Model output discussion - another cold spell on the horizon?

[SMU]

10 minutes ago, Scott Ingham said:

Not in this situatiom

Gfs for Greenland heights

Ecm for split energy

I would say based on this and ensemble support the odds are 70/30 on a gfs solution but 30 % is still a percent and could come true

GFS will never be ahead of any euro for a greenland high.

The chances of a GH here are near 5% if not below.

Why? Because the models have to much positive tilt on the jet to develop anything other than a blocking atlantic ridge which may stay in situ long enough like the GEM to bring the cold air south more so than the ECM.

The solution lies probably somewhere in the middle.

It looked great intially with the vortex apparently dropping into Europe however that position is morphing North westwards towards Norway & this means it has to come round the back of a low pressure rather than direct NE > SW like before.

As a result its modified warmer & not as good.

 

Edited January 10, 2021 by Steve Murr

[Man With Beard]

Not sure what to make of the ECM. This morning, no snow midweek, this evening, snow for up to 36 hours on a stalled front. Stick to the ensemble means, perhaps the best plan for now? (although those haven't been the most consistent either)

[Kentspur]

21 minutes ago, Cloud 10 said:

JMA rides into town.

 

Let's not forget that JMA seasonal forecasts has so far been the best model at predicting a dominant Nwly&Nly setup this winter

[Daniel*]

T198 seems the op could have got this....

 

00z

[Man With Beard]

btw ECM ensembles this morning leaned heavily in favour of a Greenland High this morning, biggest risk to cold spell on that set was west based -NAO, not collapsed greenie. What will the next batch come up with?

[MATTWOLVES 3]

21 minutes ago, Tim Bland said:

I think it’s 2 consecutive ECM runs and the latest Para that have set the nerves off, if ECM doesn’t look better in the morning we are on Shakey ground ...

Not so sure...John Hammond as just tweeted to say he thinks it will be an outlier in the pack.. Matt H also thinking its barking up the wrong tree..let's just see. Shaky ground perhaps.. but I'm not detecting an earthquake

[Kasim Awan]

7 minutes ago, Daniel* said:

Not good EPS out to T150 and looking more like OP flatter compare difference with earlier.

> 

 

This is only day 6 (144h) though, the 12z GFS op is similar. I'd say that supports the amplification as the heights are retrogressing south west as is shown on GFS, GEM.

[Djdazzle]

If the EPS are worse as is the Exeter update, surely this is significant when backed up with the ECM op?

[Vikos]

This rigde building up over pacific is another stepstone to a possible PV-Split in the 3rd decade

[Scott Ingham]

2 minutes ago, Steve Murr said:

GFS will never be ahead of any euro for a greenland high.

The chances of a GH here are near 5% if not below.

Why? Because the models have to much positive tilt on the jet to develop anything other than a blocking atlantic ridge which may stay in situ long enough like the GEM to bring the cold air south more so than the ECM.

The solution lies probably somewhere in the middle.

It looked great intially with the vortex apparently dropping into Europe however that position is morphing North westwards towards Norway & this means it has to come round the back of a low pressure rather than direct NE > SW like before.

As a result its modified warmer & not as good.

 

I have to disagree with you on the first part mainly experience and from input shared im such scenarios from our friends in America. 

The envelope though is very large and as others have said id be very surprosed if this am outlier and we see the ecm move over to the GFS scenario

I dont personally see a cut off high shown on the 06z but i do see one further east cut off wothout gaining as much latitide.

But its the fun of model watching well see in due time!

[SMU]

1 minute ago, Man Without Beard said:

btw ECM ensembles this morning leaned heavily in favour of a Greenland High this morning, biggest risk to cold spell on that set was west based -NAO, not collapsed greenie. What will the next batch come up with?

They didnt mate.

There may have been a cluster however dont confuse a ridge & a GH on the anomalies 

00z 216 Mean. No GH

[Scott Ingham]

3 minutes ago, Man Without Beard said:

btw ECM ensembles this morning leaned heavily in favour of a Greenland High this morning, biggest risk to cold spell on that set was west based -NAO, not collapsed greenie. What will the next batch come up with?

Yes. Also gefs

Greenie high is minimum 60% chance with this being an outlier in my opiniom

[carinthian]

Interestingly the latest Met Office fax shows a slowing down of the warm front progress for mid -week. The NE of Britain stays in cold air.  Would not be out of the question to see a wave development along the front with a risk of snow on the colder side. The UKMO model in my view seems show an upgrade , especially 96t-144t with a slower deconstruction of the high and transfer of energy further south and east. This progress then could release some real colder air from the north and east . A lot to be decided this coming few days.

C

 

[SMU]

2 minutes ago, Scott Ingham said:

I have to disagree with you on the first part mainly experience and from input shared im such scenarios from our friends in America. 

The envelope though is very large and as others have said id be very surprosed if this am outlier and we see the ecm move over to the GFS scenario

I dont personally see a cut off high shown on the 06z but i do see one further east cut off wothout gaining as much latitide.

But its the fun of model watching well see in due time!

The American pro mets rarely blend the GFS. Its always EPS & ECM & Occasionally GEM driven.

@nick sussex watched them most of the time. He will 100% say the same thing.

Euro blend > GFS always.

 

Also can you show the GH on EPS as it doesnt exist.

Edited January 10, 2021 by Steve Murr

[Daniel*]

3 minutes ago, Man Without Beard said:

btw ECM ensembles this morning leaned heavily in favour of a Greenland High this morning, biggest risk to cold spell on that set was west based -NAO, not collapsed greenie. What will the next batch come up with?

There’s little interest now but the Atlantic ridge is looking less destined to topple as fast looking at T216. I’m not sure what to make of it, is this a wobble or not, usually you’d say no.

[feb1991blizzard]

1 minute ago, Steve Murr said:

They didnt mate.

There may have been a cluster however dont confuse a ridge & a GH on the anomalies 

00z 216 Mean. No GH

TBF they are unlikely to lie 'HEAVILY' in favour at that range though, genuinely worried right now but wont give up until the GEFS flatliners start disappearing one by one like they normally do!

[Tim Bland]

1 minute ago, MATTWOLVES said:

Not so sure...John Hammond as just tweeted to say he thinks it will be an outlier in the pack.. Matt H also thinking its barking up the wrong tree..let's just see. Shaky ground perhaps.. but I'm not detecting an earthquake

Not saying ECM is right, just think we are on thin ice (excuse the pun) relying on the old GFS to be correct especially as the new (proven superior) is not as good this afternoon.  I personally think the GEM is closest to the mark for the next 10 days as it’s a middle ground. PS John Hammond and Matt Hugo are coldies, so they have rose tinted spectacles...if Darren Bett posted it I would take more notice

[Scott Ingham]

Just now, Steve Murr said:

The American pro mets rarely blend the GFS. Its always EPS & ECM & Occasionally GEM driven.

@nick sussex watched them most of the time. He will 100% say the same thing.

Euro blend > GFS always.

Yes.

In other weather patterns

Not in this pattern

Theu already discounted ecms flatter scenario in yesterdays discussion

[Frostbite1980]

@tight isobar any thoughts? Always love trying to work out your interpretation

[Scott Ingham]

3 minutes ago, Steve Murr said:

The American pro mets rarely blend the GFS. Its always EPS & ECM & Occasionally GEM driven.

@nick sussex watched them most of the time. He will 100% say the same thing.

Euro blend > GFS always.

 

Also can you show the GH on EPS as it doesnt exist.

Depends om defimition.

Your ridge i class as a high of heoghts are high enough

If your talkimg cut off then yes i agree

[Kasim Awan]

7 minutes ago, Scott Ingham said:

Yes. Also gefs

Greenie high is minimum 60% chance with this being an outlier in my opiniom

Strong signal here for higher than average 500mb heights over Greenland the problem is whether these heights are toppled like the ECM 12Z OP or become cut off to prevent this & allow a southerly jet which would sustain the high placement. This represents a split in the ENS - some do some don't. Results in a slightly less conclusive actual Z500mb map. Whether this high becomes isolated imo depends on the strength of the Newfoundland jet & angle of the tilt as a result. I have to say a middle ground scenario seems feasible i.e. limited cutting off - with some potential for a NNE flow, however not possible imo to conclude which option is favoured atm seems highly uncertain because there are arguments for either - i.e. GFS performing better in the Greenland area recently, to ECM favoured for jet energy modelling.

Edited January 10, 2021 by Kasim Awan

[Mapantz]

A few posts moved over to here

Some other posts are getting close to being moved to the other thread too. 

Please stick to model discussion. 

Thanks. 

[SMU]

Just now, Scott Ingham said:

Yes.

In other weather patterns

Not in this pattern

Theu already discounted ecms flatter scenario in yesterdays discussion

You keep saying theres a GH on the means. There isnt.

Theres no GH on the GEFS means either.

So what your posting is totally wrong.

GEFS 12z Mean 192.

No GH.

EPS 00z Mean

No GH

12Z  GEM Means

 

The only model is the GFS operational.

Which means its 99% going to be wrong.

[PolarWarsaw]

The 12z ECM is perfectly within the envelope of what's available to us in the next couple of weeks and should not be dismissed just because it doesn't go on to show a more favourable outcome after an SSW. 

In the near term, perhaps some of those that haven't been lucky enough to see falling snow yet this winter, should take notice and focus attention on this coming week as there does appear to be a chance of some sort of transient snow event midweek/later next weekend. 

In terms of where we go towards the end of January, absolutely every single weather type is on the table. 

Keep your expectations in check. 

[Man With Beard]

4 minutes ago, Steve Murr said:

They didnt mate.

There may have been a cluster however dont confuse a ridge & a GH on the anomalies 

00z 216 Mean. No GH

9 minutes ago, Steve Murr said:

They didnt mate.

There may have been a cluster however dont confuse a ridge & a GH on the anomalies 

00z 216 Mean. No GH

 

Fair enough wrt the mean, but about 1/3 had a N Atlantic high ridging into Greenland, and another 1/3 had a full blown Greenland High. I suspect some deep troughs over Greenland on the other members flattened the mean