Model output discussion - cold spell approaching?

[frosty ground]

Just now, warrenb said:

We shall see.

We shall see what?

If you are saying the pattern will back further west over time and future output will change with it showing what you describe then fair do's but at the moment the Op runs under discussion do not show that, and you have been predicting the Op's to show that for the last 24 hours as they are coming out.

The ensembles show this as a possibility but the act is getting boring of predicting something to happen that never does and never looked like it would,


 

[radiohead]

T240

06Z GFS uppers mostly -6

 

0Z uppers were mostly -8 to -10

 

06Z another cold run in FI but there will be lots of changes before we get there...

 

[warrenb]

Previous experience, if you want locked in cold the initial amplification has to be either over use, or just to the west. Not in mid atlantic. This way, any westward push just opens up the arctic, and any form of jet push will push it into scandi. These amplifications just give a 4 to 5 days of cold before either collapsing or scooting off west or ironically going to far north and allowing the jet to just ride underneath but at to higher latitude for us to tap the cold.

Edited January 12, 2021 by warrenb

[Tim Bland]

Incoming on the Para  

[DEYS(Kent)]

Post 200 on gfs. I know it’s la la land but what a series of charts. Not ideal for us in the SE on face value but synoptically quite astonishing compared to previous years. 

Get the cold in.......

Then wait and see is my motto now..

[Notty]

6 minutes ago, Battleground Snow said:

Pacific ridge storming into the Arctic here like advertised on the mean earlier... Could slice the vortex apart.

 

Yes indeedy

[I remember Atlantic 252]

1 minute ago, Tim Bland said:

Incoming on the Para  

 

for fun of course, but normal for these days, lows track too far south, South of M4 for snow, unlike 90's where north of M4 for snaw

[Battleground Snow]

1 minute ago, Notty said:

Yes indeedy

Let's just sit back and enjoy these runs, even if they don't come off, we may not see these kind of charts for many years again.

It's a great time for model watching. 

 

Edited January 12, 2021 by Battleground Snow

[Singularity]

A 'safer' path from the GFS 06z . Feels more 'familiar' in terms of sequence - spending at least a couple of days looking for showers or disturbances in the flow before the Atlantic systems start to engage with a cold airmass.

Whether that counts for anything is anyone's guess! 

[ICE COLD]

Look at that

[DanDorsetUK]

6 minutes ago, Battleground Snow said:

Pacific ridge storming into the Arctic here like advertised on the mean earlier... Could slice the vortex apart.

 

Mirroring taking place. Quite amazing to see. New warming injection coming shortly too which will only go on to enhance the pattern which will likely push the main lobe South west down the line. I'm 100% convinced we are in for a memorable spell of weather right into Feb.

[goosey007]

5 minutes ago, Tim Bland said:

Incoming on the Para  

now day 8 so inching closer on this model kicking and screaming i will say....

[Tim Bland]

How’s this Warren?

[feb1991blizzard]

2 minutes ago, warrenb said:

Previous experience, if you want locked in cold the initial amplification has to be either over use, or just to the west. Not in mid atlantic. This way, any westward push just opens up the arctic, and any form of jet push will push it into scandi. These amplifications just give a 4 to 5 days of cold before either collapsing or scooting off west.

This is a bit different though, we actually may be able to make do with several bouts of Atlantic ridging up to mid Greenland rather that an 18th Dec 2010 style high here, reason is 1) yes - it wasn't a split SSW but the displacement looks set to last long enough so any troughs exiting the ESB look like they will just pump more air into W Greenland re-inforcing the pattern, recurrent theme this, and as long as nothing cuts off the flow from the NE or NNE, we may actually get a protracted coldspell without a proper cut off high, a Greenland high very far North might actually knacker things up here as the pattern seems so pre-disposed to being Amplified, that one may mean frigid cold spilling too far West and any battlegrounds might occur in the Atlantic, and that would mean a west bases -NAO in turn firing up the Jet and ultimately ending up a +ve NAO.

[sheikhy]

Just now, Tim Bland said:

How’s this Warren?

If the 06z comes to fruition then we really will be stuck in the freezer for a very long time!!

[Froze were the Days]

8 minutes ago, Battleground Snow said:

Let's just sit back and enjoy these runs, even if they don't come off, we may not see these kind of charts for many years again.

We've been 'enjoying' these runs for the last few weeks...here in the snow starved south east it would be good if we started to get some consensus but sadly feel this confusion will be going on for some time yet. ECM 0z this morning looked a dicey run with marginality written all over it.

Edited January 12, 2021 by Froze were the Days

[Notty]

Looks like a pretty unusual Atlantic pressure pattern (I'm no expert)

[Ben Sainsbury]

Check out the WAA on the GFS from the Pacific into the Arctic, which in turn forces the Arctic high towards Greenland. I sense a monster last few frames, just for fun of course!

[Froze were the Days]

1 minute ago, Notty said:

Looks like a pretty unusual Atlantic pressure pattern (I'm no expert)

Now that HAS west based NAO all over it...we don't want to see that!

[NewEra21]

The fact is no matter how a model is currently performing, everything just seems to eventually lead to cold. It's like there's no stopping the pattern, no matter what minor hiccups occur.

[Tim Bland]

Para is a snow fest for everyone...especially the south! 

[warrenb]

4 minutes ago, Froze were the Days said:

Now that HAS west based NAO all over it...we don't want to see that!

Bingo, at last someone has spotted what is happening. The whole pattern backs to far west. The only way this works is if the reversal slackens just at the right time to then push the whole pattern west again. We then need another wave break (second small warming?) to repeat the pattern to keep us in the cold.

Edited January 12, 2021 by warrenb

[I remember Atlantic 252]

4 minutes ago, Tim Bland said:

How’s this Warren?

that very chart at that time, dry -10 here, probably -20 Scotland, for fun of course

[Steady Easterly]

1 hour ago, warrenb said:

Still too dependant on phasing. Also, note how the nice charts are always at around 10 days, 5 days ago we were talking about around the 14th-15th, we are now talking about 20th-21st.

Sorry but that is wrong, ive been following this one closely and its always been around 19th-22nd for the colder air, or nice charts as you put it.

[goosey007]

5 minutes ago, Tim Bland said:

How’s this Warren?

CRAZY CHART!