Model output discussion - 5th December 2016 - Into Winter we go

[Timmytour]

My instincts tell me that we shall soon see everything a lot further South as the models get to grip with how strong the blocking really is.....

[Polar Maritime]

Lets please leave instincts/winter comparisons for another thread, And continue in here with what the Models are actually showing, Thanks. 

Edited December 18, 2016 by Polar Maritime

[northwestsnow]

7 minutes ago, Timmytour said:

My instincts tell me that we shall soon see everything a lot further South as the models get to grip with how strong the blocking really is.....

But thats the problem, there is no blocking highs at northern latitudes to force the jet south.Im certainly not going to forecast january but we really need some kind of ssw to shake up that rancid PV.Jan and feb ( well the first half of feb in my book) are the main winter months - but coldies really need to hope for some wave 2 action to disrupt the strat.The gfs highlights the problem well, all the cold is bottled up to the north, even at day 10 on ECM the deep cold is bottled up over Greenland, and thats not a good sign for us!

Edited December 18, 2016 by northwestsnow

[Man With Beard]

Wow, whizzed through the models this morning, that is some train of storms coming out of the Atlantic, as if nature has been storing up its fury for the festive period!

It does look at the moment as if northern areas will see one or two batterings before the year is out, or even more!

Southern areas will have to wait and see - there's scope for it to go either way, could avoid the storms aside a couple of squally fronts - or, equally, if the storms deepen further, they may well track south.

Odds on a Christmas Day power cut?

Snow chances today for populated areas = no chance at all probably to the end of the year.

Without that cold start to the month, we could have been looking at a top 10 mild December. Such a thin line between mild and cold when there's a block to the east, and it has to be admitted the UK is 4 out of 5 times too far west to be on the cold side.

Edited December 18, 2016 by Man With Beard

[Dennis]

2 minutes ago, northwestsnow said:

But thats the problem, there is no blocking highs at northern latitudes to force the jet south.Im certainly not going to forecast january but we really need some kind of ssw to shake up that rancid PV.Jan and feb ( well the first half of feb in my book) are the main winter months - but coldies really need to hope for some wave 2 action to disrupt the strat.

There is one actual thats need a close watch

[knocker]

2 minutes ago, Dennis said:

There is one actual thats need a close watch

I'm sure a lot of people, including me, would appreciate it if you would just expand a little on why that needs a close watch. relative to the weather likely in north west Europe in the near future Thanks.

[Nick F]

50 minutes ago, KTtom said:

This 'storm' from gfs seems to be a recurring theme for Christmas and surely deserves more attention than its getting from the Met?  I know gfs has a habit of overdoing these lows but that one really would be a bit concerning let alone the fact it's forecast for Christmas  day.

7 days is a long way off to alarm the public over a mesoscale feature that is subject to change in timing and track, but there is good support from GFS and EC ops for some damaging and disruptive winds beneath a deep low passing just north of Scotland on the 25th.

20 minutes ago, SteveB said:

I think it's fair to say the similarities between this year and the last few are starting to show there hand, I think someone mentioned last night we were on our fourth named storm by now last year, well we could easily by on that by the turn of the year.

In many way's this Winter is worse than last year as it had so much promise but ultimately led us down a blind alley to be beaten up by two thugs again.

 

There were enough pointers back in November to suggest we may have a cold start to winter, mainly the weakened state of the PV. However, there was always the risk, with a wQBO, that the strat PV would strength rapidly and that the circumpolar trop PV would drop a lobe into N America, like the last few winters, which ultimately ramps up the jet downstream across the N Atlantic.

Only crumbs of comfort I can find from the NWP this morning is the jet amplifying upstream day 10, but if this does materialise, will the amplifying trough-ridge configuration move into a favourable position for the UK to allow more Pm air or will the trough end up west of the UK and pump southwesterlies like 00z GFS?

Edited December 18, 2016 by Nick F

[Dennis]

4 minutes ago, knocker said:

I'm sure a lot of people, including me, would appreciate it if you would just expand a little on why that needs a close watch. relative to the weather likely in north west Europe in the near future Thanks.

Hi ill try to figure it out also but it isnt that easy to have a quick result for weathermodels ; these things first happen the the stratoshere and we need to wait (im sry) 

[northwestsnow]

9 minutes ago, Nick F said:

7 days is a long way off to alarm the public over a mesoscale feature that is subject to change in timing and track, but there is good support from GFS and EC ops for some damaging and disruptive winds beneath a deep low passing just north of Scotland on the 25th.

There were enough pointers back in November to suggest we may have a cold start to winter, mainly the weakened state of the PV. However, there was always the risk, with a wQBO, that the strat PV would strength rapidly and that the circumpolar trop PV would drop a lobe into N America, like the last few winters, which ultimately ramps up the jet downstream across the N Atlantic.

Only crumbs of comfort I can find from the NWP this morning is the jet amplifying upstream day 10, but if this does materialise, will the amplifying trough-ridge configuration move into a favourable position for the UK to allow more Pm air or will the trough end up west of the UK and pump southwesterlies like 00z GFS?

Interesting you mention the wQBO Nick, im pointing the finger of suspicion for the winter so far firmly in that direction.ENSO is relatively neutral, and sunspot activity is hardly rampant either.I wonder if the Russian anticyclone is connected to the wQBO, the last few winters have seen intense blocking in that region, its something i never like to see personally, i genuinally believe we are going to need a SSW to change the dynamics of the weather patterns,obviously i will watch the NWP like i do every day but handcon heart i think the very best we can hope for prior to any ssw would be pm shots, most likely brief ones..

Edited December 18, 2016 by northwestsnow

[nick sussex]

My indepth look at the models today!  Of the main ones:

GFS Total crap for cold.

ECM Less crap for cold.

To further expand, strangely the ECM is more progressive than the GFS and has a less horrific upstream pattern with large differences appearing between it and the GFS.

As Nick F mentioned the problem if the upstream pattern amplifies is where the UK will be in that set up between trough/ridge. If the troughing is to the west of the UK you'll just end up with being on the warm side of that and then end up with your sombrero on and the barbecue out .

Overall today its just levels of awfulness for coldies but if you had to pick one output it would be the ECM because that shows a sliver of hope upstream. It does have a few PM interludes, nothing much to write home about but the GFS even by recent winter standards is a horror of epic proportions for coldies.

Edited December 18, 2016 by nick sussex

[karlos1983]

Yes very underwhelming outputs overnight. GFS just highlights how difficult it may well prove to rid Europe of that high pressure, experience model watching over the years tells me it may be around for sometime longer! The problem for the southern third of the country is whilst that remains, we are stuck in this Groundhog Day of boring nothingness. Storms will track to far north and frost impossible! 

Ensembles not much to write home about either. 

 

Edited December 18, 2016 by karlos1983

[IDO]

Looking at the D16 mean and the hope many on here for the New Year to bring in some cold charts is way adrift of the mark. In fact the total opposite. A definite trend of late, though not yet consistent enough to call, of a more zonal pattern change. The D16 mean is the "winter killer" play book with low heights to the NW and a mean Icelandic Low:

  D16 ensembles are poor: here

Not even cold zonal, with the uppers for London 2-3c above average for much of FI. Thankfully its the GFS so no literal consumption this early due to its Atlantic bias during pattern changes. Looking for this to not get any consistency in the next week.

TBH GEM and ECM are also on board the zonal train to D10 with little sign of any disruption to that pattern. The GEM is the mildest with the jet the furthest north, GFS middling and ECM the coolest; but all are changeable, potentially stormy and wet. The next 2 weeks GFS rain totals: 

 Temps above average most: 

I wrote December off a while back but it looks like mid-Jan is now the earliest we can expect before a colder pattern could take hold based on current output. The usual story unfolding, but the background signals are there so whole sale changes may still happen, though confidence is low due to their failure so far in December to show their hand.

 

[nick sussex]

As IDO just showed those GEFS ensembles are poor and I've looked through the members. When even the GEFS can't pull a cold solution out of the hat then you know we're in trouble. Oh wait there was one at T384hrs! that's one solution out of 20 members at that range!

The only way is up and that's often used in here but never more true today!

[karlos1983]

10 minutes ago, nick sussex said:

As IDO just showed those GEFS ensembles are poor and I've looked through the members. When even the GEFS can't pull a cold solution out of the hat then you know we're in trouble. Oh wait there was one at T384hrs! that's one solution out of 20 members at that range!

The only way is up and that's often used in here but never more true today!

Well I think writing any cold off until mid jan is going a bit far, and there are plenty of caveats in IDO's post lol (understandably)

ensembles are crap though. Especially when looking at the last 4! Not a single member goes sub -10 850's. PANTS!

 

Edited December 18, 2016 by karlos1983

[nick sussex]

3 minutes ago, karlos1983 said:

Well I think writing any cold off until mid jan is going a bit far, and there are plenty of caveats in IDO's post lol (understandably)

ensembles are crap though. Especially when looking at the last 4! Not a single member goes sub -10 850's.

 

I think its reverse psychology, expect the worst then if something pops up then you're pleasantly surprised. I don't think he's writing cold off, perhaps those longer range tools might save their reputation!

[Summer Sun]

UKMO at t144 (Christmas eve) shows a very deep low heading towards Iceland with some strong winds possible for parts of Scotland elsewhere breezy but nothing major

Christmas Day we look to be in a westerly flow with some rain in places

Hard to tell 100% but maybe something similar to ECM?

Edited December 18, 2016 by Summer Sun

[Man With Beard]

Certainly a trend on the last few ensemble runs to reduce the number of cold possibilities, as IDO / Nick rightly point out. A little early to say this trend is confirmed right out to D14, 15, 16 - but the PV seems to have no current plans to vacate. 

[knocker]

The ext EPS late on is still looking to concentrate the vortex N. Canada with a very flat flow upstream apart from a quite strong Aleutian ridge which may, or may not, encourage some Atlantic ridging as any retrogression of HP from the east appears to be off the menu at the moment. In fact the pattern is not dissimilar to the 100mb at T360

 

Edited December 18, 2016 by knocker

[mcweather]

2 minutes ago, Man With Beard said:

Certainly a trend on the last few ensemble runs to reduce the number of cold possibilities, as IDO / Nick rightly point out. A little early to say this trend is confirmed right out to D14, 15, 16 - but the PV seems to have no current plans to vacate. 

yes mwb models showing pretty much unanimous agreement on a mobile westerly out look through the Xmas period. Time to forget the models  and go off and enjoy the seasonal festivities for a while and come back after Xmas I think when hopefully some of the signs from Glosea and ecm46  will actually start to show themselves in reality instead just existing in a computer's  miscalculations.

[Scandinavian High.]

North east America is very cold at the moment and this is beefing up the jet stream coming out of America a change to less cold for that part of world coming soon . We may see a change for U.K more settled and colder In to new year. I'm still learning I could be completely wrong on this.

Edited December 18, 2016 by abbie123

[Weathizard]

Pretty dreadful output all round this morning, just shows background signals can be useful to give rough guidelines but should never be taken as a guaruntee at any type of cold pattern. I say 'cold' pattern because milder outcomes always seem to come to fruition! 

Also the patterns showing up now are exactly why many of us get mad when people want 'zonal reset' history tells us it's the biggest winter killer going and can consume weeks, even months at a time!

At least it's Christmas time, console yourselves from the miserable charts with a nice beverage and some junk food.

[bluearmy]

37 minutes ago, knocker said:

The ext EPS late on is still looking to concentrate the vortex N. Canada with a very flat flow upstream apart from a quite strong Aleutian ridge which may, or may not, encourage some Atlantic ridging as any retrogression of HP from the east appears to be off the menu at the moment. In fact the pattern is not dissimilar to the 100mb at T360

 

Yes knocker, the eps certainly with a more zonal look this morning with the blocking from the east that had seemed likely to reassert itself becoming less obvious by the run. if anything, we would need to look west rather than east for height rises but way too far away and early for that to be analysed. the euro height high anomolies appear less strong post day 10 - the hope for coldies here is that the mean is picking up a change in that direction. 

[Gael_Force]

1 hour ago, Summer Sun said:

UKMO at t144 (Christmas eve) shows a very deep low heading towards Iceland with some strong winds possible for parts of Scotland elsewhere breezy but nothing major

Christmas Day we look to be in a westerly flow with some rain in places

Hard to tell 100% but maybe something similar to ECM?

 

Wind charts on there too.

surface wind in knots.

[Ali1977]

Is this the Atlantic high starting to slowly edge North I wonder, I think this is where we need to be looking for now - height rises to our East isn't going to happen this year with this PV.

If this one flattens look towards Canada for signs of more ridging and the jet starting to meander 

Edited December 18, 2016 by Ali1977

[fergieweather]

3 hours ago, KTtom said:

Don't really like bashing LRF, but what happened to the blocked dry December with hight to the north west..it's totally opposite. Surely it won't be long before the Met have to drop the bone, admit to a shocker, and change their outlook to a zonal theme....all the operational runs can't be wrong...Surely? 

There's no dispute re poor broadscale performance of seasonal modelling for December and consequently all output into J-F-M is viewed with great suspicion. Matters aren't helped by the divergence between GloSea5 and ECMWF products: the former offering weakly blocked Jan; indeterminate Feb; mobile March. EC meanwhile remains steadfast for pronounced blocking Jan & Feb. Both models then lean to +ve temp anomalies during spring. Thus, albeit the ongoing output opts rather more for a blocked/likely colder period developing 1st half Jan (and 00z EC clusters show over half of members heading to a mid-Atlantic ridge early Jan), this has very low confidence, given conflicting signals; weak global teleconnections and the upsurge in SPV apparently at odds with longer-lead output.