the fact that climate change has altered our winters.

Don't shoot me. It's not my fault.

Disagree regarding the lack of cold over Siberia, the arctic high has displaced the PV towards there but I do agree the lack of cold pools over Scandinavia, Eastern Europe and western Russia is climate change rearing its ugly head because the Russian high is more stronger these days due to warmer air and we know the Russian high is a winter killer for cold here. 

Anyways, the outlook is fairly simple, get some Atlantic ridge, a northerly of some sorts could occur although of course yet again we will be feeding on scraps in terms of cold air but if the ridge is flatter then forget about any northerly. Also that trigger low which has the potential to bring alot of heavy rain could also faf on like on the ECM run which might scupper a northerly shot. 

[Daniel*]

54 minutes ago, West is Best said:

I think this post nails it.

I'd only add that there's the ever present risk of a return to flat zonality but, if not, then this is likeliest scenario and one we've seen all too often in recent years. Not bad for Scottish ski resorts when the gales abate enough for the lifts to open. Any sustainable block looks very unlikely to me and there is a notable absence of cold pooling in places which once upon a time we could bank as certainties: over Russia into Siberia and Scandinavia, even Eastern Europe. It's just not there at the moment.

I feel like we are Canute before the incoming tide. There's no escaping the fact that climate change has altered our winters.

Don't shoot me. It's not my fault.

Erm there is big cold across much of Russia. 

 

Compare to how much warmer in 2019. It’s not difficult to ensure what you post is correct. 

The earth is also coolest it has been in a long time, all of this year....  

[ITSY]

21 minutes ago, Daniel* said:

Erm there is big cold across much of Russia. 

 

Compare to how much warmer in 2019. It’s not difficult to ensure what you post is correct. 

The earth is also coolest it has been in a long time, all of this year....  

Wow that northern hemisphere report is quite something. Almost 0.8c colder now than last January - wonder where the variation is most pronounced 

[Jason M]

20 minutes ago, Daniel* said:

Erm there is big cold across much of Russia. 

 

Compare to how much warmer in 2019. It’s not difficult to ensure what you post is correct. 

The earth is also coolest it has been in a long time, all of this year....  

Sorry, I usually don't engage with this stuff but Maybe take your own advice here and ensure  that what you post is not misleading. It is fair enough to say the lack of cold air on this occasion is not due to climate change (albeit where we may disagree is that its clearly a partial factor IMO), however its somewhat hypocritical to then use two charts across a 12 month period to try and disprove climate change whilst having a cheeky and unnecessary little dig at another poster. Take two different dates and it would be easy to demonstrate the exact opposite argument to what you are making. I won't do that though because this would also prove absolutely nothing one way or the other.

Most of your posts these days are pretty good and constructive so I simply don't get why you have to add the barb. Lets all play nicely 

[Radiating Dendrite]

3 minutes ago, Jason M said:

Sorry, I usually don't engage with this stuff but Maybe take your own advice here and ensure  that what you post is not misleading. It is fair enough to say the lack of cold air on this occasion is not due to climate change (albeit where we may disagree is that its clearly a partial factor IMO), however its somewhat hypocritical to then use two charts across a 12 month period to try and disprove climate change whilst having a cheeky and unnecessary little dig at another poster. Take two different dates and it would be easy to demonstrate the exact opposite argument to what you are making. I won't do that though because this would also prove absolutely nothing one way or the other.

Most of your posts these days are pretty good and constructive so I simply don't get why you have to add the barb. Lets all play nicely 

I think the comparison was only to show the different state of the Northern Hemisphere this year compared to last (which was a mild winter). I am not sure he was trying to disprove climate change, more the notion that the Northern Hemisphere is not cold, it is, just in the wrong places for us to currently benefit.

[Mr.B]

1 hour ago, mushymanrob said:

Using this method would save a lot of excitement/disappointment caused by the wilder swings of the ops.

It was mentioned above by @swfc that our weather looks like coming from the NNW, and the anomaly charts for several days now suggest a mean upper flow from the Northwestern quadrant. So cool unsettled likely imho.

Speculating, all anomaly suites suggest positive heights to latitudes north of the UK.  If we can get cyclogenesis to stop developing over the Eastern seaboard and subsequent energy injected into the jet stream, then maybe a more substantial Greenland block can develop. Im not "coldie" but imho that chances of a proper cold spell this winter are much higher then usual, ive been feeling this now for several weeks as northern blocking has developed.

You actually raise a really interesting question rob. 
 

I can’t read the anomaly charts yet at all, but could @johnholmes or another one of you learned fellows, cross reference the anomaly charts with the closest GFS/EMC Permutations to illustrate a clearer way forward +8 days. It seems the anomalies are more right than wrong at this time and we have enough data variables to possibly match up a way forward.

Apologies if this has been done before and proved not to work, but I can’t recall seeing it in the past. 
 

TIA

Mr. B

 

[MATTWOLVES 3]

Come on guys,let's not pick on others who are seeing the outcomes in a different light! Anyway that's my impression of me being a mod...I don't think I would last too long in the job..  cold pools in Siberia,cold pools in Canada,Mongolia and probably even in Jamaica...who cares where they are,we need them here and pronto Plenty of cold options on the 6Z ens....Trust me it will probably come all at once.

[Frosty.]

Oh my...it could be a cold crimbo according to the GEFS 6z!..snaw is less certain but a cold crimbo would be a vast improvement on recent pathetic attempts!...fingers crossed gang.,wow, now I’m pretending to be legretter ( netweather legend)....sausage baps and stellas for all,,,sorry legretter! 

..

[Daniel*]

20 minutes ago, Jason M said:

Sorry, I usually don't engage with this stuff but Maybe take your own advice here and ensure  that what you post is not misleading. It is fair enough to say the lack of cold air on this occasion is not due to climate change (albeit where we may disagree is that its clearly a partial factor IMO), however its somewhat hypocritical to then use two charts across a 12 month period to try and disprove climate change whilst having a cheeky and unnecessary little dig at another poster. Take two different dates and it would be easy to demonstrate the exact opposite argument to what you are making. I won't do that though because this would also prove absolutely nothing one way or the other.

Most of your posts these days are pretty good and constructive so I simply don't get why you have to add the barb. Lets all play nicely 

I notice it was quite aggressive so I apologise. And, I wasn’t not at all suggesting that.... just in context of ‘now’ the Northern Hemisphere isn’t particularly warm, there isn’t a large absence of cold air generally you must see things from the macro picture not small micro Europe picture, the Arctic is now much colder as well. NH is nowhere near as warm as it was in December 2019, and that set tone for a record breaking warm winter which followed across Eurasia. 
 

Global sea temps continue dropping so perhaps unsurprisingly we’re seeing a cooling for now more evidence of La Niña...

[mushymanrob]

22 minutes ago, Mr.B said:

You actually raise a really interesting question rob. 
 

I can’t read the anomaly charts yet at all, but could @johnholmes or another one of you learned fellows, cross reference the anomaly charts with the closest GFS/EMC Permutations to illustrate a clearer way forward +8 days. It seems the anomalies are more right than wrong at this time and we have enough data variables to possibly match up a way forward.

Apologies if this has been done before and proved not to work, but I can’t recall seeing it in the past. 
 

TIA

Mr. B

 

I think this is certainly one for @johnholmes, im still learning.. but john did post something earlier up this thread (within the last 24 hours)...

[Battleground Snow]

The MJO is really struggling to gain any amplification and looks like being in cod for a while... A question for the more knowledgeable, does having the MJO in cod for the rest of December lower the chances of blocking in the Northern hemisphere?

 

[Downburst]

10 minutes ago, Battleground Snow said:

The MJO is really struggling to gain any amplification and looks like being in cod for a while... A question for the more knowledgeable, does having the MJO in cod for the rest of December lower the chances of blocking in the Northern hemisphere?

 

I am no expert, and with a weak La Nina added to the mix even less so, but this is what the organisation has to say about how MJO effects UK 

How does the MJO impact UK weather?

When the MJO is in its active phase over Indonesia and the West Pacific, it tends to drive a negative North Atlantic Oscillation (NAO) 2 to 3 weeks later.

A positive NAO index tends to be preceded by phase 3 and 4 of the MJO, which brings milder and wetter weather across the UK.

A negative NAO index tends to be preceded by phase 6 and 7, which influences a ‘blocked’ weather pattern and is often associated with colder and drier weather across the UK.

The timescale of the MJO having an influence on North Atlantic weather regimes is usually 10 to 12 days.

[Battleground Snow]

1 minute ago, Downburst said:

I am no expert, and with a weak La Nina added to the mix even less so, but this is what the organisation has to say about how MJO effects UK 

How does the MJO impact UK weather?

When the MJO is in its active phase over Indonesia and the West Pacific, it tends to drive a negative North Atlantic Oscillation (NAO) 2 to 3 weeks later.

A positive NAO index tends to be preceded by phase 3 and 4 of the MJO, which brings milder and wetter weather across the UK.

A negative NAO index tends to be preceded by phase 6 and 7, which influences a ‘blocked’ weather pattern and is often associated with colder and drier weather across the UK.

The timescale of the MJO having an influence on North Atlantic weather regimes is usually 10 to 12 days.

Thanks for the reply... I am guessing when the MJO is not active, the la Nina imprint should be dominant, but I have seen some posts saying the atmosphere is acting more el Nino like, rather than la Nina. Very confusing

[mushymanrob]

16 minutes ago, Battleground Snow said:

The MJO is really struggling to gain any amplification and looks like being in cod for a while... A question for the more knowledgeable, does having the MJO in cod for the rest of December lower the chances of blocking in the Northern hemisphere?

 

At a guess id say no... Because we have a lot of NH blocking and the precictive anomaly charts from all sources are suggesting a lot of Northern Blocking... thats despite a weak MJO.

[Downburst]

Just now, Battleground Snow said:

Thanks for the reply... I am guessing when the MJO is not active, the la Nina imprint should be dominant, but I have seen some posts saying the atmosphere is acting more el Nino like, rather than la Nina. Very confusing

Hey, the low state (and I'll be assaulted for saying this by some) might be related the current ENSO state for sure. It is confusing , certainly for me and if I might I'd suggest in my own experience I've seen some expert people make wrong calls based on MJO analogues in here over the last 10 plus years I have been here. In any case  NOAA say this: 

3. How does the MJO change during the ENSO cycle? Overall, the MJO tends to be most active during ENSO neutral years, and is often absent during moderate-to-strong El Niño and La Niña events. The MJO activity during late 2007 and early 2008, which occurred during La Niña conditions, is unusual but not unprecedented.

[Frosty.]

There seems too be a colder shot coming according too the ECM 0z ensemble mean..among other output!...I think coldies should be grateful that this cold shot coincides with crimbo..and perhaps there is further cold shots too look forward too beyond that!

Edited December 17, 2020 by Jon Snow

[johnholmes]

1 hour ago, Mr.B said:

You actually raise a really interesting question rob. 
 

I can’t read the anomaly charts yet at all, but could @johnholmes or another one of you learned fellows, cross reference the anomaly charts with the closest GFS/EMC Permutations to illustrate a clearer way forward +8 days. It seems the anomalies are more right than wrong at this time and we have enough data variables to possibly match up a way forward.

Apologies if this has been done before and proved not to work, but I can’t recall seeing it in the past. 
 

TIA

Mr. B

 

Bear with me Mr B, I'll see if the 12Z GFS fits what I posted last evening. You will probably find it if you search back, or if I get time, I'll try and rop it in the model thread asap, failing that then sometime this evening.

[johnholmes]

5 hours ago, johnholmes said:

Last evening I did suggest that if the NOAA 500 mb anomaly showed similar to the last two days then there was a 70-75% probability of meridional being the pattern day 4/5 from now out to day 6 or beyond. This was confirmed by the NOAA chart, see below, and its 8-14 has a not very different view. Not just immediately upwind of the UK but also the far west with the trough-ridge set up. This morning the EC-GFS output is also a similar looking pair of charts. Make of it what you wish. The cold will arrive, how cold, will it snow etc are for the synoptic outputs EC-GFS Met to indicate through this period.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Climate Prediction Center - 6-10 Day 500mb Outlook

WWW.CPC.NCEP.NOAA.GOV

 

 

For Mr B and anyone else interested from this morning.

Looking for the last evening output

 

[johnholmes]

1 minute ago, johnholmes said:

For Mr B and anyone else interested from this morning.

Looking for the last evening output

 

Hope this works, from last evening

Just a view of how to try and link synoptic charts to the 500 mb anomaly charts for a, pssibly' more balanced view of what the models are trying to show?

 

 

charts for wed dec 16 2020 anomaly and synoptic.doc176 kB · 12 downloads

[johnholmes]

Just now, johnholmes said:

Hope this works, from last evening

Just a view of how to try and link synoptic charts to the 500 mb anomaly charts for a, pssibly' more balanced view of what the models are trying to show?

 

 

charts for wed dec 16 2020 anomaly and synoptic.doc176 kB · 12 downloads

nope will try again

 

[johnholmes]

Just now, johnholmes said:

nope will try again

 

seems okay

If you want help pse pm me rather than on the model thread-thanks

charts for wed dec 16 2020 anomaly and synoptic.doc

[Downburst]

7 minutes ago, johnholmes said:

seems okay

If you want help pse pm me rather than on the model thread-thanks

charts for wed dec 16 2020 anomaly and synoptic.doc 176 kB · 2 downloads

Thanks John. You know I recall just after Boxing day 2010, maybe a few days after, not sure. Well you posted these 500mb anomaly charts showing the milder change about to come, most welcome for me at that time due to frozen pipes. As much as that crazy weather left a memory, reading your post that day also is in the memory of that period. Many thanks for all the work you do on here.

[Updated_Weather]

Doesn't seem that much difference so far on ICON 12z

[That ECM]

 

“Snow in places” let’s see from the output which places. let’s see if the latest output is similar to this.