Model Output Discussion - The Start Of Winter

[Cheshire Freeze]

Oh aye, what do we have here? Much better and more amplified than what we were seeing 24 hrs ago

 

[No Balls Like Snow Balls]

This is a good good ggggggggooooooooooooooooooood upgrade for chances of significant cold from the GFS.

It's big shame it's outside the reliable time frame just yet though, but hey we have to start somewhere.

Edited December 5, 2014 by No Balls Like Snow Balls

[Barry12]

DAY 7 IS CRAZY!!!!!

 

Edited December 5, 2014 by Barry95

[knocker]

Hmmm :-) - be careful what you wish for Knocker. That chart you post - from FI of course - rather proves Blast's point. Pressure rising in the vicinity of Greenland as the vortex relocates to Siberia as at the end of the run the NH profile shows ridging from Greenland to Siberia and a system that is pulling North and soon northeasterly air in with it. It ends up here:

 

A couple of points.

 

1. I wasn't wishing for anything.

2. The chart(s) I posted happened to be in F1 to illustrate my point.

3. This point was that there could equally be a different interpretation to, "This is the point where 06 z changes its plan from previous, note the area south of the southern tip of Greenland.  That's where the trough over Newfoundland is getting held up as the ridge from greenland is holding its advance up". That being instead of a vitually non-existent ridge the jet could actually have been causing the delay of movement east.

4. I wasn't concerned with the ultimate aim of finding an arctic blast.

[Banbury]

http://modeles.meteociel.fr/modeles/gfs/runs/2014120512/gfsnh-0-168.png?12

 

Nothing zonal about this from GFS

[Mucka]

One thing is for sure. Next weeks weather will not be dull and certainly will not feel mild.

 

[Ali1977]

Surely this can't be right, lots of egg in many people faces if so. Tonight's ECM will be hotly anticipated.

[jmatt81]

Warning from Matt Hugo and Recretos on Twitter:

 

Please RT: 12z GFS is a "red" run, with high data shortage in the inputs. Should be fun

 

[Ravelin]

Big changes on latest run. We go from this....

 

 

To this.....

 

 

The low off the eastern seaboard of the US is held back and much stronger ridging toward greenland as a result. Almost getting a NEerly from that in the UK.

 

Edit: Maybe the "red" run in action?

Edited December 5, 2014 by Ravelin

[Banbury]

http://www.wetterzentrale.de/pics/Rtavn1803.gif

 

The 510 in touching distance of Scotland , that is a long fetch Northerly

[TSNWK]

Warning from Matt Hugo and Recretos on Twitter:

 

Please RT: 12z GFS is a "red" run, with high data shortage in the inputs. Should be fun

 

Just when it was starting to look exciting.. So do we bin the GFS 12z folks?

[gottolovethisweather]

To my mind, any talk of the Azores High having an influence on our shores is madness, the only model runs to show that kind of outlook has been the overnight GFS runs, outside of the 12z. The ECM and UKMO have continually trended away from any HP visitations by a long shot too. The latest UKMO 12z at t+96 shows the low coming into the far NW of the British Isles and is shown to be within the region of 940mb when just off mainland UK. Cool to Cold PM influenced zonal is the route the weather is taking over the next five to seven days, but we must be wary of taking too much notice of any outputs beyond 120hrs as it all could change beyond the deep depression and how it interacts with Jetstream before and after D5 will have obvious ramifications.

 

The current UKMO modelling suggests the following for next Tuesday.

 

 

 

Some wintriness about on Sunday into Monday for a few for us beforehand, away from lower levels prior to the chart shown above.

Edited December 5, 2014 by gottolovethisweather

[Mucka]

Just when it was starting to look exciting.. So do we bin the GFS 12z folks?

 

No, just treat it with suitable caution. It is actually not breaking any trends with that output but it is a little "out there"

Should be very interesting JMA and ECM runs tonight.

[TSNWK]

No, just treat it with suitable caution. It is actually not breaking any trends with that output but it is a little "out there"

Should be very interesting JMA and ECM runs tonight.

Will do Mucka.. Good to have a bit of a rally on this thread on the 1st Friday in December and then felt a little deflated..

[shaky]

Its funny how comments of the 12z run being a red run have come out now just when it shows a beauty of a run!!! From experience i find the 12z and 00z run the most accurate out of the 4 runs! ! Only thing maybe is that the 12z run has an eastward bias sometimes therefore more progressive.

[Iceaxecrampon]

12Z Rolling Out

 

Arctic Pipeline opening?

 

 

Friday

 

 

Should please the Southern contingent.

 

 

 

Ian

Edited December 5, 2014 by Polar Maritime
To take long blank spot out.

[Cheshire Freeze]

I think the biggest plus point at the minute is the trend to lift the deep low heights away from Canada/Greenland, if this occurs then half of the battle is won.

[mcweather]

Looks like the 12Z GFS is trying to bring us a polar low next weekend;

[nick sussex]

Just when it was starting to look exciting.. So do we bin the GFS 12z folks?

No because its solution is within what could be expected if the upstream pattern was favourable. The UKMO although slightly different over Europe at T144hrs supports the GFS in terms of the slow moving low upstream and ridge developing ready to move east towards Greenland.

 

We often see some areas with lower data, if the run was that bad NCEP would have abandoned it.  There is still however uncertainty with the pattern over the USA so we should expect more changes , these could be even better for cold or less good.

[Captain Shortwave]

Upstream looks a bit of a mess with growing agreement on low pressure becoming cut-off over Eastern Canada. This allows a wedge of heights to build over North east Canada. We would need to ride our luck with the Greenland lobe of the polar vortex as any low pressure system could easily drop too far west to bring cold weather to the UK (West based -NAO)

Rather dubious of any colder weather developing from here a secondary low spawns to our west.

Further upstream, how long does this Canadian low remain cut off, the GFS re-engages this low with the next trough and pushes the lot eastwards, this gives us the northerly at days 7/8

Tough one to call. If the high holds firm beyond day 6 then we could miss out, if the low starts to shift eastwards as the next trough over Canada approaches then we could get anything from a brief PM incursion to a full blooded northerly depending on how the cut-off low and approaching trough interacts.

Edited December 5, 2014 by Captain shortwave

[The Eagle]

UKMO is ok as well. Just a pity it flattens things again by 144hrs a little bit. But even then real potential

 

 

http://www.meteociel.fr/ukmo/runs/2014120512/UW144-21.GIF?05-17

[Cheshire Freeze]

Right at the end of FI but pleasing to see...

 

 

No organised vortex there

 

Warming showing up nicely aswell

 

 

Could this be the January we've all been waiting for?? Tune in in 4 weeks time to find out!

[Banbury]

Next Saturday looking and feeling raw

http://www.wetterzentrale.de/pics/Rtavn19217.gif

 

http://www.wetterzentrale.de/pics/Rtavn1923.gif

[Eskimo]

A lot of potential here for something quite lovely to develop

 

Just a comparison for a little tease is the chart for the same date in 1962. The vortex 50 years ago was much stronger!

Edited December 5, 2014 by PerfectStorm

[mushymanrob]

 

... and theres your pattern change in week three!