Model output discussion - Jan 3rd onwards

[Battleground Snow]

The para also looks different here at 156, the SSW really ramping up the volatility,  the trop vortex would be under big pressure if those Pacific heights could join the russian ones

Edited January 4, 2021 by Battleground Snow

[Mucka]

GFS has us back in a cold flow by day 9. Unusual to see the output start swinging back toward the better solution after dropping it but UKMO having none of it yet.

GEM 144 only mentioned because it is more supportive of GFS than UKMO and more importantly it is an improvement from the last run

[SMU]

UKMO day 6 

colder again than yesterday -8c still in SE

[Mucka]

21 minutes ago, Steve Murr said:

UKMO day 6 

colder again than yesterday -8c still in SE

But wrong by day 4? 

I guess it has to be favoured over GFS but looking at GFS ensembles there is a huge array of options by day 6/7 with UKMO type solution among a small cluster

GEFS extremes at 144

and mean

 

Not easy to forecast from GFS.

By 168 we will be in a strong Northerly with a deep low pressure and strong winds

OR an Easterly with high pressure over the UK and breeze from the East

OR in milder Westerlies

OR...

Should make for good viewing over the next 24/48hrs

Edited January 4, 2021 by Mucka

[John88B]

41 minutes ago, Battleground Snow said:

The para also looks different here at 156, the SSW really ramping up the volatility,  the trop vortex would be under big pressure if those Pacific heights could join the russian ones

Hi, a question from a complete novice. So is the SSW affecting the models already even though it hasn't actually occurred yet? Or has it occurred? Sorry really confused. Thanks in advance.

[Kasim Awan]

Clear trend from yesterday for Greenland Heights at days 6-8 within the GEFS. Roughly 35% of members phase out the mild air completely as a result. This needs avid watching during this phase of model volatility esp given this is the favoured solution from a telleconnections perspective. 

[Kasim Awan]

ECM this morning takes a big step in the right direction. Azores high needs to retrogress, this HP system has been a real limiting factor in the past few years.

[mulzy]

8 minutes ago, Kasim Awan said:

Clear trend from yesterday for Greenland Heights at days 6-8 within the GEFS. Roughly 35% of members phase out the mild air completely as a result. This needs avid watching during this phase of model volatility esp given this is the favoured solution from a telleconnections perspective. 

Yes, ECM Det also hinting at this at day 8.  One to watch for sure!

[Kasim Awan]

Just now, mulzy said:

Yes, ECM Det also hinting at this at day 8.  One to watch for sure!

Given the ECM op had a more developed version of this pattern a few days ago it is quite credible.

[Kasim Awan]

Wouldn't be surprised if in the next 36 hours or so a total shift in the output occurs.

[DanDorsetUK]

Just let the SSW do its magic and ride it out, pv-forecast on Twitter was saying there will be a huge effect in January from this. You only need to look at the charts he's posting to see how big this it. The downwelling will happen. Highs will break out.

[IDO]

No real changes with the mean this morning on the gefs:

d8>16 mean

The main cluster is a UK high by d10 and variation as to where it lays longitude and latitude? It then gets flattened and the London ens^^^ show the less cold mean rise to about average past d10. The op and control are zonal in FI but the control is flatter whereas the op is a sw>ne flow. Post-d10 on the mean and an Arctic high shows up quickly followed by amplification towards an Alaskan ridge but atm no real sign of a qtr leading to a quick meridional flow with heights forming at high latitude.

ecm at d8-10 does its usual ott ridge forming, so ignoring that as most times it is wrong.

gem is similar to the gfs op take by d10.

All subject to change in these early days. A solid 6-7 days of a good cold spell to enjoy and by then the models would have reached some sort of agreement as to where we go next?

[bluearmy]

I would hang on until the 12z runs from tomorrow to see how much consistency we are seeing by then in the mid range. (Days 7/10)

We may have a more apparent direction of travel by then ........ the ens could well already have a decent handle on that but experience tells us that caution is a good place to be at the moment .....

[dragan]

decent consistency from the last few runs via the gfs.

Basically a marked rise in temps, winds veering south westerly from day 8ish onwards.

I don’t think it would be overly mild due to the strength of wind, but the longer the flow lasts, the milder it would get.

Eastern areas seeing the best of dry weather, although showers or organised spells of rain couldn’t be rules out.

Moray firth area could very well see some of the higher temps with this setup.

[BARRY]

BBC model one scenario, GMB model another. then the GFS ECM UKMO do there own model

 

god it's confusing

[Kasim Awan]

6 minutes ago, bluearmy said:

I would hang on until the 12z runs from tomorrow to see how much consistency we are seeing by then in the mid range. (Days 7/10)

We may have a more apparent direction of travel by then ........ the ens could well already have a decent handle on that but experience tells us that caution is a good place to be at the moment .....

A total split in the GEFS, what is your take on the colder solution? Seems viable & reflects continued blocking tendency.

[PiscesStar]

9 minutes ago, bluearmy said:

I would hang on until the 12z runs from tomorrow to see how much consistency we are seeing by then in the mid range. (Days 7/10)

We may have a more apparent direction of travel by then ........ the ens could well already have a decent handle on that but experience tells us that caution is a good place to be at the moment .....

I suspect the effects of the ssw and other forces haven't been factored in.. Expecting big changes in tonights runs.... 

[bluearmy]

4 minutes ago, Kasim Awan said:

A total split in the GEFS, what is your take on the colder solution? Seems viable & reflects continued blocking tendency.

as the models upgrade, one hopes that they have a better handle on events such as the one currently ongoing. I guess we are about to find out!   It will be interesting to see the 46 tonight to see how that reacts and varies from its previous continuity.  

you will note that I didn’t answer your question

[IDO]

5 minutes ago, Kasim Awan said:

A total split in the GEFS, what is your take on the colder solution? Seems viable & reflects continued blocking tendency.

The ecm mean follows the gefs:

When we lost the trough dropping it was always likely to lead to a flattening of the pattern and trend less cold (d7-d11). How long that lasts is a good question and I am sure that "more runs needed" will be the answer to that conundrum?

[DanDorsetUK]

From my perspective looking at the SSW charts deep cold heading into America and into Europe. High pressure breaking out North and across the pole pushing the cold out in an east direction towards us. East winds setting up with the beast hitting this January.

The Jet stream may fire up but on a low tracking which could down the line benefit the South. I'm quite convinced were in for a very harsh January and well into Febuary as the winds look to stay reversed for some time.

[Kasim Awan]

 

11 minutes ago, bluearmy said:

as the models upgrade, one hopes that they have a better handle on events such as the one currently ongoing. I guess we are about to find out!   It will be interesting to see the 46 tonight to see how that reacts and varies from its previous continuity.  

you will note that I didn’t answer your question

The tropospheric SSW response should become resolved in the next 48-72 hours. This in theory should decrease volatility regarding the outcome. Hopeful attitude but I remember a big shift in January 2013, it's possible this may be similar.

Edited January 4, 2021 by Kasim Awan

[Nick F]

I'd urge caution if anyone is hoping the models will flip back to colder more blocked solutions in the medium range, on the assumption that the SSW occuring today is causing greater model uncertainty. A very strong Pacific jet is trying to flatten out the upper flow pattern downstream across USA and eventually N Atlantic - hence the more zonal runs. We may have to wait until late January for the SSW to have an affect on upper patterns to return us to a colder more blocked pattern, with no QTR. Hopefully my caution is unfounded, but it looks like the Pacific might try to overwhelm our favourable patterns atm.

Edited January 4, 2021 by Nick F

[Severe Siberian icy blast]

3 minutes ago, Kasim Awan said:

 

The tropospheric SSW response should become deliminated in the next 48-72 hours. This in theory should decrease volatility regarding the outcome. Hopeful attitude but I remember a big shift in January 2013, it's possible this may be similar.

I remember this well, chino called it well, quick downwell with a rapid tropospheric response, you would think 7 years on the models have a better handle on these now after the ongoing improving and upgrading of the models most years, 

[Kasim Awan]

8 minutes ago, Nick F said:

I'd urge caution if anyone is hoping the models will flip back to colder more blocked solutions in the medium range, on the assumption that the SSW occuring today is causing greater model uncertainty. A very strong Pacific jet is trying the flatten out the upper flow pattern downstream across USA and eventually N Atlantic - hence the more zonal runs. We may have to wait until late January for the SSW to have an affect on upper patterns to return us to a colder more blocked pattern, with no QTR. Hopefully more caution is unfounded, but it looks like the Pacific is getting to strong.

The Pacific has been an issue for years now. So has the Azores. As I said, the comments I made this morning are given a "hopefull attitude" disclaimer. Based on previous experience, it is possible though is not the favoured outcome.

Edited January 4, 2021 by Kasim Awan

[Howie]

3 minutes ago, Nick F said:

I'd urge caution if anyone is hoping the models will flip back to colder more blocked solutions in the medium range, on the assumption that the SSW occuring today is causing greater model uncertainty. A very strong Pacific jet is trying to flatten out the upper flow pattern downstream across USA and eventually N Atlantic - hence the more zonal runs. We may have to wait until late January for the SSW to have an affect on upper patterns to return us to a colder more blocked pattern, with no QTR. Hopefully my caution is unfounded, but it looks like the Pacific might try to overwhelm our favourable patterns atm.

I thought this is what was helping us!? So confused