Model output discussion - 1st December onwards

[Glacier Point]

Nice trend on EC week 3 to 4, taking mean trough to the north and eastwards. Not unexpected although still with a +AO/+nao signature but more of a more west or NW flow. Scope for northerlies given some amplification which the model won't pick up at that range. Let the trend be your friend.

[feb1991blizzard]

1 minute ago, Glacier Point said:

Nice trend on EC week 3 to 4, taking mean trough to the north and eastwards. Not unexpected although still with a +AO/+nao signature but more of a more west or NW flow. Scope for northerlies given some amplification which the model won't pick up at that range. Let the trend be your friend.

Is there anything significant happening up top in weeks 3 to 4 please, I would hope something significant showing by then at least in a small cluster.

[Cheshire Freeze]

Interesting, split vortex showing now at the end of FI on the 18z

 

 

WAA driven right to the pole. POW!, right in the kisser

Edited December 17, 2015 by CreweCold

[Glacier Point]

Nothing at H500 that might suggest so, but that's right on the edge of potential time lines.

[feb1991blizzard]

 

These are the charts I want to be seeing more of rather than brief North Westerlies, short term pain for long term gain, I'm an all or nothing, concerning that the tack has been changed to PM incursions on the last few runs than bitter albeit a longer wait Easterlies.

[feb1991blizzard]

Just now, Glacier Point said:

Nothing at H500 that might suggest so, but that's right on the edge of potential time lines.

cheers.

[Nick F]

38 minutes ago, Glacier Point said:

Nice trend on EC week 3 to 4, taking mean trough to the north and eastwards. Not unexpected although still with a +AO/+nao signature but more of a more west or NW flow. Scope for northerlies given some amplification which the model won't pick up at that range. Let the trend be your friend.

Looks a lot colder over UK and northern Europe in general mid Jan looking at the EC32 week 3 - 4 850mb temp anomalies too on the control, looking at -5 to -8C temp departures. Even the EC32 mean comes out average in the south  to slightly below far north of the U.K. I feel a bit desperate looking for cold at that range, but only thing positive atm!

[MPG]

[January Snowstorm]

8 hours ago, mountain shadow said:

I read your post before looking at the ecm and was excited that a change was on the way and well ermm i have no idea what you are talking about. There is no change of pattern advertised in its ops run.

 

As I said last night I was happy with ECM at 192. Am even more happy with this mornings run.

Christmas day is not sorted yet and a slight nudge would put us in the freezer esp for your location

[Mucka]

Well this is different.

 

Almost certainly will be an outlier within its own ensembles but there were 2 or 3 colder members last night that must have shown something similar.

It would be great to see some support in the latest set and for it to be repeated this evening but looks like a long shot at at the moment.

 

 

[IDO]

As expected the overblown Scandi Ridg/HP continues to be downplayed on the GFS. The op and control are now making very little of that wave as they continue to ignore the ECM's interpretation of the current signal in the Pacific, the GFS does not really go with the MJO phase 6 or 7. The GEFS at D16 offer very little to get excited about and similar pattern as the last two months but with the PJ slightly further south and maybe a slightly flatter jet:

     CFS w3+w4:            AO: 

CFS weeklies updated again show no pattern change till mid Jan at least, with just variations on a locked in pattern^^^ AO looks like taking a dip for a few days before climbing up again^^^

Looking through the GFS op for the next 16 days and the uppers are above average for about 13 days with very brief anomalous colder uppers that coming from the NW are washed out. ECM keener on a more even split after D5 but the ECM op has been up and down lately with its handling of the more meridional flow. Cannot rule it out but D8-10 ECM charts mixed with amplitude equals model entropy.

Compare the ECM d10 to the GEM, over 12c difference in uppers!!!

  

 

D10 temps anomalies from GFS :        https://twitter.com/adamksimkowski/status/677510643944067076

Which model has handled the non-MJO signal and if ECM is wrong then it is hard to take its FI output with too much credence. Not willing to side either way just yet so again more runs needed.

 

Edited December 18, 2015 by IDO

[Liam J]

Unfortunately the ECM monthly not looking as good on the overnight update with a continuation of the Euro high, winds from the S/SE at the turn of the month, then links with the Azores high bringing SW'ly winds. By the 7th Jan 1044mb high centred over Germany leaving the UK in a S'ly flow, always more unsettled towards the N/NW of the country. Into the second week the high gets flattened out turning more disturbed and zonal with depressions tracking ever further south bringing frequent blasts of PM air and also some northerly outbreaks at times. The run ends with a potent northerly blast with -10c 850's not far away from Scotland and the -5c line nearly touching Spain, the snow charts showing most of the UK having a covering of snow by mid month!  

[Frosty.]

The Gfs 00z op is a nightmare run for coldies, especially across england and wales with temperatures frequently in the 13-15 celsius range with s'ly / sw'ly winds dominating. Yesterday it reached 17c in oxford and that figure looks like being reached again tomorrow, maybe east yorkshire most favoured but widely up to 15 c tomorrow, sunday looks fresher, only reaching 14c in the south...don't laugh...and then very mild again next week which is great news for the daffodils!

[IDO]

IF just tweeted: https://twitter.com/fergieweather/status/677763147818774528

This ties in with the CFS. Much of the same but cooler, which TBH was easy to predict bearing in mind the record breaking November & December mildness. Still positive anomalous T850s for the rest of December according to GFS:

No surprise the ECM op has no support from its mean, the latter keeps with the consistent GFS mean for the last few days, with corresponding mild uppers: 

d10 ecm means:       GEM: 

GEM also on the same pattern. The strat remains our main hope for Feb/March.

Edited December 18, 2015 by IDO

[MP-R]

2 minutes ago, IDO said:

IF just tweeted: https://twitter.com/fergieweather/status/677763147818774528

This ties in with the CFS. Much of the same but cooler, which TBH was easy to predict bearing in mind the record breaking November & December mildness. Still positive anomalous T850s for the rest of December according to GFS:

No surprise the ECM op has no support from its mean, the latter keeps with the consistent GFS mean for the last few days, with corresponding mild uppers: 

d10 ecm means:       GEM: 

GEM also on the same pattern. The strat remains our main hope for Feb/March.

Ian's tweet re a change to more W/NW is certainly how I imagine winters to normally go, i.e. starting southwesterly and becoming more northwesterly as the season wears on; it's just happening a month later this winter. I do wonder, though, how a more northwesterly airstream is possible if the current Euro high doesn't budge - I'd quite like to see some consistency in the models before guessing what will happen after Christmas as they've shown anything from a Sceuro High, to continuation of southwesterlies, to a cold UK high to polar northwesterlies. 

One thing that does stand out in the models, however, is that it's highly likely we are shortly coming to an end of this record mildness with temperatures returning to at least average, if not slightly below depending on setup.

[legritter]

On 12/12/2015 at 10:27 AM, knocker said:

 

Morning all ,i,m feeling a lot more optimistic today regards a fair chance of some colder weather hopefully being modelled by todays charts in the further outlook .

But GFS still wild swings on every run ,Ecm interesting  bringing in colder 850 s in a slack flow so some people could see some wintry weather in the later christmas period .

just a gut feeling but the following days could see some eye candy as we start to see a slight change in weather type and the modells toy with different outcomes ,the great synoptic pattern of December 2010 started to fizzle out after christmas could our blowtorch current spell do the same, cheers all  I raise a glass to those prospects .

[Glacier Point]

Both EC and CFS week 3 - 4 outlooks suggest the core of tropical forcing shifting towards the central and eastern Pacific (equivalent MJO phases 7-8-1). That's Western Hemisphere. EC is less coherent, although would expect the (El Nino) low frequency signal to produce a slightly more coherent signal (aka CFS) nearer the time. That's very similar to September and October this year although the seasonal wavelengths will be different this time round. This doesn't look to me to damage angular momentum too much, so expected high angular momentum base state expected to persist well into January. That's a nod towards modelled pattern for weeks 3 and 4 with NW flow developing with scope for periodic northerly flow given the development of storm tracks across the Mississippi Valley towards NE Canada.

Source: http://monitor.cicsnc.org/mjo/current/v2/

Before that though, plenty more warmth to get through and solid agreement from EC EPS and GEFS for strong anomalous sceuro heights in the day 8-15 period. Strat will be interesting to keep tabs on period 10th January onwards.

Edited December 18, 2015 by Glacier Point

[Hocus Pocus]

Would that be a continuation of the present theme albeit less anomalous warmth and more in the way of PM incursions for the first two thirds of January at least GP?

[Frosty.]

The Gfs 6z by way of an apology for the very mild mushy 00z,  briefly shows a little love heart in mid atlantic  but again this run shows pulses of very mild air pushing n / ne across the uk next week with temps in the southern half of the uk in the 13-15 celsius range at times during christmas week, a bit more seasonal further north...however, it does cool down considerably on the 26th / 27th with slight night frosts, especially further north before it turns much milder again but the run ends with another love heart apology.

[bluearmy]

Interesting to see the amplified ridges beginning to send pockets of high heights into the arctic

keep watching this as if it persists, could force some changes to the jet profile

 

 

[Frosty.]

A record breakingly warm night tonight, becoming warmer as the night goes on with 14 / 15 celsius minimum, more like July than december!!!!!...time for a drink to numb the pain!

[nick sussex]

Nice to see the ECM entering the festive spirit. Say this quietly but its T192hrs could produce some snow on the north/nw flank of that shortwave which runs ne!

Of course at this range very low confidence but its not impossible that some areas in the north of the UK could have some snow late Christmas and into Boxing Day.

The ECM after this develops a lobe of high pressure to the north and amplifies the troughing to the west. This really is the key because the downstream response to a more amplified troughing is high pressure developing to its ne/east.

At this range impossible to predict how amplified any troughing would be so a lot of uncertainty because of this. The increase in amplitude of the pattern over the Pacific is a factor and also exactly what happens with the MJO.

The odds probably still favour a close but no cigar scenario but because of the MJO and strengthening signal to increase the amplification in the Pacific there might be a window of opportunity before the upstream pattern flattens again.

[Nick L]

5 minutes ago, nick sussex said:

Nice to see the ECM entering the festive spirit. Say this quietly but its T192hrs could produce some snow on the north/nw flank of that shortwave which runs ne!

Just for a bit of fun ...

 

 

Edited December 18, 2015 by Nick L

[nick sussex]

2 minutes ago, Nick L said:

Just for a bit of fun ...

 

 

Judging by that  it looks like the ECM develops that snow ne/sw so as the shortwave runs ene the colder undercut results in that snow. I don't want to cause undue expectations because its far out but given we've had so little wintry interest to talk about I might run to the top of the nearest hill and do a Julie Andrews! lol

The ECM of course is the best of a generally underwhelming bunch although the GFS 06hrs run has moved a little way towards it.

 

[Nick L]

Just now, nick sussex said:

Judging by that  it looks like the ECM develops that snow ne/sw so as the shortwave runs ene the colder undercut results in that snow. I don't want to cause undue expectations because its far out but given we've had so little wintry interest to talk about I might run to the top of the nearest hill and do a Julie Andrews! lol

The ECM of course is the best of a generally underwhelming bunch although the GFS 06hrs run has moved a little way towards it.

 

Yep, on that run there's a lot of heavy precip over England and Wales on Boxing Day, 850 Theta-W temps down to 0-1c over Wales with sub-zero dew points, with winds potentially light enough for evaporative cooling too.

Says a lot that the best we can find is a marginal snow event for mostly high ground 8 days out, and it's still better than what we've been seeing recently. Having said that, the previous EC had a pretty cold outlook around Boxing Day, although with the Atlantic ready to steamroll through afterwards.