Model Output Discussion 29th December - Into mid-Winter.

[bluearmy]

21 minutes ago, feb1991blizzard said:

Not sure how anybody can say that the question raised 2 days ago is still the same now, zonal actually looking far more likely than Scandinavian blocking, personally I have no reason to disbelieve the Met office and think it will be dry and fairly cold into the 10-15 day range with milder and wetter in Scotland, this based on the ECM ens total collapse over a few runs.

Total collapse of what? Pattern pretty consistent but of course slightly flatter and slightly further east but well within tolerance of what can be expected over a couple days output. 

The extended eps maintain the theme though the centre of the trough more sceuro than euro and the high anomolies more wnw than nw. I suspect a big spread of clusters and Matt has confirmed that

the Dutch wind direction chart may look very spaghetti like shortly 

[feb1991blizzard]

Just now, bluearmy said:

Total collapse of what? Pattern pretty consistent but of course slightly flatter and slightly further east but well within tolerance of what can be expected over a couple days output. 

The extended eps maintain the theme though the centre of the trough more sceuro than euro and the high anomolies more wnw than nw. I suspect a big spread of clusters and Matt has confirmed that

the Dutch wind direction chart may look very spaghetti like shortly 

BA the mean ridge was ridging much much further North about 48 hours ago.

[knocker]

There is not a lot to say about this evening's anomalies that hasn't been said over the last couple of days In particular I'm keeping in mind the NOAA forecaster summation yesterday evening, unfortunately being the weekend tonight's is merely automated, which was a very high degree of confidence out to day 14. That is not usual.

Anyway a quick run down.

Sharp Aleutian ridging with a lively Canadian vortex with a cold trough over NW North America dragging down some very cold Arctic air. Low anomalies in general over N. America with the other significant trough in eastern Europe. Downstream we continue to have an Atlantic wave driven from upstream with amplification of the high pressure to the west of the UK with the ubiquitous upper low pressure area to the south continuing to play a significant role. There is no complete agreement still on the position of the ridge but it does appear to be edging east so still a cold dry outlook very much on the cards albeit the det runs will need to sort out the details.

No huge change in the 10-15 period except there are signs at the end of losing the Aleutian ridge to be replaced with a trough from the vortex. Whether and what changes this may herald downstream is yet to be determined. Meanwhile we are still looking at positive anomalies in the eastern Atlantic with ridging adjacent, or over, the UK. so at this stage the dry and cold weather looks set to be around for 14 days on this evidence but the det models will need to sort out the detail vis the ridge as this will ascertain how susceptible the UK will be to incursions of colder air from the north west

[feb1991blizzard]

3 minutes ago, bluearmy said:

Total collapse of what? Pattern pretty consistent but of course slightly flatter and slightly further east but well within tolerance of what can be expected over a couple days output. 

The extended eps maintain the theme though the centre of the trough more sceuro than euro and the high anomolies more wnw than nw. I suspect a big spread of clusters and Matt has confirmed that

the Dutch wind direction chart may look very spaghetti like shortly 

Surely you must accept that the last 48 hours of runs have meant that an Easterly is much much less likely than it was????

[swilliam]

Huge spread on the dutch ensemble at D15 as expected ranging from -10C to + 7 (nothing that could be described as mild then).  Mean about 2/3 C and a reasonable cold cluster as well so still all to play for IMO.

[phil nw.]

1 minute ago, feb1991blizzard said:

Surely you must accept that the last 48 hours of runs have meant that an Easterly is much much less likely than it was????

If i may come in on this on blizzard.The easterly as i am sure you know was never a favoured option.Yes it showed in later frames of the odd gfs op run but never close enough to take seriously and had only minority support in the ens. 

The trend for week 2 is cold and dry with a high nearby.There has been suggestions in some of the clusters for a brief second northerly next weekend before the high moved in again but never more than that really.

I do think the very snowy couple of gfs op runs the other day have raised expectations beyond the reality showing in the ensembles and clusters.

Having said all that with the current NH profile of Pacific and Atlantic ridging the future prospects for something better for coldies beyond the next few days is still there whereas it wouldn't be in a flat zonal NH pattern.

 

[Jammydodger]

Huge spread Dutch ens, huge spread ec ens, this time last year it was raining, warmish with no end in sight..2017 = Cold?,dry?,snowy?,icy?, who knows not even the mighty Met..

No sign of wind and rain with warm Temps first few weeks 2017..

Everyone have a nice chilled beer and see what 2017 brings HNY

Edited December 31, 2016 by Jammydodger

[legritter]

Evening gang ,as long as we can hopefully keep some good cold to our east and far n east I am hopefully of something more wintry turning up ,I know it's day 9 and ten on ecm but that top right corner on the chart could become our friend ,if that high over n West Russia area can set up right it could lead us into what we desire ,seen it before myself and seen many historical charts ,just a thought ,is this what Exeter are seeing ,anyhow 94 yr old mother in law needs tucking in ,then I will pour out a STELLA  I wish all my Fellow posters and NW  team all the Best for 2017 ,best weather forum in the northern hemisphere by far ,cheers 

[bobbydog]

Easterly, westerly, whatever... it's new years eve. Tomorrow is a new year. We've seen every weather synoptic possible shown in the models over the past month or so. We've got one more GFS run left of 2016. It might not show what we want but there are plenty more left. Let's just enjoy what's left of this year and hope the new year brings us a winter wonderland before winter ends. Just keep the enthusiasm going despite what the models might show and we could eventually see a few flakes.... or more....!

Happy New year to everyone on Netweather. 

Rob.

[feb1991blizzard]

7 minutes ago, phil nw. said:

If i may come in on this on blizzard.The easterly as i am sure you know was never a favoured option.Yes it showed in later frames of the odd gfs op run but never close enough to take seriously and had only minority support in the ens. 

The trend for week 2 is cold and dry with a high nearby.There has been suggestions in some of the clusters for a brief second northerly next weekend before the high moved in again but never more than that really.

I do think the very snowy couple of gfs op runs the other day have raised expectations beyond the reality showing in the ensembles and clusters.

Having said all that with the current NH profile of Pacific and Atlantic ridging the future prospects for something better for coldies beyond the next few days is still there whereas it wouldn't be in a flat zonal NH pattern.

 

Yes, absolutely but about 5/6 probably more GEFS members were showing it, now hardly any, so you cannot say that prospects for snowy cold have not downgraded over 48 hours very significantly - btw iMO the second N flow was very well supported.

[BARRY]

Happy new year and another rollercoster year of model watching.

[karlos1983]

Just now, bobbydog said:

Easterly, westerly, whatever... it's new years eve. Tomorrow is a new year. We've seen every weather synoptic possible shown in the models over the past month or so. We've got one more GFS run left of 2016. It might not show what we want but there are plenty more left. Let's just enjoy what's left of this year and hope the new year brings us a winter wonderland before winter ends. Just keep the enthusiasm going despite what the models might show and we could eventually see a few flakes.... or more....!

Happy New year to everyone on Netweather. 

Rob.

Well said Rob, 

i want a bitter winter as much as the next, but one thing this year has thought me, is your health is your wealth, big time!!

enjoy life, smile at people and treat others as you'd expect to be treated. 

Happy New Year everyone 

may it be cold!! 

[Methuselah]

8 minutes ago, feb1991blizzard said:

Yes, absolutely but about 5/6 probably more GEFS members were showing it, now hardly any, so you cannot say that prospects for snowy cold have not downgraded over 48 hours very significantly - btw iMO the second N flow was very well supported.

If it's going to happen then it will, if it's not then it won't; the weather doesn't care one jot about what the models are showing...Ergo, there's no need for pessimism...

PS: May all your New Year weather-wishes come true!

Edited December 31, 2016 by Ed Stone

[Summer Sun]

In case anyone hasn't noticed GFS P is not available today

[nick sussex]

Just looking at the NCEP monthly forecast for the USA as to what we should expect upstream. They don't think the MJO is going to have a significant effect on the pattern over there and that's not a surprise given its low amplitude and it shows no signs of leaving the COD.

They're uncertain about the prospects for the second half of January.

I think we're currently in a very stuck pattern, the reluctance to drop heights over southern Europe is the big issue because without that its very hard to transport that much colder air to the e/ne westwards.

If you're trying to look at positives there won't be a lack of cold air to draw on if we see a bit more amplification upstream which could help to draw the Scandi troughing further west/sw.

Realistically theres no chance of any blocking over Greenland in the next two weeks, any interest has to come from a Scandi high as that's the only route that could develop within the current NH set up.

Unless we see a lot more amplification showing up within T144hrs then it looks like if theres to be an opportunity it will develop later with a shortwave cutting se'wards.

What tends to happen in this set up is something along the lines of the ECM T240hrs, my paint jobs are back ! so I've done  a quick one to show how the ECM could tip that way.

What you're looking for is a shortwave to develop around where the green arrow is and head se but you need a more amplified upstream troughing shown in red. The high ahead of the troughing in purple then topples ne'wards joining forces with the Scandi high. The low heights to the north head ne, the shortwave helps to expand those low heights over se Europe and then you get a chance to get the colder air westwards. The issue for the UK is always whether the cold advection makes a direct hit or whether it stays just across the Channel. But at least with the trigger shortwave you have a decent chance of getting some of that deeper cold.

At the moment the more boring cold and dry scenario is favoured but it wouldn't take a miracle to draw some of that cold westwards but it seems as if getting over the final hurdle so far this winter has been a monumental task!

 

Edited December 31, 2016 by nick sussex

[bluearmy]

47 minutes ago, feb1991blizzard said:

Surely you must accept that the last 48 hours of runs have meant that an Easterly is much much less likely than it was????

I was simply questioning your assertion that the eps had  completely collapsed - these don't show that (sat 7th last three 12z runs)

 

  

[bluearmy]

Btw, the more cyclonic nature of the extended eps via a sceuro trough rather than centred a little further south is well illustrated by more less cold de bilt members due to more onshore flow members. of course that does mean less chance of a scandi ridge but I suspect the cluster showing that isn't much changed from the 00z run. 

[Djdazzle]

GFS 18z rolling out - the last run of 2016. Hoping 2016 goes out with a bang!

[lorenzo]

Happy New Year All - thought I would throw some strat plots for lower levels to add to the current divergence among the models, controls and ens.

When looking at ECM det and also ECM Ens - like to keep an eye on the atmosphere above.. given MJO evolutions not in the mix for around 8 days.

The 100 hPa pattern, ridging and also weakened nature of vortex looking fun at this juncture - incidentally a time stamp right on the crux of much discussion the last couple of days. 

Correlate the 475K with Meteociel NH View on 850 Vent Anoms, the flow is visible. Poised at day 10 and more than one set of atmospheric dice about to roll.

PS some insightful data on twitter tonight pointed to the NAO dataset for those that follow that, huge Bz interest across  Dec

[radiohead]

Stronger low off Newfoundland on the 18Z.

[fromey]

3 minutes ago, lorenzo said:

Happy New Year All - thought I would throw some strat plots for lower levels to add to the current divergence among the models, controls and ens.

When looking at ECM det and also ECM Ens - like to keep an eye on the atmosphere above.. given MJO evolutions not in the mix for around 8 days.

The 100 hPa pattern, ridging and also weakened nature of vortex looking fun at this juncture - incidentally a time stamp right on the crux of much discussion the last couple of days. 

Correlate the 475K with Meteociel NH View on 850 Vent Anoms, the flow is visible. Poised at day 10 and more than one set of atmospheric dice about to roll.

PS some insightful data on twitter tonight pointed to the NAO dataset for those that follow that, huge Bz interest across  Dec

who posted on twitter tonight??

[chrisbell-nottheweatherman]

3 minutes ago, lorenzo said:

Happy New Year All...

As it's quiet in here at the moment, perhaps the moderators might permit me to request a slightly less technical explanation, please?

[chrisbell-nottheweatherman]

1 minute ago, radiohead said:

Stronger low off Newfoundland on the 18Z.

Would that sink the UK high and return us to a zonal Atlantic setup?

[Bristawl Si]

2 minutes ago, chrisbell-nottheweatherman said:

As it's quiet in here at the moment, perhaps the moderators might permit me to request a slightly less technical explanation, please?

I thought that as well 

[lorenzo]

1 December had a strong NAO signature image courtesy of Anthony Masiello on twitter.

2 Bz refers to solar influence on the NAO and whether increased activity expands the Hadley Cell vs other forcing ( eg MJO)

3 The strat plots show a distended vortex carved across the NH as a result of a 2k M Wave 1 forcing, the Pacific Block pushing the vortex, being met briefly by the Atlantic anomaly.

4 The 100 hPa pattern shows the avenue to support ridge development NW  > NNE and also the intrigue of the next evolution of the vortex energy shown in the 475K, around that time the MJO will be on 2-7 days for activity again.