Model output discussion - winter proper underway

[carinthian]

14 hours ago, carinthian said:

May be GFS sniffing out a change to the east. This 10 day NH chart shows the removal of the holding pattern over Russia, the first chart to show this for sometime now. I know the later run has the high collapsing but it could easily hold and allow low pressure to the NE to sink into Western Russia .

 C

latest gfs chart at day 10. Still a chance to recue Christmas. The quasistationary pattern now changing over Central Russia, so always a chance of the Low over Northern Russia to sink. Its an outside option but not one to be totally ignored. ECM  charts look the worse outcome. Maybe GFS holds out for the best options to advance cold into Euroland at least.  Blighty on the outside but not totally without a 40% chance I would think as it stands now at day 10.

 C

[winterof79]

For the newbies who may get drawn into thinking we are on the cusp of never ending zonal weather I suggest you read back through the thread and note Tamara and GPs posts, to name only two.

 A read of the longer term METO weather outlook would appear to lean toward a blocking high setting up in our locale after Christmas. My own personal understanding is that it could well be to our N/E.It could also be out West as the threat of snow for Northern and Central parts remains in the forecast. Plenty to look forward to and a cracking start to winter from day 1.

[sundog]

Thought this back at the end of Nov

I know I'm getting way ahead of myself here but just hope we aren't sacrificing the second half of Dec with Xmas,the more business end of Dec for a chilly first half. Can't have it all I know but just a thought. Or if the middle part of the month became somewhat milder perhaps much colder again by the end........... Overthinking it I know.

 

 

A boring second half of Dec  and Xmas period it looks like so ATM anyway...........

 

[ArHu3]

35 minutes ago, winterof79 said:

For the newbies who may get drawn into thinking we are on the cusp of never ending zonal weather I suggest you read back through the thread and note Tamara and GPs posts, to name only two.

 A read of the longer term METO weather outlook would appear to lean toward a blocking high setting up in our locale after Christmas. My own personal understanding is that it could well be to our N/E.It could also be out West as the threat of snow for Northern and Central parts remains in the forecast. Plenty to look forward to and a cracking start to winter from day 1.

Today even 3 GEFS members are going for a major ssw somewhere between the 23rd and the 29th

 

 

[johnholmes]

1 hour ago, bluearmy said:

After an exhausting few weeks, it's not surprising to see it quiet in here.  Not much to report from the overnights other than the longer term Pacific ridge remains firm and nw europe stays  more ridgy and less troughy with each run on a pos NAO background 

Surely it is not the NAO which governs the weather pattern, as you seem to suggest, but the weather pattern that gives the NAO be it + or - ve or am I totally wrong?

[carinthian]

43 minutes ago, carinthian said:

latest gfs chart at day 10. Still a chance to recue Christmas. The quasistationary pattern now changing over Central Russia, so always a chance of the Low over Northern Russia to sink. Its an outside option but not one to be totally ignored. ECM  charts look the worse outcome. Maybe GFS holds out for the best options to advance cold into Euroland at least.  Blighty on the outside but not totally without a 40% chance I would think as it stands now at day 10.

 C

Latest American Navy Model has some cold upper flow advection into mainland Europe at 180T with continental surface into the far East Of England. At least some support as to the above post. NAVGOPEEU usually good in this range as it is a powerful upgrade model and improving with its results.

 C

[Summer Sun]

Little change from UKMO extended this morning some rain around the west but drier for the majority and temps dependant on just where the high will actually be

t144 shows significantly milder air moving in but at the surface it could be cold still in some spots especially if the high brought frost and fog

[West is Best]

Although three operationals make rather grim viewings, the GFS control does offer some hope:

 

Edited December 13, 2017 by West is Best

[johnholmes]

Having looked in more detail at the anomaly charts and other data covering the 6-15 days or so I think the unsettled spell will be fairly short, certainly possible to be rather windy for NW'ern areas then settling down. Indications seem to show that an upper ridge is going to develop from the SW moving over the UK and NW Europe?

Be interesting to see if this does develop.

links to show this

http://www.weathercharts.org/ukmomslp.htm#t120

scroll down to beyond 120 h for the upper air charts

http://www.cpc.noaa.gov/products/predictions/814day/500mb.php

less marked even on the 8-14 outlook

http://www.cpc.noaa.gov/products/predictions/814day/500mb.php

GFS is much like the Met O upper air outlook re the ridging

[Daniel*]

6 minutes ago, West is Best said:

Although three operationals make rather grim viewings, the GFS control does offer some hope:

 

For what a 1-2 day cold snap I’ll pass.. there are some that keep it cold / very cold. 

[feb1991blizzard]

13 minutes ago, ArHu3 said:

Today even 3 GEFS members are going for a major ssw somewhere between the 23rd and the 29th

 

 

They're all trending back up again though, I cant see the Met Office forecast holding for very long with charts like that, yes I know that's the GFS but with the strat, I doubt that glosea5 or any other model will have a strong signal for an SSW in that timeframe whilst you are seeing charts like that, you need loads of them flatlining.

6 minutes ago, West is Best said:

Although three operationals make rather grim viewings, the GFS control does offer some hope:

 

Again, unfortunately that's just a one day snap on the control, you need to see them flatlining.

[feb1991blizzard]

3 minutes ago, johnholmes said:

Having looked in more detail at the anomaly charts and other data covering the 6-15 days or so I think the unsettled spell will be fairly short, certainly possible to be rather windy for NW'ern areas then settling down. Indications seem to show that an upper ridge is going to develop from the SW moving over the UK and NW Europe?

 

ECM ext eps looking a bit troughy very late on.

Edited December 13, 2017 by feb1991blizzard

[northwestsnow]

1 minute ago, feb1991blizzard said:

ECM ext eps looking a bit troughy very late on.

So for us a lot depends on the axis of the jet..

[frosty ground]

Looking at the GFS and the Day 10 period, a northerly has been modeled to go into Western europe (To our East) over the last two days this has been moved back west, The Control show this backed up even more and the Northerly affecting the UK (if only for a day)>

This is pretty reminiscent of how the current cold spell unfolded in the models, with the pattern backing up and the Atlantic being over played. It was only 3 weeks ago people where bemoaning the end of December before the forecast Zonal period would end (And we know how that turned out).

Might go to the bookies and put a bet on a white Christmas..... 

[feb1991blizzard]

2 minutes ago, northwestsnow said:

So for us a lot depends on the axis of the jet..

Well it is digging just a tad by the end of the suite but would need a good few days after that to get a cold spell in (assuming that's the route it goes), the attempt at a scandi ridge is further East again, there's several ways to get cold and snow in, The sinking trough and Mid Atlantic Ridge, Scandi High (far enough West) / Euro low or scandi high but influencing us with atlantic trough coming up against it giving battleground scenarios.

[northwestsnow]

2 minutes ago, feb1991blizzard said:

Well it is digging just a tad by the end of the suite but would need a good few days after that to get a cold spell in (assuming that's the route it goes), the attempt at a scandi ridge is further East again, there's several ways to get cold and snow in, The sinking trough and Mid Atlantic Ridge, Scandi High (far enough West) / Euro low or scandi high but influencing us with atlantic trough coming up against it giving battleground scenarios.

I'll take that as a positive Feb-

Doesn't sound like a prolonged raging +NAO to me longer term..

Hopefully the MJO will be starting to have an impact on the Atlantic profile? 

Its a trend hopefully that will gain traction in the coming days..

[TEITS]

After yesterdays 06Z gave us a glimmer of hope its back to dire output in the medium/long range. I noticed the Met O have extended the milder, more changeable weather to beyond Xmas now.

Like I have been repeating I really would forget about this whole E,ly idea via a Scandi HP. Infact in the longer range i.e +300 the GFS is consistently predicting S/SW,lys into Europe and Scandi.

[chris55]

8 or so members take a nose dive just into xmas week, perhaps this will be the next trend to watch after we enter the milder spell next week.

[feb1991blizzard]

6 minutes ago, northwestsnow said:

I'll take that as a positive Feb-

Doesn't sound like a prolonged raging +NAO to me longer term..

Hopefully the MJO will be starting to have an impact on the Atlantic profile? 

Its a trend hopefully that will gain traction in the coming days..

Well no its not really a positive, I was just saying those are the routes it could go, but could just as easily have the Jet aimed at us for a week after that.

EDIT : I just hope the MO predictions of colder drier in Jan and the views of the experts scandi high option aren't based on an SSW, because that is looking less and less likely IMO.

Edited December 13, 2017 by feb1991blizzard

[Frosty.]

19 minutes ago, frosty ground said:

Might go to the bookies and put a bet on a white Christmas..... 

It will be a very green Christmas with a hint of yellow as the daffs flourish in the balmy warmth if the Ecm 00z verifies..ho ho ho I can't resist a bit of gallows humor after seeing the 00z runs.

 

 

Edited December 13, 2017 by Frosty.

[Nick F]

29 minutes ago, johnholmes said:

Having looked in more detail at the anomaly charts and other data covering the 6-15 days or so I think the unsettled spell will be fairly short, certainly possible to be rather windy for NW'ern areas then settling down. Indications seem to show that an upper ridge is going to develop from the SW moving over the UK and NW Europe?

Yes, strong agreement from EPS/GEFS means and the operationals at day 10 of a strong ridge being extended NE from the Azores across NW/W Europe. GEFS/GFS op more bullish with northern extent of the ridge.

The forcing of the Azores ridge NE initially appears to be driven by a lobe of the trop PV over northern Canada / Davis Strait dropping into the NW Atlantic - which eventually lifts out and flattens the flow.

But notice the -EPO ridge building poleward, the extended EPS out to day 15 appears to me to edge the trop PV to our NW further SE toward the Atlantic, a result of the ridge over Alaska, thus lowering heights over the Atlantic and driving a more southerly track in the polar front jet. This would indicate a more southerly storm track over the Atlantic after Xmas Day, perhaps some cold zonality. While the GEFS mean keeps the SW to NE orientation of the 500mb flow deep into the extended range

So a strong high pressure signal for next week and maybe into Christmas week too, the south looking rather dry post Friday, though Scotland and N. Ireland prone to Atlantic fronts. Those hoping for dry and frosty weather maybe disappointed, as it could be rather cloudy, given the flow will be off the Atlantic and rather moist. Boring as hell weather in my eyes, but I guess it will please some.

Edited December 13, 2017 by Nick F

[bluearmy]

41 minutes ago, johnholmes said:

Surely it is not the NAO which governs the weather pattern, as you seem to suggest, but the weather pattern that gives the NAO be it + or - ve or am I totally wrong?

Totally right jh

i was trying to illustrate the positioning of the trough/ridge by referencing nao background  

[JamesL]

Indeed @frosty the 0z gfs ensembles are not without interest. 

[northwestsnow]

SE hangs on to the colder air at the surface through next week- pretty much coming up to the shortest day so i would imagine temps will fall quite low esp overnight in this setup-

the 850s tell a different story

But at the surface i'd suggest next week looks pretty nippy!!

Edited December 13, 2017 by northwestsnow

[frosty ground]

22 minutes ago, Frosty. said:

It will be a very green Christmas with a hint of yellow as the daffs flourish in the balmy warmth if the Ecm 00z verifies..ho ho ho I can't resist a bit of (Off Topic Nonsense) gallows humor after seeing the 00z runs.

 

 

So if the ECM OP Verifies as is.