Model Output Discussion - Stormy Period Inbound...

[A.J]

A little snippet, especially for newer members.

 

It can be daunting posting in the model threads, especially at first..........One of the more common questions in here during the winter months are questions on potential snow distributions, and unfortunately more often than not, these questions get buried in the amount of posts of more specific model output discussion. With that in mind, here are a few links for all newer members to acquaint themselves with the model outputs & possible FAQ's

 

How to follow the models without getting too stressed out!  https://forum.netweather.tv/topic/75011-how-to-follow-the-models-without-getting-too-stressed-out/

 

Ensembles - A Beginners Guide https://forum.netweather.tv/topic/66592-ensembles-a-beginners-guide/

 

Basic Gfs Charts-How To Understand And Use Them https://forum.netweather.tv/topic/64122-basic-gfs-charts-how-to-understand-and-use-them/

 

Guide To ... Uk Winter Setups  https://forum.netweather.tv/topic/56318-guide-to-uk-winter-setups/

 

Will It Snow??    https://forum.netweather.tv/topic/23729-will-it-snow/

 

The NW Regional Weather Discussion Threads      https://forum.netweather.tv/forum/142-regional-discussions/

 

hope this all helps 

 

 

[Snowmadsam]

ECM would be a total snow fest for large swathes of England barring the EXTREME SE of the UK.....

 

Also GFS p still singing the easterly

 

http://modeles.meteociel.fr/modeles/gfsp/runs/2015011312/gfsnh-0-156.png?12

 

Scotland, Wales and Northern Ireland DO also exist as well....with most seeing snow under that particular scenario

 

Devil is as always in the detail, but I'm content with the current situation lets just see how it develops/what it develops too 

[SMU]

Not sure I follow that. Not the cold bit but the purge. As far as I can see the low is moving slowly SE with build up of heights to NE.

 

Chart courtesy weatherbell

 

see here- heights building NE

 

 

In terms of the comment around no snow for SE its because of the alignment of the low-

 

http://www.meteociel.fr/modeles/ecmwf/runs/2015011312/ECU1-168.GIF?13-0

 

Note the low has deepened & in the SE quadrant is dragging up an onshore flow from the channel & SW, whilst the uppers are condusive to seeing snow & it actually may snow the prospect of lying snow is reduced.

 

However not to fear- as a rule of thumb the 168 chart has never verified for snow in the exact forecast location so don't worry, what we do however want to see is a shallower low & or an elongated low - which then due to its shape doesn't force as much mixing from the milder SW-

Southerly / SE winds are fine.

heres a classic elongated trough.

 

http://modeles.meteociel.fr/modeles/reana/1996/archives-1996-2-6-0-0.png

 

S

 

PS yes sam Wales would take a pounding from that low -

Edited January 13, 2015 by Steve Murr

[snowsummer]

Thanks for all replies. Im off to spend the night reading all thats been recommended (whilst peeping back on this thread every few minutes just in case I miss sonething!!!)

[knocker]

see here- heights building NE

 

ECM216.jpg

 

 

Ah. I wasn't aware you were talking NE of Newfoundland.

[knocker]

The ext GEFS anomaly is having none of this setup vis a vis D10 and by T360 has the vortex over Hudson (familiar) with the trough SE over the UK and into Europe. HP eastern Atlantic running west. Thus LP to NW but an Atlantic dominated by HP with a westerly flow over the UK.

Edited January 13, 2015 by knocker

[Hotspur62]

Wow,what a day model watching. Already been 12 pages today and we still have 4 hrs of the day left. Lets hope final GFS falls into line with other models and gives us one last classic pub one!!

[Paul]

Just for info, the gfs parallel runs will be available up to tomorrows upgrade of the main gfs but it will be late each time as NCEP have started the upgrade process behind the scenes..

[bluearmy]

Another WSI contribution to the public of ecm - this time the 11/15 day cluster - 52%

Edited January 13, 2015 by bluearmy

[Frosty.]

I have a feeling we are going to see many even more severe wintry charts as time goes on..this is just the beginning folks. I thought i would post these from the Ecm 12z tonight, if anything like this verifies then some of us will be buried in deep snow next week, as I said a few times today, all roads lead to cold and many of those roads will need snowploughs to clear them soon. :-)

[Jason M]

Does anyone know if the GEFS will be upgraded at the same time as the para takes over from the current GFS? I'm assuming they would be?

[knocker]

image.jpg

Another WSI contribution to the public of ecm - this time the 11/15 day cluster - 52%

 

That's not a million miles away from the GEF T360. Apart from the vortex over Hudson that is.

Chart weatherbell

Edited January 13, 2015 by knocker

[Hotspur62]

image.jpg

Another WSI contribution to the public of ecm - this time the 11/15 day cluster - 52%

Am still learning but having looked at this, this shows blocking North,NE and West of UK which is surely good news for cold spell continuing.(I know it hasn't started yet but I am assuming that it will lol).Sorry if I have misread this but am I right in this assessment?

[craigore]

ECM would be a total snow fest for large swathes of England barring the EXTREME SE of the UK.....

 

Also GFS p still singing the easterly

 

http://modeles.meteociel.fr/modeles/gfsp/runs/2015011312/gfsnh-0-156.png?12

why ??? The extreme  S.E seems to have just as cold uppers as the rest of the u.k on this evidence. tell me if im wrong !.

[IDO]

Does anyone know if the GEFS will be upgraded at the same time as the para takes over from the current GFS? I'm assuming they would be?

Q3 of 2015.

[snowy weather]

I have a feeling we are going to see many even more severe wintry charts as time goes on..this is just the beginning folks. I thought i would post these from the Ecm 12z tonight, if anything like this verifies then some of us will be buried in deep snow next week, as I said a few times today, all roads lead to cold and many of those roads will need snowploughs to clear them soon. :-)

Does that include South East as well?

[Long haul to mild]

Am still learning but having looked at this, this shows blocking North,NE and West of UK which is surely good news for cold spell continuing.(I know it hasn't started yet but I am assuming that it will lol).Sorry if I have misread this but am I right in this assessment?

As I understand it, these are anomaly charts, which means that higher than usual pressure is expected is the areas you mention, but it doesn't necessarily mean that actual blocks will set up there, especially if these areas are usually subject to low pressure.

Anyway, bluearmy will no doubt give a far better explanation than I can!

Edited January 13, 2015 by Long haul to mild

[Jason M]

Q3 of 2015.

Thanks IDO

Hmm, that's going to make the rest of this winter interesting because it's going to make it harder to gage the validity of the new opp run. Just look at the differences tonight between new and old. Whichever turns out right, it's no surprise that the GEFS go with the opp largely in the longer term.

Edited January 13, 2015 by Jason M

[Hotspur62]

As I understand it, these are anomaly charts, which means that higher than usual pressure is expected is the areas you mention, but it doesn't necessarily mean that actual blocks will set up there, especially if these areas are usually subject to low pressure.

Anyway, bluearmy will no doubt give a far better explanation than I can!

Many thanks

[bluearmy]

that wsi chart looks like a decent chance of a continuation of cold to me.

 

anyway, just a note on the ecm spreads days 9 and 10. 

 

note the likely angle of the azores ridge day 9 and then day 10

 

                

 

that would seem to show that whilst the azores tries to cut off the euro trough day 9, it is drawn back nw again at day 10 which would allow the next system to slide se, likely to the west of the uk

 

it should also be noted that the extended ecm, slowly dribbling out, then push that ridge back ne (after the system has headed se into the euro trough) which effectively brings us under the influence of higher heights wjth the euro trough losing its influence. definitely a trend now on the extended eps to sink that euro trough a bit quicker in the 10/15 day period whilst we come under the ridge sinking ese. 

 

EDIT: the latter stages of the ecm extended seem to show that the uk under the influence of the ridge which has also pushed into w europe but i see some signs of retrogression in two weeks time as the deepening n american trough pulls the ridge back west and potentially allows the trough to then dig down into europe again.

Edited January 13, 2015 by bluearmy

[Smiler1709]

As stated by others on here, I wouldn't worry about where snow will fall, let's get this cold in and entrenched then let the fun begin. I'd be surprised if all of us didn't see at least some falling snow if the models come true. But I'm still very cautious, gfs 12z was very quick to kill the cold and the others could easily follow in the coming days. Just enjoy what there churning out ATM then wait and see

[IDO]

As I understand it, these are anomaly charts, which means that higher than usual pressure is expected is the areas you mention, but it doesn't necessarily mean that actual blocks will set up there, especially if these areas are usually subject to low pressure.

Anyway, bluearmy will no doubt give a far better explanation than I can!

Looks like a cross polar flow so a relatively blocked pattern if it verified. So if we got a cold flow over the UK it would have some longevity IMO. However it is a cluster anomaly so it is only the most likely scenario with 53% support.

[stewfox]

Does that include South East as well?

 

You are going to upset JH if people keep going on about will it snow in the South East in 5 + days time (ref SM comment)

 

Any modeling that far out is likely to change and my best advice is look out of the window as we approach T0

[terrier]

I have a feeling we are going to see many even more severe wintry charts as time goes on..this is just the beginning folks. I thought i would post these from the Ecm 12z tonight, if anything like this verifies then some of us will be buried in deep snow next week, as I said a few times today, all roads lead to cold and many of those roads will need snowploughs to clear them soon. :-)

think I will refrain from opening the Stella's at the moment frosty. Still outside the reliable timeframe at mo. But as u say looks good. But until I see these charts at t48 I'm going to remain cautious. As I've seen it go wrong so many times. My philosophy with the gfs ECM ukmo is expect nothing and hopefully they move into reality.

[Geordiesnow]

Some decent output tonight if rather messy and complicated looking but those details are no doubt subject to quite a bit of change so no doubt there be some opinion on what is a good run and what is not a good run. 

 

For me personally its good too see this weekends Northerly being toned up and the mid atlantic heights are a little stronger as a result, still time for the detail to change but at least it means the weather is likely to stay on the cold side. 

 

As for an easterly, I don't see too much sign of an easterly as of yet, there is hints but that all it is at the moment, I would rather see a more clean Northerly or an Easterly as the slack set ups can deliver the goods for some but frustration for others however it be interesting too see how things develop in the coming days.