Model Output Discussion 29th December - Into mid-Winter.

[Mucka]

I know focus is more on the hear and now but I hope this is the general direction we are eventually heading in FI.

 

[Stozzy]

3 minutes ago, bluearmy said:

but does more than one of them get the latitude of the surface high n of the op? any potential widespread snowfall from the easterly/soueasterly flow would be dependent on the evolution of the euro trough and that is generally not an easy feature to model

Probably not but not far off , think this is the best we can hope for 

[Ali1977]

2 minutes ago, Mucka said:

I know focus is more on the hear and now but I hope this is the general direction we are eventually heading in FI.

 

Northerly to Easterly to Northerly with greens high,  yes that will do 

Edited January 11, 2017 by Ali1977

[chris55]

Big angry PV over Greenland....... NO! ......Blocked pattern with potential YES!

What ever the outcome of the initial easterly flow/UK high/Slack easterly flow, the general trend from both GFS and ECM is for a more blocked pattern to develop. How many recent January's have we seen the PV over Greenland firing a zonal pattern towards us with our only hope being a SSW! 

For me the models are trending very favourably, it may not be the mega easterly we all would love initially, but overall its a decent place to be mid winter regarding colder UK weather.

[A Frayed Knot]

[Cheese Rice]

The 12z Euro4 has shifted the bulk of the precipitation further south, not by a significant margin but enough to put the London area firmly at the centre of the heaviest PPN which is ideal for any evaporating cooling.

 

Somewhere like St Albans seems like the sweet spot. 

Edited January 11, 2017 by Cheese Rice

[SMU]

43 minutes ago, swfc said:

Could you see this position regarding things from the east improving ie things moving north bringing a more substantial easterly?tia

Yes it should do !!

@pinball wizard

The modelling of this belt of PPN has been solid now for 36 or so hours - it started out just over the southern counties however the Northern extent quickly developed North all the way now up to norfolk-

The question now is how fast the undercut gets into the PPN band - so rain to snow always a knightmare to forecast

Keep an eye on the dunstable downs webcam for the transition !

Northamptonshire, cambs, suffolk look good- & the latter 2 could get a top up friday Morning !!

S

[Severe Siberian icy blast]

17 minutes ago, Ali1977 said:

Northerly to Easterly to Northerly with greens high,  yes that will do 

This is exactly what I expected the gfs to give us in the op but it sort went to a West based -NAO But Yes with the vortex expected to migrate east again then we need to look West for hight rises again 

[Mark Neal.]

Euro 4 has updated, its 12z run as follows

.   

 

[pinball wizard]

2 minutes ago, Steve Murr said:

Yes it should do !!

@pinball wizard

The modelling of this belt of PPN has been solid now for 36 or so hours - it started out just over the southern counties however the Northern extent quickly developed North all the way now up to norfolk-

The question now is how fast the undercut gets into the PPN band - so rain to snow always a knightmare to forecast

Keep an eye on the dunstable downs webcam for the transition !

Northamptonshire, cambs, suffolk look good- & the latter 2 could get a top up friday Morning !!

S

Cheers for the response, I guess its the modelling of the undercut versus the PPN transferring into the North Sea that's causing the issues. Anyone got a link to the dunstable downs webcam then? Also, what sort of feature is on the cards for Monday?

[Mark Neal.]

Fridays low a bit further west with the latest Euro 4.. Spine of the country more. Midlands.

 

[Cheese Rice]

I suspect there'll be another southward correction in the models later tonight re tomorrows feature in the se.

[Mark Neal.]

7 minutes ago, Steve Murr said:

Yes it should do !!

@pinball wizard

The modelling of this belt of PPN has been solid now for 36 or so hours - it started out just over the southern counties however the Northern extent quickly developed North all the way now up to norfolk-

The question now is how fast the undercut gets into the PPN band - so rain to snow always a knightmare to forecast

Keep an eye on the dunstable downs webcam for the transition !

Northamptonshire, cambs, suffolk look good- & the latter 2 could get a top up friday Morning !!

S

The said feature (Fri morning) has on the Euro 4 moved westward in its correct with the 1z Euro 4, bringing spine of the country and midlands into play.  as steve murr has said some areas could get something from both tomorrows low and fridays morning. Oxfordshire/Buckinghamshire also a good shout Steve? 

 

Edited January 11, 2017 by Mark N

[Mucka]

2 minutes ago, Mark N said:

Fridays low a bit further west with the latest Euro 4.. Spine of the country more. Midlands.

 

It would push SE from there though so chance for some lucky folk in the optimum location to see two snow events in two days.

[swfc]

8 minutes ago, Steve Murr said:

Yes it should do !!

@pinball wizard

The modelling of this belt of PPN has been solid now for 36 or so hours - it started out just over the southern counties however the Northern extent quickly developed North all the way now up to norfolk-

The question now is how fast the undercut gets into the PPN band - so rain to snow always a knightmare to forecast

Keep an eye on the dunstable downs webcam for the transition !

Northamptonshire, cambs, suffolk look good- & the latter 2 could get a top up friday Morning !!

S

cheers steve but wrong ans!!! lol

[Eskimo]

I'm not seeing the southward correction. I don't have the previous chart to back up my point but I'm almost certain northern extent of the precipitation band is where it was earlier. Happy to be proven wrong!

[chris55]

3 minutes ago, Mark N said:

Fridays low a bit further west with the latest Euro 4.. Spine of the country more. Midlands.

 

Thats a great chart, we all want as many people as possible to see some of the white stuff and if Fridays low can extend west then loads more people may get in on the action as it heads south. NAE has been pretty consistent with Thursdays ppn lets hope it continues that consistency with the westward progression of Fridays ppn.

[nick sussex]

The UKMO looks a bit fishy to me. It goes from a good T96hrs output to a rather underwhelming T120 and T144hrs output. Although the high looks like getting further north at T168hrs.

NCEP still have put more weight in the ECM for the upstream pattern in their medium term outlook. The earlier state forecasts towards the eastern USA mentioned a slower movement east of high pressure into the Atlantic which would suggest a bit more amplitude, this was they thought a trend that could continue although the GFS and UKMO still look a bit fast. More amplitude there later could help direct the jet a bit more favourably to the ne.

 

[phil nw.]

For pinball wizard and blue army i have moved your recent posts re.snow discussion into the regional thread here

Just to keep things on topic in here.

Edited January 11, 2017 by phil nw.

[Purga]

After the 'mild' blip coming up the GEFS trend markedly to cold

These are the 850hPa (above) so don't tell the full story i.e. surface cold always important with E'ly synoptics, The T2M are below

These paint a decidedly cold picture for the foreseeable...

[SMU]

1 hour ago, swfc said:

Could you see this position regarding things from the east improving ie things moving north bringing a more substantial easterly?tia

Yes - also thats the current JMA so will update alongside the ECM !

eyes down for the eagerly awaited ECM !

[stratty]

3 minutes ago, Purga said:

After the 'mild' blip coming up the GEFS trend markedly to cold

These are the 850hPa (above) so don't tell the full story i.e. surface cold always important with E'ly synoptics, The T2M are below

These paint a decidedly cold picture for the foreseeable...

...wow that precip spike has grown and grown over the last few days for tomorrow! 

[Iceberg]

Remember tomorrow's low. It is and will be very very difficult to predict. Euro had it deepening by 16mb in the space of 8 hrs. 

That in it self is difficult to predict.  Throw in the transition from a open wave to a closed low. Then throw in exact path. Then throw in the temperature gradient and under cut of colder air. It's will be difficult to even now cast imho. 

Conversely the deeper the initial warmth the quicker the closed low the quicker the cold can be dragged down into the system. 

Also the higher up the rain and precip the longer it has to turn to snow as it exits. 

[bluearmy]

ec 12z shows tomorrows accumulations to be e hants/sussex/kent  (south of London with elevation I would say). plus Dartmoor/exmoor

[MKN]

17 minutes ago, Mark N said:

Euro 4 has updated, its 12z run as follows

.   

 

Cheshire gap streamer could see some reasonable localised falls if gets going like it has done on occasion.