Model Output Discussion - Colder spell ending, what's to follow?

[feb1991blizzard]

6 minutes ago, Sheldon Cooper said:

Signifacnt advances tonight on the Eastern front certainly a good pub run, even the models have been drinking. 

I never drink though

 

Maybe I have a tad, even better on the Eastern front now. 

Now you're talking with that top one, you would get absolutely buried in Kent in the 24 hours after that chart as the low pulls away turning rain to snow!

[Eagle Eye]

1 minute ago, Frosty Winter said:

Sorry but what do you mean by this?

The normal ridge across Scandanavia is flinging lows towards the UK and could be an early sign of something like 2018 because those charts were like this years

A month before

 

[Chesil View]

GFS ensemble no 18 is essentially a repeat of the Great Christmas Blizzard of 1927. Check it out

[Tim Bland]

it’s actually not that unbelievable as an evolution

[syed2878]

I am going to hold back my excitement regarding the upcoming called spell excellent models today how ever I am not falling or buying into it until the Met office is on board.

[Drifter]

1 minute ago, syed2878 said:

I am going to hold back my excitement regarding the upcoming called spell excellent models today how ever I am not falling or buying into it until the Met office is on board.

I’m waiting until WiB is on board. 

[Allseasons-Si]

3 minutes ago, BARRY said:

The country would grind to a halt if that happened 

It does with 1 inch

@Scott Ingham,thanks for your input mate, much appreciated 

it will be interesting to see the eps clusters soon,they didn't really look all that good this morning compared to recent days,yes there was still some N blocking but not much amplification.

 

[Alexis]

The low at the bottom of Greenland on the ECMWF at 240 has slider written all over it.

[SLEETY]

GFS leading the way over ECM,whats going on here It was first in picking this change to colder Weather ironically just after when SM packed it in 

[Jason T]

2 minutes ago, syed2878 said:

I am going to hold back my excitement regarding the upcoming called spell excellent models today how ever I am not falling or buying into it until the Met office is on board.

Why hold back..! This is what the whole model thread is about. If there is away winter can get there its starting to show now, like most have said it's long overdue. Now the fun really starts, early days granted..but seasonal metorogicaly speaking pretty impressive.

 

[Marting]

ECM ensembles showing the 15 day cooling trend nicely, still a big spread though

ECMWF Forecasts

WWW.ECMWF.INT

Martin

[Scott Ingham]

45 minutes ago, feb1991blizzard said:

Is this what is driving the strat warming in GFS 12 FI?  feel that it will fall short of an SSW this time but ripe for the taking around 20th to 30th Jan.

Yes it will have had some bearing on that warming. Ive not had proper time to sit and look at that run but I did notice around 300 hours when the very large eamt event is forecast that we had a big increase in amp. I spotted 3 waves at that stage. Atlantic, Alaskan and Asian that will all have contributed to the warming. Its all linked. Let's put it this way if we get a big enough torque event the dominoe effect on an already weakened vortex by then is going to do our chances of a ssw no harm and not far off amy butlers 7th prediction. I am going for 15th of January however as the rise in +AAM has been delayed i believe by around a week 

Edited December 13, 2020 by Scott Ingham

[Eagle Eye]

Apparently @feb1991blizzard replied can't find it

This year looking like it's balancing on the 21st runs

I'd like to remind everyone that it has snowed as late as March in 2018

So don't be discorouged by this

And remember there are many modes out there that have a brighter future Where we have a Massive Polar Low. 

[Mike Poole]

ECM mean at T240:

Looks good to me, Atlantic ridge into Greenland, vortex banished to other side of the hemisphere.  Just need to get all this into the reliable now. Models just got interesting again with the 12z suite...

[feb1991blizzard]

2 minutes ago, Sheldon Cooper said:

Apparently @feb1991blizzard replied can't find it

This year looking like it's balancing on the 21st runs

I'd like to remind everyone that it has snowed as late as March in 2018

So don't be discorouged by this

 

And remember there are many modes out there that have a brighter future Where we have a Massive Polar Low. 

That's an Atlantic low, not a polar low.

[Scott Ingham]

12 minutes ago, Allseasons-si said:

It does with 1 inch

@Scott Ingham,thanks for your input mate, much appreciated 

it will be interesting to see the eps clusters soon,they didn't really look all that good this morning compared to recent days,yes there was still some N blocking but not much amplification.

 

Two positives. Signs of two and three wave patterns setting up for strat warming and signs of low pressure getting into Europe bank holiday onwards and thanks again for them words I appreciate it 

[chionomaniac]

56 minutes ago, Scott Ingham said:

Don't be too despondent. I'll explain why.

Current State?

We have a northern latitude set up and ongoing weakening of polar winds that are absolutely wipe for northern blocking to take hold due to ongoing weakening of the vortex caused by wave 1 and wave 2 activity the past 4 weeks.

What do we need to take advantage?

Amplification

How do we create amplification?

By creating a rise in angular momentum (AAM)

What can increase angular momentum?

MJO - Tropical convection that moves east into areas of the globe known as the western pacific and central pacific (these are phases 6 7 and 8. Initial forecasts were for a move into 6 and 7 low amp 8 then dieing. Current forecasts show this struggling to get going into 6 which affects its move into 7. Since November this has been under forecast until nearer to time. So no need to worry just yet. Its the NINA we are currently in thats counter acting this. We obviously have cooler waters in the pacific at the minute.

Torque events - This is the current wild card. We have a moderate event an East Asian Mountain Torque (+EAMT) happening right now peaking next Monday or Tuesday as high pressure moves over the Himalayas pushing east into Asia. We also have a forecasted MUCH stronger event due around Christmas time.

What happens if both the convective rain moved east (MJO phases 5 6 and 7) at the same time as the forcing from the torque events? 

We get a rise in AAM (angular momentum) from a base state that isn't that low to start with its just a little above neutral.

What happens if AAM rises?

We get our amplification. Remember the polar field is susceptible right now. Zonal winds are dropping like stones and we have an arctic high waiting for a ridge to come join it from the south to create a winter dance. 

I know the MJO is showing signs of dieing before it gets going but this isn't a certainty the models keep getting it wrong and underestimating it and we have 2 moderate and another strong event almost in the bag.

This year if might not even matter if the MJO runs out or poof and we just have the torque events as the polar atmosphere is so susceptible from the polar high and strat weakening from novembers wave attacks.

Hope this is in enough layman's terms for everyone to understand 

 

Good post Scott. It is one thing understanding how tropical events affect mid latitude wavelengths, but far more difficult to explain in plain English for others to understand. 

[Allseasons-Si]

ECM mean at day ten along side the gefs mean look almost identical,just a tad more ridging on the gefs.

[Scott Ingham]

1 minute ago, chionomaniac said:

Good post Scott. It is one thing understanding how tropical events affect mid latitude wavelengths, but far more difficult to explain in plain English for others to understand. 

Thanks Ed. I appreciate them words! Not bad for someone with Dixlexia haha! I think the condition makes me even more aware of writing for all level of readers 

[Decemberof2010]

1 minute ago, Allseasons-si said:

ECM mean at day ten along side the gefs mean look almost identical,just a tad more ridging on the gefs.

Yes looking like the models are finally on the same page or thereabouts. Let’s hope this can count down now instead of the usual collapse. 
Ive just heard Steve Murr has ordered a new power bank

[chionomaniac]

1 minute ago, Scott Ingham said:

Thanks Ed. I appreciate them words! Not bad for someone with Dixlexia haha! I think the condition makes me even more aware of writing for all level of readers 

You’re welcome. I much prefer plain English than verbose gobbledegook lol. Keep it up

[Allseasons-Si]

Ext EPS are out...

that's a lot better

lol @chionomaniac

Edited December 13, 2020 by Allseasons-si

[northwestsnow]

Eps looking good !!!

[Scott Ingham]

5 minutes ago, Allseasons-si said:

Ext EPS are out...

that's a lot better

Continues the trend to lower heights into Europe. Much much better 

[That ECM]

9 minutes ago, chionomaniac said:

You’re welcome. I much prefer plain English than verbose gobbledegook lol. Keep it up

What are your thoughts? Would be very interested.