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Model output discussion - into 2018


Paul

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Posted
  • Location: Abingdon - 55m ASL - Capital of The Central Southern England Corridor of Winter Convectionlessness
  • Weather Preferences: Winter: Snow>Freezing Fog; Summer: Sun>Daytime Storms
  • Location: Abingdon - 55m ASL - Capital of The Central Southern England Corridor of Winter Convectionlessness
54 minutes ago, karlos1983 said:

Getting a tad toasty up top, that would be some call from Chio if it plays out like this, I’m sure he said start of a warming event 20th Jan, hats off sir! :hi:

D6C1C793-82B2-45D6-A00F-5D3723F72E9C.thumb.png.ae57848159fdeef4e09050bc909936de.png

If I had £1 for every time GFS thought that was going to happen at T+384...

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
53 minutes ago, CreweCold said:

Quick Tropospheric Response

Jan 09 was unique in that it is one of the only upwelling events ever recorded. Essentially if you think of our December pattern and how the trop managed to slow zonal winds further up for a while, it was just more effective. Much like our own event though, after the initial plunge we saw the stratosphere cool (because the higher levels had not been completely decimated) and then by mid-Feb it was all over.

GEFS mean does suggest that zonal winds will be no higher than average by about the 20th though so with our kind trop this year, i'd think that even with no SSW we'll probably see a better pattern more consistently into February.

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Posted
  • Location: uxbridge middlesex(- also Bampton oxfordshire
  • Weather Preferences: blizzard conditions. ice days
  • Location: uxbridge middlesex(- also Bampton oxfordshire
8 minutes ago, snowray said:

True, but I'm just making a comparison nearer to home, if we had the plunge of cold air that the USA gets every years I can assure you that it would snow in the UK alright, even at below sea level. -20/-24c uppers around New York remember.

Its just that we would get a lot more in the way of snow events from cold zonality for example, and marginal events would be much less marginal if there was more higher ground, even 100m can make a big difference. Steve M has talked about this before, thats why he's moved to the Kent Alps at about 150m asl from where he lived before at sea level. 

Don't get my wrong, I'd much prefer the NYC style cold plunges and the PV sitting over us, but they are after all very rare in our neck of the woods, small Island surrounded be sea or whatever the scenario.

gfsna-0-6.png

gfsna-1-6.png

Even with these modified atlantic uppers; -8 the convective overtone would have snow @around 100 asl...

Quite a remarkable note...

As pm flow rarely deliver such minama!!

 

gfsnh-1-240.png

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Posted
  • Location: Stoke Gifford, nr Bristol, SGlos
  • Location: Stoke Gifford, nr Bristol, SGlos
19 minutes ago, Frost HoIIow said:

They can get tons of snow at sea level in New York City, and its a lot further south than the UK. Its where the UK is located thats the problem, not solely altitude.

I usually post in November about the gulf stream, little island next to the Atlantic, blah, blah - usually get a bit of stick for it - but those v simple thoughts manage my expectations almost every Winter.

Model output aint worth worrying about past 5/6 days into the future for our little set of islands. And as for trying to predict weeks or months down the line via LRFs, whether using teleconnections or otherwise just forget it.:D

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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
7 minutes ago, summer blizzard said:

Jan 09 was unique in that it is one of the only upwelling events ever recorded. Essentially if you think of our December pattern and how the trop managed to slow zonal winds further up for a while, it was just more effective. Much like our own event though, after the initial plunge we saw the stratosphere cool (because the higher levels had not been completely decimated) and then by mid-Feb it was all over.

GEFS mean does suggest that zonal winds will be no higher than average by about the 20th though so with our kind trop this year, i'd think that even with no SSW we'll probably see a better pattern more consistently into February.

2009 was a downwell event where the strat split from the top downwelled immediately - and it was the split of the vortex that ejected the energy westwards across the UK from the split vortex.

Run the animation in the following link

https://earthobservatory.nasa.gov/IOTD/view.php?id=36972

Upwell events I have seen so far have been early season through Greenland before the strat vortex has strengthened.

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Posted
  • Location: North East Hampshire
  • Location: North East Hampshire
24 minutes ago, The Enforcer said:

If I had £1 for every time GFS thought that was going to happen at T+384...

...and if I had a pound for every time people told me the strat forecasts are more reliable. Still never seem to come off though!

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Posted
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.

Some severe ground frosts for the Highlands over the weekend.

viewimage-39.thumb.png.6773c40017926d1fe50e19bc48375c4c.png

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

The Ecm 12z seems to be almost duplicating its 00z output with some milder conditions at times next week.:)

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Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
3 minutes ago, Johnp said:

...and if I had a pound for every time people told me the strat forecasts are more reliable. Still never seem to come off though!

The strat forecasts don't jump around at T+384 like the trop output, so in that respect they are. However, picking up the trop signal to create a warming depends upon the trop forecast - so we could say it's interlinked. The strength of any trop blocking precursors that are modeled vary and hence the strength of any strat warming varies - but it is definitely less volatile.

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Posted
  • Location: Lytchett Matravers - 301 ft ASL
  • Weather Preferences: Snowy Winters, Torrential Storm Summers
  • Location: Lytchett Matravers - 301 ft ASL

Naughty ECM, go and stand in the corner :nonono:

138F27DF-7438-48D0-8EE9-2578BDC250EF.thumb.jpeg.1106f94ad14587f035a289e222b3981e.jpeg

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Posted
  • Location: Home: Chingford, London (NE). Work: London (C)
  • Weather Preferences: Winter: cold and snowy. Summer: hot and sunny
  • Location: Home: Chingford, London (NE). Work: London (C)
1 hour ago, snowray said:

Thats the real reason we don't get much snow in the UK, Altitude, most places where people live are at or near sea level.

Not really. For our latitude we get very little snowfall. 

The makn reason is not altitude - as someone else pointed out, New York gets much more snowfall than us and is at sea level. New York is also on the western edge of a huge, relatively warm ocean. 

The UK is an island, our waters are warmed by the Gulf Stream, our prevailing wind is from the SW/W, and even when we get cold air from the NW/N/NE &E it is heavily modified compared to other areas of the globe at our latitude because it passes over relatively warm water. 

Its stating the obvious here, but places like Moscow, New York, Toronto, many parts of central and Eastern Europe etc are directly connected to the Artic by a continental landmass. 

The most “continental” part of the UK climatalogically is generally the SE due to its proximity and short sea track to Europe, and distance from the Atlantic. 

Therefore we will always struggle to get deep cold in the UK, particularly down south. So many things need to fall into place! 

ECH0-168.GIF.png

Edited by danm
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Posted
  • Location: Wirral, Merseyside
  • Weather Preferences: Snow & Thunderstorms
  • Location: Wirral, Merseyside

The ECM throws a nice warm blanket over the UK :bad:

ECH0-168.GIF.thumb.png.b00c056461c47ff8f6c15df4683063f3.png

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Posted
  • Location: Wildwood, Stafford 104m asl
  • Weather Preferences: obviously snow!
  • Location: Wildwood, Stafford 104m asl
1 minute ago, Frosty. said:

The Ecm 12z seems to be almost duplicating its 00z output with some milder conditions at times next week.:)

Ay, think I'll get my shorts out, not usually a fan of ECM at this range, an example too of earlier this week, but have a feeling this could be accurate ish

ECM1-168.GIF?05-0

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Posted
  • Location: Chisinau, Moldova.
  • Location: Chisinau, Moldova.
8 minutes ago, Frosty. said:

The Ecm 12z seems to be almost duplicating its 00z output with some milder conditions at times next week.:)

Congrats Frosty. I was wondering who would first discuss that which must not be discussed.

Edited by jvenge
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Posted
  • Weather Preferences: Cold and Snowy, Hot and Dry, Blizzard Conditions
  • Weather Preferences: Cold and Snowy, Hot and Dry, Blizzard Conditions
Just now, Day 10 said:

The ECM throws a nice warm blanket over the UK :bad:

ECH0-168.GIF.thumb.png.b00c056461c47ff8f6c15df4683063f3.png

Well my feet do get cold....

I'm waiting for the 240 for maybe a hint of change....

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Posted
  • Location: Rotherhithe, 5.8M ASL
  • Location: Rotherhithe, 5.8M ASL
1 minute ago, Frosty. said:

The Ecm 12z seems to be almost duplicating its 00z output with some milder conditions at times next week.:)

ECM is truly diabolical. Filth.

EAFCEF21-89D5-4E9F-8C1C-285BAA8A5DE2.thumb.gif.64f3fbe85d01d67df44248127738ddb2.gif  

Anywho Sunday some transient sleet/snow for the S looks quite possible before milder air / dew points poke in.

32F7BEB7-ECCC-4C69-9A9F-8BB453314B28.thumb.gif.eb3f5db5d44a8e421bd9c4227c3b73f8.gif

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Posted
  • Location: Hertfordshire
  • Location: Hertfordshire

I do not know what happened to the ECM op run this morning but all models (at least the big three) now showing the amplification that I forecast the models would soon start to latch onto due to strat forcing with wave 2 heights building from central northern Europe north. Whether anything meaningful (cold and wintry wise) comes of this amplification remains  to be seen but I would expect at the very least 3 or 4 days of cold, very cold weather to come between t144 and t300.

Just seen the ecm has gone off on one again. What has happened to that model. Dear oh dear.

Edited by comet
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Posted
  • Location: STEVENAGE, HERTS (100M ASL)
  • Location: STEVENAGE, HERTS (100M ASL)
2 hours ago, Steve Murr said:

@fat chad

 & Everyone

I am still basing my forecast on the below image with 2 caveats for expected change -

6A42BB2D-8D82-4093-AA63-4C974EB65DE5.thumb.png.044ae5215a8284ea1eb68673ab9fadf1.png

 

1) heights & cold pool ... > If you draw a big circle around Central Europe on that meteociel chart the height are 544-548 ( green ) with a cold pool around 0c to -4c

** History indicates that the GFS over estimates these heights by 4-8 dam sometimes even 12 dam which is another reason why it looked so tame V the euros-

assumjng The Easterly lands as predicted above then expect that Green to change to the first colour of blue with even a central pool of lower heights into the next layer of blue - so a forecast to drop from 544-548 to 536-540 ( core pool 532 dam) 

This will also signify a reduction of upper temps along a similar gradient so instead of 0 to -4c you get -2 to -8c

* Secondly the glow allignment is SEasterly - this can also be a GFS bias of the strength of the southern arm not being identified to sub T120

below is the T156 Jet chart from 06z

802C95F9-664C-4B24-95F6-25CE07DEF7E8.thumb.png.5640117d918525270524e0b9068935cc.png

look as we get nearer 120 & below for more of an Arc / n shape across Italy - more amplification- this will enhance the easterly allignment-

if you look at T54 that’s why the Easterly is getting sharper now because of the upwards flow

028FC24D-FBE6-4707-AC13-5F36B26757DA.thumb.png.97b738a6329d08d6b5e57cb08620db92.png

 

so these would Be my pointers to everyone looking in on the models looking for a more classical Easterly @168..

The forecast for this period (144-192) is my representation research & acknowledgment of bias - no one else’s.

 

thanks

S

 

Hmm... no signs of Steve’s classic Easterly at 168hrs on the models tonight, especially the ECM! Perhaps it will be as much of a dead duck as the easterly the models and many were touting for this weekend a week ago? 

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Posted
  • Location: West Sussex
  • Weather Preferences: Extreme cold & snow
  • Location: West Sussex
48 minutes ago, RAIN RAIN RAIN said:

12z ECM coming out soon, I'm sure we will see a complete turn around to a strong easterly. 

I think you well & truly jinxed it!

image.thumb.png.320a08215986620591004b8becb9354d.png

image.thumb.png.76cda94bb2bcbaf997d5932dc73149c0.png

:D:wallbash:

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Posted
  • Location: Waltham Abbey, West Essex 144ft a.s.l.
  • Weather Preferences: snow, thunderstorms
  • Location: Waltham Abbey, West Essex 144ft a.s.l.

Could be a mild outlier the as the 00z this morning. We will know by 8.30

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Posted
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield
  • Weather Preferences: Any Extreme
  • Location: Sheffield South Yorkshire 160M Powering the Sheffield Shield

ECM has back tracked rapidly and seems to be now more progressive than the GFS. ECM isn't always right and FI land is always fraught with danger which is what catches so many people out.

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

Amazingly I thought i was looking at the 00z Ecm again, some mild days next week which isn't in the script but will it be right?:D

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Posted
  • Location: Redbourn,Herts AL3. 122M ASL
  • Weather Preferences: Hot summers, Storms and epic cold snowy winters
  • Location: Redbourn,Herts AL3. 122M ASL
1 minute ago, Purga said:

I think you well & truly jinxed it!

image.thumb.png.320a08215986620591004b8becb9354d.png

image.thumb.png.76cda94bb2bcbaf997d5932dc73149c0.png

:D:wallbash:

You simply could not make it up...Unless you're the ecm...mind boggling. 

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Posted
  • Location: Crewe, Cheshire
  • Weather Preferences: Snow, storms and other extremes
  • Location: Crewe, Cheshire
20 hours ago, CreweCold said:

We're past the point of no return for the initial E'ly now I'd say. However, days 8+ are not sorted. You'd have to put the money on a visit from the Atlantic in some shape or another but I'm still not 100% sure of what form this will take...could be anything from a TM SW'ly, polar NW'ly or a transient continental undercut!

I think we have a full house on the models tonight after the ECM run....

 

Edited by CreweCold
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