Model Output Discussion - the cold has arrived

[chionomaniac]

Took a break from this afternoons outputs - glad I have returned to a more positive outlook. 
Keeping an eye on that MJO, and the hints again of long term Scandi rises. MJO forecasts are nudging away from IO activity and now are focussed into activity in the western Pacific, and post day 10 Scandi height rises result. This is crucial imo to the next phase of winter. The trop PV is still massively disrupted, the Strat PV is trying to gets its act together, but no matter how hard it strengthens if the stoke is large enough into the Strat PV bike wheel, then it can be brought down. Feb 2009 is a classic example of this. 
 

So medium and long term hope, but definitely not guaranteed. 
 

Edited December 14, 2022 by chionomaniac

[Purga]

MOGREPS definitely trending colder

06z                                                                                     12z

      

[SqueakheartLW]

GFS 12z cold prediction for next week

If anyone thought the GFS Op run on the 12z was cold it has good company with several other members that are equally as cold or even colder at the 2m temp level.

P05, P11, P14 and P23 are the best ones in the bunch, especially P11 which turns very cold once again after the mild blip.

There were several more cold 2m temp runs in the collection but not as consistently cold as the above list of ensemble members.

I would say there's a quite strong signal based on 2m temps that things will be turning colder than average again from around midweek onwards. Could it be possible that a white Christmas is on the way.

How will what happens after the mild blip affect the final annual CET mean for 2022?

Recently we have been trending way below the 1991-2020 December mean CET and up to 13th December we are provisionally at 1.408C (-3.702C below the 1991-2020 December mean). This in itself is impressive considering the year we've had and despite this cold start it is still not cold enough to stop us beating the 2014 CET Annual mean record on either the legacy value 10.948C or the new 10.980C value either.

In order to avoid setting a new record we need to get a December mean of 1.052C with no other corrections upwards in any of the other daily means from 2022 to be absolutely certain to avoid setting a new record based on the lower legacy value and a December of 1.052C would see us set an annual mean of 10.947C which is 0.001C short of 2014 (legacy)

Current December 2022 rolling mean vs requirements for 2014 annual mean (legacy + new), an 11C CET year and 1991-2020 mean

Below is the current data I have for December 2022 vs the above categories.

Things are looking promising currently based on provisional CET data if you are looking to avoid setting an annual CET mean record as for up to the 13th we are currently on track at this stage in December to just avoid setting any new records. However if the model mean 2m temp mins and maxes predictions which are the average between the 00z GFS, 00z GEM and 00z ECM turn out to be correct we are about to shoot back above the requirements and put the course to beat 2014 very much back on track again and even an 11C CET mean year is looking very much back on again unless we can trend much colder again after early next week.

Using the mildest GFS 00z ensemble member P17 by 2m temp mins and maxes

If the mildest GFS 00z ensemble member P17 turns out to be correct. This one averages out at a mean of 6.353C for the entire run based on 2m temp mins and maxes for each day between 14th December and 29th December 2022.

As you can see here if we go mild as predicted around Sunday into Monday time then we generally stay mild or very mild out to the 29th then we are very much dead on course to smash the 2014 mean CET records and the 11C CET one quite easily. We could even undo the cold start to this month and end up very much around the average for December based on 1991-2020 December mean so there's still no guarantee at this stage that December 2022 will end below average but there are currently quite high odds on a significantly below average December 2022.

Using the coldest GFS 00z ensemble member P15 by 2m temp mins and maxes

If the coldest GFS 00z ensemble member P15 turns out to be correct. This one averages out at a mean of 0.559C for the entire run based on 2m temp mins and maxes for each day between 14th December and 29th December 2022.

Using this coldest GFS 00z ensemble member 15 we can see that we stay very much in the hunt to avoid setting a new annual CET mean and if things did head this way then it could go right down to the wire and could all end up hinging on what the 31st December daily mean CET value ended up as.

However P11 on GFS 12z could turn out to be correct and that one looks like an even colder ensemble member than that P15 member from the 00z and that one would make sure we don't set an annual CET mean record and would give us a shot at a possible 0C December or even possibly a slim chance of a sub zero CET December.

[Frostbite80]

18z about to kick off, lets hope the colder trend continues!

 

 

[Allseasons-Si]

31 minutes ago, chionomaniac said:

Took a break from this afternoons outputs - glad I have returned to a more positive outlook. 
Keeping an eye on that MJO, and the hints again of long term Scandi rises. MJO forecasts are nudging away from IO activity into the western Pacific, and post day 10 Scandi height rises result. This is crucial imo to the next phase of winter. The trop PV is still massively disrupted, the Strat PV is trying to gets its act together, but no matter how hard it strengthens if the stoke is large enough into the Strat PV bike wheel, then it can be brought down. Feb 2009 is a classic example of this. 
 

So medium and long term hope, but definitely not guaranteed. 
 

The gefs control caught my eye on that it nearly got there with an atempt at Scandi heights with a westerly movement of the Aleutian high through Russia and then into eastern Europe with an easterly all the way from China to the Balkens

all JFF though but i am enjoying viewing the models non the less.

Edited December 14, 2022 by Allseasons-si
Added chart

[TSNWK]

7 minutes ago, Purga said:

MOGREPS definitely trending colder

06z                                                                                     12z

      

The 12z is yesterdays.. trended milder from 12z yesterday to 06z today… 

[blizzard81]

10 minutes ago, Purga said:

MOGREPS definitely trending colder

06z                                                                                     12z

      

That's yesterday's 12z

[Mark wheeler]

4 minutes ago, TSNWK said:

The 12z is yesterdays.. trended milder from 12z yesterday to 06z today… 

Yes here is today's as posted earlier far more scatter than previous runs .

Edited December 14, 2022 by Mark wheeler

[blizzard81]

34 minutes ago, John88B said:

Would it be true to say our coldest winters come when the pv is over to out north east rather than where it seem to prefer to reside over Canada?

Nah. Never as simple as that. 

[damianslaw]

Echo what I said yesterday, its a very complex set up for next week, and I'm letting the models do there thing, suspect more twists and turns, we are in a highly abnormal base state for December, most abnormal position this time of year since 2010, and like then.. mmm might we about to see another very shortlived mild blip and go cold again... in 2010 there was a 3 day milder blip before it became progressively colder again.

The arctic high is a rarity in December, the PV is pulled all over the place, jetstream amplified... 

 

[Lukesluckybunch]

14 minutes ago, Frostbite80 said:

18z about to kick off, lets hope the colder trend continues!

 

 

Which is the time frame we are looking at around 144-168 for it to turn colder again..with that trough dropping down from the north/northeast

[blizzard81]

For just once can we please have a cold ecm control run that comes to fruition. This would be perfect for Christmas

[Thunder Snow]

Way to much to catch up on here, can anyone give me a quick summary of what's going on with todays output thanks

 

 

 

[TSNWK]

5 minutes ago, Lukesluckybunch said:

Which is the time frame we are looking at around 144-168 for it to turn colder again..with that trough dropping down from the north/northeast

On the 12z around 150.. look for cleaner draw from the north east and the drop swinging south and east a bit more this is what was apparant when flicking between 06z and 12z

[tight isobar]

Now then!!! I’ll elaborate after the last suite 18z.. well within the poke..

[Jake March-Jones]

Fingers crossed the 18z is decent... Any hints yet?

[Djdazzle]

1 minute ago, Jake March-Jones said:

Fingers crossed the 18z is decent... Any hints yet?

A bit soon - still in its early stages of rolling out.

[Allseasons-Si]

2 minutes ago, Jake March-Jones said:

Fingers crossed the 18z is decent... Any hints yet?

Too early to tell yet Jake,the run is only out to 102

[Jake March-Jones]

1 minute ago, Djdazzle said:

A bit soon - still in its early stages of rolling out.

Yeah I just saw it's out to 87hours

 

Just now, Allseasons-si said:

Too early to tell yet Jake,the run is only out to 102

I'm premature...

[TSNWK]

5 minutes ago, Jake March-Jones said:

Fingers crossed the 18z is decent... Any hints yet?

Very early at 108 Maybe the Greenland high is smidge south east and the trough over us look cleaner. To my eyes these are not bad things 

Edited December 14, 2022 by TSNWK

[frosty ground]

looks a pretty notable storm fir western Ireland 

[tight isobar]

Reflecting in supports are driving on the operational... ya can have ya cake and eat it soon .. back ridge... = an MLB for starters..

[1947s coming]

1 hour ago, Allseasons-si said:

I had to view the NH chart and,...WOW ,what a chart

Yep the artic high pushing the cold further south , which is also helping to flatten the euro high . Can a stronger high push for Greenland and possibly link with the artic high . The low to the west could just about slide to . Models definitely finding it difficult and not the usual set up , maybe Friday they might have a better idea . Will the cold air and block prove harder to move than first thought and just look at the pv

Edited December 14, 2022 by 1947s coming

[MATTWOLVES 3]

8 minutes ago, 1947s coming said:

Yep the artic high pushing the cold further south , which is also helping to flatten the euro high . Can a stronger high push for Greenland and possibly link with the artic high . The low to the west could just about slide to . Models definitely finding it difficult and not the usual set up , maybe Friday they might have a better idea 

Jesus I was just about to say we could do with a strong build of heights around the urals to put that Vortex through the shredder...but looking at that chart I'm thinking...what PV! We most definitely have a stretched PV so we could be game on for further Height rises towards the NW quite often.

Edit the chart that Si posted by the way.

Edited December 14, 2022 by MATTWOLVES

[Snowmadsam]

Just REMEMBER its ONE RUN and its the 18z, but I expect there would be many a happy face if this run were true