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

[Ali1977]

Not long till the EPS, I have a feeling all will be v good. Then we just need a pub run special please!!

[Paul]

Please folks can we keep it to the models in here, it's been like trying to herd cats at times this afternoon, although that said, cats don't send abusive pm's to you for simply trying to keep things on topic and friendly. 

[supernova]

It cannot be coincidence that charts like the ECM240 are as rare as rocking horse poo....and the chances of it actually verifying are similarly unlikely. That said, it's a delight to have some colder weather incoming in the reliable, and the number of ensemble members tending colder still are increasing as an overall trend despite the usual scatter.

Edited December 28, 2016 by supernova

[johnny1972]

3 hours ago, frosty ground said:

You made a guess with no supportive evidence from any actual model and now your doing the same..... just think you need the correct thread to ha either your guesses aired

I think if you look back at mountain shadows posts it is far from guess work but his analysis of the output coupled with his knowledge of the AMM, MJO and Stratosphere state that are guiding his analysis. The 2 critical posts offer nothing. I'm sure most on here could predict cold and snow will occur at some point in January, it being a winter month.

[Aaki Khan]

Regardless Of Outcome One Must Enjoy The Epic Runs. #LaLaGaGa

Sorry If Moi Breaking Any Rules.

[Geordiesnow]

Here we go again, the all too infamous day 10 type posts. Honestly, I think in the last 4-6 weeks on here, that is all I have read on here but each to their own I suppose if they want to get sucked into the details shown at 10 days time.

The outlook is interesting though and fairly promising for cold lovers but remember when seeing charts about projected Greenland highs via Atlantic ridges. They will always show in the longer range without any trouble because its so far out and in the GFS case, will be run at a lower resolution but not only that, 9 times out of 10 you will get a shortwave popping up in the medium term so in turn we get what we are going to get for new years day which is a Northerly toppler which just about lasts a day. 

Alot of uncertainty what will happen after this Northerly toppler apart from the fact it should turn less cold from the NW. Do hope we will see some retrogression but I just can't get carried away by an ECM run showing a smooth progression of heights to Greenland as its too far out to nail down any details and the fact the ECM is known to over-amplify at times.

Although i do class this upcoming as a Northerly toppler, it is quite a cold Northerly and  snow looks rather limited to Northern Scotland and perhaps down the east coast also but its the windchill that will be the main story as we head into 2017.

[doctor32]

10 minutes ago, Ali1977 said:

Not long till the EPS, I have a feeling all will be v good. Then we just need a pub run special please!!

Where can i look at the eps? what site?

[Dominic Carey]

Hello all I'm new here I thought I join because I've been reading for a few years and I'm obsessed with extreme weather events so I thought I'd take the plunge. I may not post much, sorry if I posted in the wrong forum.

[bluearmy]

thought I would post a section of ens charts from day 10 and day 16 (taken from today and yesterday) 

GEM ens are current only because I can't get yesterday's offering. GEFS and eps are today and yesterday

this mornings eps day 10 stands out as being the worse on offer. Will know within fifteen mins if that remains the case

check them out and tell me how you can be depressed about the possibilities of proper cold within the next fortnight

You will need to click on them to see their source and timeframe/run

[bluearmy]

6 minutes ago, doctor32 said:

Where can i look at the eps? what site?

Meteociel - ecmwf moyenne

[Frosty.]

4 minutes ago, Geordiesnow said:

Here we go again, the all too infamous day 10 type posts. 

 

 

Well day 10 is worth discussing..a lot when it shows this. I think it would be very boring if we stuck rigidly to the reliable timeframe and didn't comment on the extended range!

[Man With Beard]

12 minutes ago, Dominic Carey said:

Hello all I'm new here I thought I join because I've been reading for a few years and I'm obsessed with extreme weather events so I thought I'd take the plunge. I may not post much, sorry if I posted in the wrong forum.

Welcome Dominic! So what do you make of the models tonight? Do you think a kaboom is on the way or a let-down?

 

8 minutes ago, bluearmy said:

thought I would post a section of ens charts from day 10 and day 16 (taken from today and yesterday)

check them out and tell me how you can be depressed about the possibilities of proper cold within the next fortnight

Great post BA. I was 55/45 in favour of the reload but your clear demonstration has made me go up to about 65/35. With a small chance of an undercut leading to a meeting of Atlantic and cold ... oh my goodness, it's only the people who don't want cold who'll be having nightmares tonight

Edited December 28, 2016 by Man With Beard

[snowwman]

26 minutes ago, supernova said:

It cannot be coincidence that charts like the ECM240 are as rare as rocking horse poo....and the chances of it actually verifying are similarly unlikely. That said, it's a delight to have some colder weather incoming in the reliable, and the number of ensemble members tending colder still are increasing as an overall trend despite the usual scatter.

Does seem unlikely with the strong vortex to the North, but GFS Para supports a shifting of the vortex to Siberia over the past 24 hours' available runs. This may be what ECM is in the process of doing in this chart.

Edited December 28, 2016 by snowwman

[Dominic Carey]

I have a feeling it will be a kaboom run just based on all the factors there were heading into this winter. How long do people think it be until warnings get issued?

[Summer Sun]

Better than this morning

Plenty of dry and cold weather to be had with the chance of some wintry showers in the east

Edited December 28, 2016 by Summer Sun

[swilliam]

Well the  ECM ensemble mean is similar but slightly better than this morning. You could not say it directly supports the op  with the mean ridge further E than the OP which must be one of the most favourable outcomes.

 

As expected a lot of variance round the S tip of Greenland

 

One of the colder options at D10 at De Bilt but not the coldest by any means - so probably still all to play  with the OP being a possible if less likely outcome.

 

Edited December 28, 2016 by swilliam

[doctor32]

Still think it won't be until we get our first northerly shot this weekend before we know where we go afterwards... ecm op looked to me to be on it's own tonight.

Both warmest after initial cold spell this weekend then the coldest after the 6th... however in line with the gefs for a cold shot this weekend followed by slightly less cold till the 6th/7th then another cold shot.

Question is will the second shot deliver the goods???

Edited December 28, 2016 by doctor32

[draztik]

1 minute ago, doctor32 said:

Still think it won't be until we get our first northerly shot this weekend before we know where we go afterwards... ecm op looked to me to be on it's own tonight.

True... worth noting, the EC Control sends the UK into freezer into days 10-15; ens mean also promoting a cold signal beyond day 10.

[festivalking]

19 minutes ago, Dominic Carey said:

I have a feeling it will be a kaboom run just based on all the factors there were heading into this winter. How long do people think it be until warnings get issued?

When it gets to t24 when it comes to cold severe weather!

[stewfox]

So reviewing the last 24hr.

Yesterday evening inc pub run

General upbeat mood as German met man is warning of a siberian whip effect could well about to lash in western Europe and Christmas data issues finish until next year.

The smallest of teleconnective "puffs" maybe all we need!

ECM eps mean chart at t240 is good. 

CFS is forecasting the mother of all easterly’s and -16c upper 850s over central England in la la  12/1 (but hey you will get  lot of rep for that).

Gfs18z looking like a much cleaner reload for cold. This at day 6 not la la.

JMA looking fairly similar to tonight's ECM at day 10 with a possible reload.

Folks then talk about reliable and forget T240.

Morning

A couple of notable upgrades at 96-120 from the UKMO/GFS:

GEM looks. Fantastic for 2/1.

00z GFS in the shorter term looks like an upgrade in terms of depth of cold in the northerly NY day  into Monday, with -10c T850s getting south of Devon and Cornwall,(the place with palm trees).

As panto gets going bad news folks - it seems that the extended eps have flipped to what looks like a positive NAO.  Nowhere near as good as last night's set.

ext eps have moved away from the cold scenario this morning and the euro slug want go. (Oh yes it will oh no it wont).

Folk mention form horse ECM form horse increasingly preferring a return to milder Atlantic Westerlies and some rain alternating with colder polar maritime NW'lies.(sure read below).

Afternoon

Lots of negativity.

shortwave in northeast Canada remains a pain as it stops our high from retrogressing west.

It looks like were stuck in the same rut that we have been in ever since December began.

High pressure edging in from the West sitting over the UK for  a few days as it slowly makes it's way South and East into Central Europe. 

Not good (read awful) 12z output for coldies from UKMO and GFS in the more reliable. Snow chances and cold upper air very limited and short lived as per the out put at the time.

GFS 6z is bringing slightly above average temperatures to the UK after the brief cold short incoming. Different from the 0z, which was keeping things at or below average.

You’re a tos**** no you are type of stuff 3435 posts deleted and 242 one-liners,and thread goes off topic. One survives “Sadly, the 36 hour shot on New Years is as good as it gets in the foreseeable!”

Evening

GFS 12z gives another short-lived northerly late next week.

Party mood grows The ENS do not support the Op and look much better at day 8. No spoiler low.

Best set of ENS this season coming up - v good now average -6/7 at day 11.

The 12z GEFS much more amplified in the 9-12 day range.

GEM has an alternating pattern for early 2017 with a mix of colder air and some milder air (sod milder).

ECM and GFS almost identical at t120, here comes the crucial period...

The ensembles represent an upgrade. 

Gfs ens are really strong for some severe cold. Approx 10 have what could be called severe cold sub -8 850s. 

ECM day 8 looking good, and following some of the better GEFS creating a good block to our NW- an important EPS tonight, if it back the colder GEFS I'd say this is very noteworthy. Lets see what's showing at 240 first though.

KABOOM

Perfect wedge splitting the jet - note the 2 lows - just like 2010- 1 low either side of the GH ( NW side & SW side ) Folks get the 2010 bit.

Ecm det, a million miles better than that 12z gfs!.

For coldies, an excellent ECM run, and the GEFS output is decent, too, even to day 16.

Gibby getting more interested. Worth 44 rep points, how about Ian Brown what would that be worth with ‘ I don’t believe it’ ?.

But some of this is T240

Cold 5/10 ( a lot of potential T240 if nearer cold number goes up).

Potential ECM rocks we need however solid rock don’t rock it.

 

 

Edited December 28, 2016 by stewfox

[Summer Sun]

 

[Zakos]

Superb ECM mean. Goodbye Euro High!

Looking further ahead, looks like the ECM mean is still hinting towards a second northerly.

The mean anomaly at Day 10 shows good support for the operational. There is clearly a very strong signal for heights to build in this region.

Exciting times ahead.

 

 

 

 

Edited December 28, 2016 by Zakos

[bluearmy]

As posted, the eps are half way between the 00z run and yesterday's 12z run which was on the same page as the 12z op from today. At least that's a correction in the cold direction. What is of interest is that, despite not being able to post in here, the extended eps are very 12z GEFS with their anomolys late on which is much closer to yesterday's 12z than this mornings 00z. the control is cold porn towards the end of the run as the Dutch ens will shortly show. Not one to mention the control usually but when it shows uppers of -15c across se England, it deserves a mention! 

[SMU]

The ECM mean @240 certainly lends 'more' support to the OP than against- you wouldnt get that sort of wave up to greenland unless there was a majority vote-

The good news is with a Greenland high there is usually more margin of error in terms of cold air filtering south- rather than an easterly that has a small corridoor..

Anyway ECM op is 10/10 especially for the North- but it would only be the start...

wouldnt it be ironic if it was the start of a 1962/63 redux !!

[damianslaw]

As ever sticking to the reliable.. roughly 144 hrs, the models all in strong agreement, current high will shift southwards with a milder interlude from the north for 30-31, then a cold front moving down on New Years day with heights building and ridging north through the atlantic, resulting in a cold northerly, but a toppler, with heights then collapsing somewhat behind, but maintaining central core over mid atlantic. So a very changeable period ahead with threat of some snow showers in Scotland and exposed NE coastal parts to greet the new year.

Where do we go after? Both GFS and ECM suggest a WNW flow for the first few days of 2017 bringing generally dry average conditions with a bit of rain in NW parts, and a fair amount of cloud. Not particularly inspiring, but could be far worse.

Keeping an eye on the jetstream profile, indications it will maintain a split flow, with energy possibly transferring more into the southern arm, this combined with PV projected to shift more towards Siberia and a second lobe kept far from Greenland, would lay the foundations for the mid atlantic high to ridge into Greenland proper. So all eyes on jetstream and developments over NE USA seaboard in the days ahead, for those seeking a colder outlook with high lattitude blocking you need energy to transfer into the southern arm of the jet - an equal distribution as we will have in the opening days will maintain the status quo of mid atlantic heights and only fleeting northerly incursions I would imagine.