Model output discussion - Winter has arrived and the hunt for cold is on

[IDO]

5 minutes ago, frosty ground said:

The Ensembles and the operational have shown Cold air masses moving over the UK capable of producing snow over the last 7 days, so whilst a long deep cold spell is unlikely I wouldn't rule out a cold snap in week two. .

Yes, the GFS op did not have a Pacific Ridge whereas the ensemble mean was to the contrary:

So we are hoping that the GFS 0z op was outside the standard deviation, the 06z may help with that variance? Otherwise if it is a trend setter then we will see the tPV more organised like the 0z run, so cold harder for the UK?

In the short-term, the next six days, rain the main factor, not cold:

Tough to see a negative CET anomaly below the norm this December.

[Dennis]

it seems that the christmas -low will not reach west europe this year with warm air  

[frosty ground]

 

Hmmmm heights building to the north with a low tracking over the UK

Edited December 17, 2019 by frosty ground

[mb018538]

ECM clearly a warm outlier this morning:



With even the lowest ensemble members only down at around -2c, there will be no white Xmas for another year it seems - something from a westerly quadrant most likely.



More encouraging is the potential of some higher pressure near the UK later on:

 

[IDO]

6 minutes ago, frosty ground said:

 

Hmmmm heights building to the north with a low tracking over the UK

...the problem we have is getting consistency with that FI more amplified pattern. We have seen the models give us these false dawns too many times to be anything but cynical that we are heading for a more blocked 5-7 day period again. At the moment the signals are mixed and the 06z run looks like a step back further than even the 0z was.

D12: 

From a wave pattern to more of the winter so far, wedges. Though as we enter mid-winter they may provide a better chance of snow than  the elusive easterlies?

All JFF as the models try to reconcile all the background signals and a brave person that could be confident of the D12 NH profile!

[johnholmes]

37 minutes ago, frosty ground said:

The Ensembles and the operational have shown Cold air masses moving over the UK capable of producing snow over the last 7 days, so whilst a long deep cold spell is unlikely I wouldn't rule out a cold snap in week two. .



6z Run showing a cold airmass

Did the 00z show the same?>

[Snow phall]

How much of an effect are the ozone levels above the Arctic having on the models?

MIA's excellent observations in this thread about surface temps being vastly different from what the satellite temps are showing,may be the thing that is throwing the models off.

 

[frosty ground]

1 minute ago, johnholmes said:

Did the 00z show the same?>

Surely you mean did the 06z yesterday show the same?

 

[frosty ground]

2 minutes ago, johnholmes said:

Did the 00z show the same?>

It was just an example of what the Operational's and Ensembles have been throwing out John, Clearly a cold snap can not be ruled out when it is being shown as an option. 

 

[Dennis]

from the north is should happen then.... or GFS0z NNE

[johnholmes]

12 minutes ago, frosty ground said:

Surely you mean did the 06z yesterday show the same?

 

Both are relevant in my view, the 06z yesterday and the 00z this morning?

Edited December 17, 2019 by johnholmes

[johnholmes]

11 minutes ago, frosty ground said:

It was just an example of what the Operational's and Ensembles have been throwing out John, Clearly a cold snap can not be ruled out when it is being shown as an option. 

 

I understand what you are saying but just do not see it happening-sorry

[ItNeverSnowsInWindsor]

12 hours ago, Tim Bland said:

A white new year for most

 

Another mirage showing up in FI again

[MP-R]

A sudden change from very wet and mild to drier and much colder? I certainly hope so, and some promising signs. I remember the change from Christmas/NY flooding in December 2002 to frozen flooded fields and snow showers in early January 2003. A progression like the below would do nicely!

    

We're half way there here, but those heights over Spain need to shove it as it risks a SWerly flow over the UK. Still too knife edge for my liking but good to see cold appearing to the NE.

 

In the shorter term, I'm just praying for cold enough conditions for decent snow in the Alps next week!

[IDO]

Again the mean and control on the 06z far more amplified in the Pacific and Atlantic corridors:

D10>>>

Of course, the GEFS are from the old GFS model so this could be a good test as to how the new GFS is working as we onboard the new ensemble suite in the New Year and the old one is binned?

[swfc]

Bit of a down tick this morning but any real outcomes regarding cold at such distances in fi are beyond my pay scale.think maybe a back reference to GP posts may be based on more solid ground?Hopefully a cold spell to the end of the year does appear but if not something dry would be welcome.Thought John Holmes comments were worth a listen also.hopefully an upward curve towards something seasonal at least threw the rest of today

[Ali1977]

GEFS mean at day 10 looks good for a block occurring over the UK

 

T360, here’s some of the better blocked ENS members, there are others. Big signal there, not all that cold yet but a good NH setting up on many.

Edited December 17, 2019 by Ali1977

[Don]

23 minutes ago, MP-R said:

A sudden change from very wet and mild to drier and much colder? I certainly hope so, and some promising signs. I remember the change from Christmas/NY flooding in December 2002 to frozen flooded fields and snow showers in early January 2003. A progression like the below would do nicely!

    

 

I don't think we would complain too much with a January 2003 repeat.  London had its largest snowfall since February 1991 I believe.

[Don]

10 hours ago, Westonchris said:

models can and do flip pretty quick , if there sniffing out something ....

That latest chart looks rather ugly!  Hopefully it is 'sniffing' out the wrong signal.

[Ali1977]

Eastern Europe is finally set to head into the Freezer, if we do get a block in a decent place it’ll only take a day or 2 too Tap into the cold.

I just wish the METO would push out a more positive forecast for late Dec, without that I just expect any positive signs to dwindle !! Once bitten and all that.

[ItNeverSnowsInWindsor]

1 minute ago, Ali1977 said:

Eastern Europe is finally set to head into the Freezer, if we do get a block in a decent place it’ll only take a day or 2 too Tap into the cold.

I just wish the METO would push out a more positive forecast for late Dec, without that I just expect any positive signs to dwindle !! Once bitten and all that.

The op being a warm outlier doesn’t fill me with too much confidence!

[MP-R]

24 minutes ago, Don said:

I don't think we would complain too much with a January 2003 repeat.  London had its largest snowfall since February 1991 I believe.

Indeed! Anything to stop the relentless rain. A January 2003 is the kind of thing I'd expect in January - cold spell, followed by Atlantic breakthrough, followed by cold again in the final week. Yes please.

All much too far out though at the moment as FI really does depend on what happens in the Christmas week.

[frosty ground]

1 hour ago, johnholmes said:

I understand what you are saying but just do not see it happening-sorry

No need to apologise for holding a different opinion.

[SMU]

39 minutes ago, Ali1977 said:

Eastern Europe is finally set to head into the Freezer, if we do get a block in a decent place it’ll only take a day or 2 too Tap into the cold.

I just wish the METO would push out a more positive forecast for late Dec, without that I just expect any positive signs to dwindle !! Once bitten and all that.

For the UK to get decent continental cold warsaw is always a good starting point as all things being equal we are usually 2-3 days behind them if it does come this way!

[ArHu3]

Mjo seems to be gaining even some more amplitude today and I think it will increase more and more in the next few days when the models finally figure out where exactly it will emerge