Model Output Discussion - 8th - 14th January

[Frosty.]

There again it could end up mild!!!!

Hmmm there's a cheery thought..not

As things stand, the Ecm 00z is choc full of severe wintry potential which would extend well beyond the T+240 hour cut off point and was a huge upgade from last night, the models generally are hinting more strongly than at any stage so far this winter of a major pattern change although the timing of this change is still fuzzy. After the frosty weekend we will probably have a brief return to more zonal conditions as the jet powers up again in response to the Arctic high displacing colder air further south so there are a lot more positives than negatives to take from today's output so far before the 12z arrives.

[TEITS]

Only just seen the ensembles and my word im going to have a ramp about member No7.

http://176.31.229.228/modeles/gens/run/gens-7-1-240.png?6

So what would conditions be like if that came off. Well the SE in particular would get nailed with max temps around -6C, windchill below -10C and snowfall amounts possibly reaching 20 inches in a few selected locations. Away from the SE many will see snowfall and parts of Wales, W Midlands would experience very low min temps if they remained clear at night.

Sorry but I couldn't resist.

[phil nw.]

Hmmm there's a cheery thought..not

As things stand, the Ecm 00z is choc full of severe wintry potential which would extend well beyond the T+240 hour cut off point and was a huge upgade from last night, the models generally are hinting more strongly than at any stage so far this winter of a major pattern change although the timing of this change is still fuzzy. After the frosty weekend we will probably have a brief return to more zonal conditions as the jet powers up again in response to the Arctic high displacing colder air further south so there are a lot more positives than negatives to take from today's output so far before the 12z arrives.

Yes it`s been an overnight trend back to cold Frosty.

It`s worth monitoring the current daily UKMO charts for the subtle differences,ie where the energy goes and the resistance or otherwise of the blocking high modelled for Friday.These will show up within this timeframe now.

Of course tonights fax`s will be very revealling too.

These details are so important to what the medium term part of the runs will look like.

The 00z`s gave the blocking more sway but will this continue-let`s hope so--for those seeking a cold spell.

Edited January 11, 2012 by phil n.warks.

[shedhead]

I posted a chart from No 7 earlier in the thread Eye, I estimated -8c max for London in a Thames Steamer blizzard.... alas, if only!

[Matty M]

Only just seen the ensembles and my word im going to have a ramp about member No7.

http://176.31.229.22...s-7-1-240.png?6

So what would conditions be like if that came off. Well the SE in particular would get nailed with max temps around -6C, windchill below -10C and snowfall amounts possibly reaching 20 inches in a few selected locations. Away from the SE many will see snowfall and parts of Wales, W Midlands would experience very low min temps if they remained clear at night.

Sorry but I couldn't resist.

But if you track the isobar over Southern England it originates in Northern Africa, the cold would not last long.

[UV-RAY]

Only just seen the ensembles and my word im going to have a ramp about member No7.

http://176.31.229.22...s-7-1-240.png?6

So what would conditions be like if that came off. Well the SE in particular would get nailed with max temps around -6C, windchill below -10C and snowfall amounts possibly reaching 20 inches in a few selected locations. Away from the SE many will see snowfall and parts of Wales, W Midlands would experience very low min temps if they remained clear at night.

Sorry but I couldn't resist.

Yes great for you Southerners. :lol: Sorry couldn't resist, a fantastic chart no matter where you come from, off course the main thrust of any snow would be for Southern areas, but most places would get snow if that set up came about

But if you track the isobar over Southern England it originates in Northern Africa, the cold would not last long.

It wouldn't matter, as it would be a slow moving feature tracking in a SE direction.

[Cecil Hogmanay Melchett]

But if you track the isobar over Southern England it originates in Northern Africa, the cold would not last long.

Sorry matty but that is tongue in cheek?Yes?

[phil nw.]

Just a request,before the 12z outputs.

It is likely to be quite busy later so can posters please keep to discussions centred around the output.

If members wish to expand into general chat about preferences or wish to express elation/disappointment then there are plenty of threads for those.

To avoid cluttering up the thread any OT postings will run the risk of being deleted.

Thanks people.

[swilliam]

Only just seen the ensembles and my word im going to have a ramp about member No7.

http://176.31.229.22...s-7-1-240.png?6

So what would conditions be like if that came off. Well the SE in particular would get nailed with max temps around -6C, windchill below -10C and snowfall amounts possibly reaching 20 inches in a few selected locations. Away from the SE many will see snowfall and parts of Wales, W Midlands would experience very low min temps if they remained clear at night.

Sorry but I couldn't resist.

Yes it is interesting that one as it does not really come about due to trough disruption and a slider low but due to several bouts of WAA further and further West extending the Scandi ridge westwards. This is I think is why it is so cold.

Edited January 11, 2012 by swilliam

[Summer Sun]

lets see

now will the GFS trend towards METO or will it upgrade further...

GFS is now on its way out the next hour will be nail biting for some I can see it.

At 36hrs we have low pressure to our East and West in the middle is the UK under high pressure

[VillagePlank]

Here's the London 6z GEFS Analysis,

Notably, a spread of 20.6^oC on the 23rd Jan at midday! The mean is sub-zero from the 12th Jan to the end of the run with low minima of -17.8^oC, and high maxima of 7.7^oC on the 19th Jan.

The mean, again, is unremarkable; however that low minima - which represents one of the possible solutions given small perturbatons from the data input - is quite low. Best chances for the, *cough*, white stuff, is the period 23rd Jan 18z to 25th Jan 06z should this come to fruition - let's not forget that this is well into FI territory. The trend is for more members to look increasingly colder, run by run. It will interesting to compare each GFS run to itself the following day.

Nice to see, though, and certainly good for model watching

Edited January 11, 2012 by Boar Wrinklestorm

[Harsh Climate]

GFS is now on its way out the next hour will be nail biting for some I can see it.

At 36hrs we have low pressure to our East and West in the middle is the UK under high pressure

To be honest though I'm not too bothered about what the gfs12z run shows, its the esembles that come out at 6pm that are of most importance! Will we get clustering or agreement from many perpetrations?

And The ECm really has to be the main player at the moment, I'd accept that model over most of the others combined in picking up long range signals of blocking and cold from the east

[Paul]

Seriously now, it's getting beyond a joke the amount of moderating we're having to do in this thread - we keep this discussion on topic because the members ask us to, so please have some respect for both the team and the other members of the forum who want to read about the models and post into other parts of the forum if you're not going to be discussing the models.

No-one minds the odd o/t mention but entire posts filled with nothing about the models and then 10 replies to those posts are just wrecking the discussion. I hope we don't have to stop people posting in here, but it's an option.

[snowmadchrisuk]

Here's the London 6z GEFS Analysis,

Notably, a spread of 20.6^oC on the 23rd Jan at midday! The mean is sub-zero from the 12th Jan to the end of the run with low minima of -17.8^oC, and high maxima of 7.7^oC on the 19th Jan.

The mean, again, is unremarkable; however that low minima - which represents one of the possible solutions given small perturbatons from the data input - is quite low. Best chances for the, *cough*, white stuff, is the period 23rd Jan 18z to 25th Jan 06z should this come to fruition - let's not forget that this is well into FI territory. The trend is for more members to look increasingly colder, run by run. It will interesting to compare each GFS run to itself the following day.

Nice to see, though, and certainly good for model watching

With the amount of blocking that looks very likely IMO , I don't think you can put snow chances down to a 36hr period . If all that Cold air moves west and the block holds you could be looking at snow somewhere everyday for 30 days . Looking for some consistency from the big 2 now .

[nick sussex]

To be honest though I'm not too bothered about what the gfs12z run shows, its the esembles that come out at 6pm that are of most importance! Will we get clustering or agreement from many perpetrations?

And The ECm really has to be the main player at the moment, I'd accept that model over most of the others combined in picking up long range signals of blocking and cold from the east

Don't be too disappointed if the ensembles show alot of scatter, if the operational run does disrupt the trough to the west at around 144 to 168hrs hrs sending energy towards Iberia then you're likely to find that a difficult synoptic for ensembles with their lower resolution.

Shortwaves and undercutting are best handled by the operational runs within that timeframe and even then its still somewhat of a struggle for them.

[Summer Sun]

Not looking bad so far

The high pressure is getting squeezed out slowly

[SMU]

http://176.31.229.228/modeles/gfs/runs/gfsnh-2012011112-0-84.png?12

12Z Better in a few ways already- 06z had the shortwave digging over scandi at 84, where as we have almost the original link up developing again..

more undercutting as well-

So far so good +1

S

[Osbourne One-Nil]

New daily thread opening up - http://forum.netweather.tv/topic/72205-model-output-discussion-january-11th/

This one will close in a few mins.

[chionomaniac]

http://176.31.229.22...112-0-84.png?12

12Z Better in a few ways already- 06z had the shortwave digging over scandi at 84, where as we have almost the original link up developing again..

more undercutting as well-

So far so good +1

S

There was one ensemble member from the 6Z that brought in the undercutiing earlier. With the 12Z trending the same, there is a real possibilty that the easterly synoptics could be brought forward. Reminiscent of last winter anyone?

[Harsh Climate]

Don't be too disappointed if the ensembles show alot of scatter, if the operational run does disrupt the trough to the west at around 144 to 168hrs hrs sending energy towards Iberia then you're likely to find that a difficult synoptic for ensembles with their lower resolution.

Shortwaves and undercutting are best handled by the operational runs within that timeframe and even then its still somewhat of a struggle for them.

Yes, it could go either way at the moment. But I'd take the esembles having 4/5 perpetrations heading below -10hpa, than a great operational run with no other esemble members heading below -10hpa anyday!

And I can't understand how my other post got deleted. The video of Feb1991 showed pretty much the exact same synoptics as that esemble member we were discussing. And highlighted perfectly what would happen if that run came off. O well...

[Osbourne One-Nil]

I can't see anyone posting, so over to the new thread please.