Model output discussion - Into 2021

[BARRY]

3 minutes ago, iceman1991 said:

So sound like read through  the comments us southerners all will be having is rain and more rain like mid term mettoffice but anything above m4 be in luck ? 

All this talk of snow but like you it's rain and more rain

 

[stodge]

Evening all

The first day of 2021 in lowland East London was bleak and still - maximum at 3c so below average but tonight we've had drizzle. That's what happens with slack airflows in winter.

The output last evening was very strong for cold fans into FI with the notable exception of ECM which did suggest a milder evolution by T+240. Let's see where we are this evening.

12Z GEM: T+120 takes us to Wednesday next week. Heights over Scandinavia from a ridge from the Russian HP and heights extending south-east into the Atlantic from Greenland. The remants of the current trough over Poland and a new LP developing to the east of Iceland. The British Isles has a slack ENE'ly flow for southern areas and calm conditions further north with a light WNW'ly flow for northern areas. The lowest 850s across the south with a hint of something less cold further north and west. By T+180 the Icelandic LP has moved SE but has filled and phased with the trough over Poland while a new LP has formed and deepened over Iceland. Heights remain in the Atlantic with a broadly NW'ly flow over the British Isles. Uppers at -8 for most so still cold. From T+180 the new Icelandic LP slips SE down the North Sea and into Europe where it forms a complex trough through the central and eastern Mediterranean. Heights develop over Iceland and northern Scandinavia and the British Isles is covered by a slack E'ly flow by T+240.  Perhaps a brief less cold interlude but uppers by T+240 are again at -8 so still cold and colder air out to the east. 

12Z GFS OP - a solid enough evolution for cold fans from GEM. On then to the American OP and at T+120 the British Isles is in a col with LP over northern Germany and moving south from the east of Iceland while heights remain in the Atlantic and over Scandinavia. Uppers over the British Isles remain at minus 8 by T+120. The LP to the north is a fairly shallow feature and quickly phases with and fills into the European trough but by T+180 a new and more vigorous feature has moved down from Iceland and is close to northern Scotland with a WNW'ly flow over northern and western Britain while calm conditions prevail further south. Uppers remain at -4 to -8 with a new cold feed coming down with the new LP. The LP moves down through the British Isles and by T+240 is over southern France. Heights build from the Azores HP north east to the west of the British isles with perhaps a ridge to Scandinavia (we'll see) while small areas of LP move to the north of Iceland.  Heights over the British Isles remain at -4 to -8, lowest in the south under a residual NE'ly flow. Moving further into FI, the Azores HP topples into France and Iberia and Atlantic air quickly moves round the top re-introducing milder air by mid-month. At the end of FOI, a new trough digs into northern Scandinavia but it's a more mobile pattern with a brief ridge of HP to the west of the British Isles and a new LP developing to the south of Greenland. It's milder through into FI and I note the main lobe of the PV is moving back west across Siberia to be over Scandinavia by T+384.

12Z Parallel - a disappointing evolution for cold fans from the OP going into FI (an outlier perhaps?) but let's see what the Parallel has to offer. No great surprises from the T+120 if I'm being honest. Uppers at -4 to -8 generally. Moving on, the LP to the east of Iceland sinks south through the west of the British Isles and phases with the Atlantic trough which has been shunted far to the south over Iberia and North Africa. By T+180 the complex trough has centres over Biscay and the Balearics with heights over Iceland and Greenland and this means an E'ly airflow for the British Isles. Perhaps a slight modification of the cold over the British Isles but colder air is again heading towards our shores from the east. From there, the European LP migrates east and phases with a new deep LP over northern Scandinavia. There's a new LP just to the east of the Azores and a weak ridge in the Atlantic. The airflow over the British Isles is a slack N'ly by T+240 and the uppers have moderated to -4 generally by this time. Moving further into FI and it's a tale of LP encroaching on the British Isles from both north and south. From the north it's a tale of the new Scandinavian LP moving west and spawning a new centre to the south-west of Iceland. The airflow is from a W'ly direction by T+312. This has brought less cold air into the south but it's still chilly further north at this time. By the end of FI the Atlantic is back in charge with strong heights over Iberia and a very mild SSW'ly flow. However, cold PM air isn't far away to the east by T+384 and overall the mildest air is confined to the far south.

12Z ECM - more evidence of the GFS trying to call time on the cold pattern in FI but it's still FI at this time and we'll need to see it come within at least T+240 which it hasn't yet. Now, for ECM which perhaps picked up on a change to the pattern last evening. T+120 contains few surprises as you might expect.  The first LP to the east of Iceland is pushed out of the way by the Atlantic HP but by T+192 a new more vigorous LP has developed to the east of Iceland and is attempting to phase with the residual European trough which is centred over the southern French coast. Uppers over the British Isles remain at -4 to -8 with a new push of colder air from the north west. From there, we get a very different evolution with a small but vigorous LP over Cornwall by T+240 - I can only surmise this is the interaction of the two troughs and this LP is part of a large and complex trough over northern Europe with a new Atlantic LP negatively aligned to the west and residual heights extending from Greenland south. The air mass over the British Isles at T+216 is very cold but the new LP introduces significantly milder air into southern and western areas by T+240 but it's still cold for northern parts and I'd be surprised were plenty of snow not to come from that feature for the luckier northern and higher areas.

Looking elsewhere, 12Z Control brings back the Atlantic by T+228 but by the end of FI the pattern is negatively aligned with colder air back over northern and eastern parts.

As for the 10 HPA, 12Z Control has shredded the vortex by T+384, it's not much better on the 12Z OP by the same time. 12Z Parallel has raised the 10 HPA temperature to -56 at its lowest (unprecedented for mid January in my experience).

Conclusion: there's a growing signal from GFS to end the cold pattern from the west just before mid month though the extent to which the ongoing destruction of the PV is impacting on medium range modelling is one for others to debate. Most of the models keep us cold or very cold up to T+240 and one of two of the proposed breakdowns look very snowy but I suspect the modelling into FI reflects some real issues as to how to simulate a rapid downwelling of an SSW this early in the winter. 

[Eskimo]

2 minutes ago, BARRY said:

All this talk of snow but like you it's rain and more rain

 

I would expect so in a place like Devon! Central areas and the north are always far more favoured than the SW peninsula. 

[sebastiaan1973]

The control flattens the pattern.

For the control and other members ->

Model charts for Europe and Africa (Mean Sea Level Pressure) | ECMWF IFS HRES (10 days)

METEOLOGIX.COM

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ECMWF IFS HRES (10 days) - Current forecast valid for 01/09/2021, 07:00am of parameter "Mean Sea Level Pressure", model chart for map "Europe and Africa"

 

[Frosty.]

That’s a pretty cold ECM 12z ensemble mean tonight, it suggests entrenched cold, no sign of anything mild and I’m sure some of us will see snow during the next 10 days..+ ️ 

Edited January 1, 2021 by Jon Snow

[Ali1977]

Low minimums at the end of the ECM, not saying it’s correct but some cold nights (double digits) certainly possible across any snow fields. 

[Man With Beard]

17 minutes ago, northwestsnow said:

Could you post them ?

I like the graph forms, thats really cold for Manchester  and would suggest maxes of 1 or just less locally ...brrrrrrrr...

ECMWF 14-day ensemble weather forecast for Manchester Piccadilly Gardens Bus Station

WEATHER.US

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Manchester Piccadilly Gardens Bus Station, England, United Kingdom - The ideal weather forecast for the next 14 days. See the results of all 50 ensemble members of the ECMWF model in...

Goes below 2C (mean) after Tuesday

Edited January 1, 2021 by Man With Beard

[Allseasons-Si]

Evening all and Happy New Year

long post coming up

here is my usual round up of this evenings models/anomalies/graph's and charts:-

and to be honest not much has changed with the overall pattern from previous

here are the latest from EPS at day ten still showing that huge blocking height's W Greenland and still linking up with the Urals heights with a massive 971mb low NE Pacific/Alaska and trough SE of the UK,temps getting colder over Scandinavia too

the day ten means from ECM/gefs 500mb,850's and height anomalies still painting a similar picture as previously with again height's into Greenland with trough N/NE of the UK with below height's SE UK 

London ens,a cold week to ten days coming up as you all know but a scatter at the end(as they always do),there is still a lot to be resolved regarding this trough dropping down from the north at 120>

the NAO/AO still has no fuel in the tank,good,no one fill it ha! ha!

and looking at the De-built ECM ens we have our NE'ly nailed on now but considerable scatter after that thanks' to not knowing how this trough will behave from the north

the EPS tactile show the blocking getting further north of the UK as can be seen with the latest clusters 192>240/264>360, 

enjoy the rest of your evening and weekend gang,then it's back to work next week(can't wait)lol

and then next week it turns colder so some more snow opportunities about no doubt and you never know that we could be looking at a good dumping on snow around the corner 

P.S,as for the PPN charts,...FORGET IT,as snow is very! very! very!,....(yes i could go on) hard to predict even within 24hrs,so sit tight peeps and whatch it all unfold,...GOOD LUCK!

Edit:just read @Catacol's post,great post mate and that weatherbomb over the NE Pac surely will pack a punch and perturb more problems to the already trop pv. 

 

 

 

 

 

 

Edited January 1, 2021 by Allseasons-si

[iceman1991]

15 minutes ago, BARRY said:

All this talk of snow but like you it's rain and more rain

 

Yeah of your up north not down south look

[sebastiaan1973]

ECMWF runs the IFS in several configurations. The highest resolution "HRES" configuration is run every twelve hours out to ten days with a horizontal resolution of 9 km using 137 layers in the vertical.[3] The 51-member ensemble system "ENS" is also run every twelve hours out to 15 days with a horizontal resolution of 18 km and 91 layers in the vertical. The ECMWF also runs a coarser version of the IFS out 45 days; this version is run weekly, with output in five-day intervals. There is also a version that runs out one year. All model versions except HRES are coupled to the ocean model NEMO.

 

-> Perhaps the better -read more- vertical layers of the EC oper are in this process an important advantage. The ENS has around 40 vertical layers less.

[Tim Bland]

22 minutes ago, BARRY said:

All this talk of snow but like you it's rain and more rain

 

Compare current uppers / dew points to the time frames people are discussing snow...

[Bricriu]

2 hours ago, radiohead said:

The agony and the ecstasy....

Ecstasy for me. If i could  bank a chart it would be this one. I know it's not going to happen, but it's nice to dream!

[AdrianHull]

2 hours ago, radiohead said:

The agony and the ecstasy....

The agony of a precipitation chart 11 days away... More chance of winning the lottery... We need to reel it in a bit! 

Edited January 1, 2021 by AdrianHull

[northwestsnow]

Icon looks in decent nick at 120 ...

 

Edited January 1, 2021 by northwestsnow

[Snow Queen one]

2 minutes ago, AdrianHull said:

The agony of a precipitation chart 11 days away... More chance of winning the lottery... We need to reel it in a bit! 

Not for me lol all I get is rain from those charts not interested in that

[sheikhy]

18z delayed again

[Eskimo]

Just now, sheikhy said:

18z delayed again

Must be booting up Bartlett mode. 

[ICE COLD]

3 minutes ago, iceman1991 said:

No need be sarcastic all abroad 

here’s one he’s just posted 

 

Originally Posted by: Brian Gaze 

ECM 12z op also brings milder air back into the south. Decent snow event along the boundary zone - very probably northern half of the UK - remains a distinct possibility IMO.

 

 

1. It’s day ten mate 

2. It could happen but the cold will come back in days 11 and 12 +

3. it could happen and stay milder 

4. it won’t happen like that so don’t worry bout it . We’re in a great place pal . 

[Matt H]

5 minutes ago, Eskimo said:

Must be booting up Bartlett mode. 

Please spare us from having this debate again.

Edited January 1, 2021 by Frosty Winter

[Man With Beard]

11 minutes ago, iceman1991 said:

No need be sarcastic all abroad 

here’s one he’s just posted 

 

Originally Posted by: Brian Gaze 

ECM 12z op also brings milder air back into the south. Decent snow event along the boundary zone - very probably northern half of the UK - remains a distinct possibility IMO.

 

 

The Met Office got a Channel Low wrong at T36 earlier this week. That puts into context how seriously we should take the positioning of a low at T240. I agree with Brian Gaze that it's plausible - along with about 50 other plausible outcomes for T240!!!

[Scott Ingham]

14 minutes ago, iceman1991 said:

No need be sarcastic all abroad 

here’s one he’s just posted 

 

Originally Posted by: Brian Gaze 

ECM 12z op also brings milder air back into the south. Decent snow event along the boundary zone - very probably northern half of the UK - remains a distinct possibility IMO.

 

 

Good outlook for me in Yorkshire though

[Allseasons-Si]

Talking about PPN within 24 hrs the latest ICON shows some snow pushing down from NE England down towards S Wales from tomorrow morning.

[iceman1991]

6 minutes ago, ICE COLD said:

1. It’s day ten mate 

2. It could happen but the cold will come back in days 11 and 12 +

3. it could happen and stay milder 

4. it won’t happen like that so don’t worry bout it . We’re in a great place pal . 

Sorry all what’s going on at the moment would be nice for all of us to have a nice cold wintry spell with lots of snow because we all deserve it it’s just frustrating will just have to sit back and wait and see the outcome

[Djdazzle]

I know this is the model discussion thread, but this over-analysis and stress about snow on a 240 chart is laughable.

[Matt H]

16 minutes ago, iceman1991 said:

No need be sarcastic all abroad 

here’s one he’s just posted 

 

Originally Posted by: Brian Gaze 

ECM 12z op also brings milder air back into the south. Decent snow event along the boundary zone - very probably northern half of the UK - remains a distinct possibility IMO.

 

 

I personally think that way too much thought is being put into one day 10 chart that’s going to be different tomorrow anyway. The big picture still looks good for cold going forward and that’s the most important thing.