Model output discussion - Into 2021

[Trom]

Just now, Day_9 said:

Cheers, where can we easily reference verification rates?

Verification stats are for the entire northern hemisphere.   What they won't tell you is how a model copes with the additional variables caused by a SSW event.  There's just not a huge amount of data on it.  For example the last one in 2018 caused the models a lot of problems and it took an number of days to settle down.  It's also worth bearing in mind that the models change overtime in terms of resolution and the base algorithms.  So what I'm saying is you won't gain much from looking at verification stats right now.

[Premiere Neige]

4 minutes ago, Snowman. said:

If only the GFS went further, this is a histroic easterly lining up.

 

The sheer cold in europe would be record breaking one would think.

And maybe here if, as you say, it went further....

[Allseasons-Si]

Erm!!!,...guys,what a mean so far.

[Met4Cast]

I tweeted a few days ago saying it was likely the models (but GFS in particular) would lose the plot as the SSW began to take hold.. I think we've just seen that with the 18z and then some.

What an absolutely insane run! Snow for just about all, the cold across Siberia is something I've never seen before, a direct NE from that would be absolutely crippling & would without doubt beat the classic winters of past. 

A true classic pub run! 

[Allseasons-Si]

1 minute ago, Met4Cast said:

I tweeted a few days ago saying it was likely the models (but GFS in particular) would lose the plot as the SSW began to take hold.. I think we've just seen that with the 18z and then some.

What an absolutely insane run! Snow for just about all, the cold across Siberia is something I've never seen before, a direct NE from that would be absolutely crippling & would without doubt beat the classic winters of past. 

A true classic pub run! 

Now that is a ramp Dan...

 

 

[NorthernRab]

28 minutes ago, Steve Murr said:

look at the Siberian cold pushing SW

-40c over Siberia & -32 over Svalbard that will help the ice!

That's not Svalbard, that's Franz Joseph Land and Novaya Zemlya. 

Not to be pedantic, just that these islands rarely come up in conversation and I feel this is their moment. 

Svalbard is at a tropical -16°C there. 

Edited January 2, 2021 by NorthernRab

[Cloud 10]

https://youtu.be/FM7MFYoylVs

 

[Allseasons-Si]

COME ON!!!,...that's a 2010 chart right there.

Edited January 2, 2021 by Allseasons-si

[bluearmy]

I think gfsp is showing us what a downwelling wave actually looks like ........

[Cheshire Freeze]

Fairly standard major SSW response with the two lobes of vortex- Siberian side heading SE towards the UK-

[Snowman.]

Para about to deliver a screaming northerly..

[Cryosphere.]

8 minutes ago, Allseasons-si said:

Erm!!!,...guys,what a mean so far.

Certainly tightens the hay-bail!! looking good..

[Kasim Awan]

12 minutes ago, ALL ABOARD said:

Huh? 

Low dropping through scandi... 

Jet recurving.. 

Definition of a 'blizzard' 

'a severe snowstorm with high winds' 

 

??? 

 

 

A classic blizzard is a prolonged spell of heavy snow in high winds, not streamers which can produce localized like blizzard conditions. There is a big difference, and I can tell you the chart that you posted would not produce a classic blizzard, localized blizzard like conditions yes. 

Now to get a proper classic blizzard typically a southerly jet component is needed to force moisture into the cold air & produce a strong pressure gradient. A la January 1963, March 2013. The 16th Dec 2010 describes well the set up you noted which would produce temporary blizzard conditions. Let me know if I've made it clear mate

Edited January 2, 2021 by Kasim Awan

[NewEra21]

14 minutes ago, Snowman. said:

If only the GFS went further, this is a histroic easterly lining up.

 

The sheer cold in europe would be record breaking one would think.

Looks like we'll have time for a quick BBQ before it arrives

[Snowman.]

Just now, Kasim Awan said:

A classic blizzard is a prolonged spell of heavy snow in high winds, not streamers which can produce localized like blizzard conditions. There is a big difference, and I can tell you the chart that you posted would not produce a classic blizzard, localized blizzard like conditions yes. 

Now to get a proper classic blizzard typically a southerly jet component is needed to force into the cold air & produce a strong pressure gradient.

A blizzard is loosely defined as roughly 3 hours or longer period of snow where sustained winds exceed 35mph.

[Paul_1978]

1 hour ago, Man With Beard said:

ECM individual ensembles: 

At D10, I would describe 22 out of 51 members as a return to average or above average temperatures. Lots of very cold runs still present.

At D15, I would describe 34 out of 51 as above average temperatures. 20-25 members show a long draw SWly.

If I had to make a forecast, I'd say the cold will stay probably at least 10 more days (and therefore the op run too quick), but mild air likely to win out between D10-D15

Let's see how the SSW affects the models in the next few days, and even more so, what upcoming cold spell will bring - I still believe chances of snow at some point(s) is very good for all.

So despite the imminent SSW the ECM ensembles suggest we’ll have mild weather between 12th and 17th Jan? It doesn’t make sense to me. 

[ALL ABOARD]

 

Wow... 

[Snowman.]

Para clearly decides that the later stages of the run are not for mortal eyes. One can only imagine what it looks like.

Edited January 2, 2021 by Snowman.

[na52]

1 minute ago, Snowman. said:

A blizzard is loosely defined as roughly 3 hours or longer period of snow where sustained winds exceed 35mph.

I think you will find a blizzard is defined as 6 pages in this place in less than 10 minutes

[radiohead]

Looking a bit marginal at 372....erm....

[chionomaniac]

So many chances coming up in the next few weeks. I would be very surprised if the majority of us have not seen a significant snowfall before the end of the month.  Of course, some already have, and 850’s are getting colder.

[Allseasons-Si]

1 minute ago, Paul_1978 said:

So despite the imminent SSW the ECM ensembles suggest we’ll have mild weather between 12th and 17th Jan? It doesn’t make sense to me. 

That is ten+days away,they would change accordingly as we nearer the time,do the ens factor in the SSW because they are lower resolution?

[bluearmy]

2 minutes ago, Snowman. said:

Para clearly decides that the later stages of the run are not for mortal eyes. One can only imagine what it looks like.

The electric has already gone off !  

[NewEra21]

Seems like tonight could be the start of the fun and games with the models now taking on board the SSW. 

[bluearmy]

Just now, Allseasons-si said:

That is ten+days away,they would change accordingly as we nearer the time,do the ens factor in the SSW because they are lower resolution?

Yes they do but they may not make a great job of it. However, the gefs have looked remarkably like the gfs in the upper strat past couple days