scotland Scotland Regional Discussion - Autumn 2013

[blitzen]

Most winters I think Blitzen? That's what we get for living on the furthestmost tip of a small island sitting between a big sea and a huge ocean

 

[Buriedundersnow]

couple of little interesting things on the 18z which if further runs continued the theme could turn things a little more interesting shame its the PUB RUN though

[Buriedundersnow]

see if we could get a mix of the the ECM 12z atlantic and the GFS 18z America we could manage to develop something.

 

below is the ECM 12z 120hr and the GFS 18z 114hr so same time green circle is good bit and red cross is the bad bit.

 

ECM

 

 

the main point of interests are the retrogression of the high and the bit around Greenland with the trough looking ready to sink in the ECM which is the good part the bad part is what it does with the low pressure over America

 

GFS

 

 

the GFS is opposite we want the low pressure in this right as it develops it less and the atlantic to be wrong as it doesn't go for the retrogression of the high it did hint toward doing it but failed and looks worse around Greenland

 

now if we move on to the ECM 12z 144hr we can see due to the over developed low (red cross) which the GFS doesn't have it pushes the high further east and in turn pushes the trough that looked primed to sink along with it where as the high wouldn't be forced like that on the GFS due to the low pressure being down the east coast of America giving the trough a better chance to sink over us and the high pressure to continue to retrogress

 

 

now moving on to the GFS 18z 138hr so again same time frame i have put black lines to show where the high pressure and the trough were due to the retrogression and the trough located by Greenland the red arrow shows where the trough would go due to the high retrogressing shown with blue arrow which would open us up to some polar air and with the low pressure still working up the east coast of America could hopefully push the atlantic high toward Greenland and turn us seriously chilly

 

 

so what i am trying to say is ECM atlantic good and GFS America good and hopefully if i have explained right if we could get that mix of both the runs we could see something pretty good

Edited November 23, 2013 by Buriedundersnow

[NUT]

The fog has decended again

[blitzen]

Morning.   3c here and calm and I was expecting a frost!

 

Much improved GFS Op run this morning for coldies though given how dire yesterdays output was that isn't saying much.

Basically it has shifted the pattern West and we get a couple of glancing blows of Arctic air but it is not hard to see how something more significant could develop with a few tweaks.

 

GFS 00z day 8

 

 

and day 10

 

Copied from model thread.

 

1h

The GEM model is at it again. A very interesting pattern... http://www.wetterzentrale.de/pics/Rgem216

Matt Hugo on Twitter.

 

Question: GEM? is it German, Dutch, I can't remember.

Edited November 24, 2013 by Blitzen

[Hawesy]

Morning all,

 

Sunny spells again after 6 hours of sun yesterday and around 30 hours in the last week - not bad at all for November. Pity it's likely to be grey after tomorrow. + 3c.

 

The GEM model is Canadian, Blitzen.

[blitzen]

Canadian:

 

http://en.wikipedia.org/wiki/Global_Environmental_Multiscale_Model

Not far wrong then! Thanks Catch.

 

 

 

 

The GEM model is Canadian, Blitzen.

El thicko thanks you Hawesy

Edited November 24, 2013 by Blitzen

[Buriedundersnow]

ECM 00z on a big tease, heights into far side of the pole and towards Newfoundland seem to push everything south on our side. That's one way to get cold air to us, just shunt the whole PV

 

 

your missing the main thing the ECM is doing if you look at the day 10 chart on 850's from the last three runs it is slowly shunting the cold our way

 

[Buriedundersnow]

another thing to note from the London ensembles today is it looks like the ECM might be hooking on to a cold solution in the extended but still has a few toying with warmer things

 

Edited November 24, 2013 by Buriedundersnow

[NorthernRab]

Currently -2'C, patches of freezing fog throughout the glen, looking like a chilly night ahead!

[Norrance]

Sunny here all day again with the frost lingering in the shade. Currently 0.8C and falling. One more sunny and frosty day to come before the mild cloudy dross encroaches.

Blitzen. It was February 2012. SE Europe through to Italy had severe cold and deep snow. The cold briefly got to the SE of the UK.

Edited November 24, 2013 by Norrance

[Northernlights]

Dull damp non frosty start to the day but  cloud broke and afternoon sunny but temperature has fallen all afternoon to the point where there was a ground frost in the shade at 3.30pm.  Currently  clear and 1.0c

[Buriedundersnow]

your missing the main thing the ECM is doing if you look at the day 10 chart on 850's from the last three runs it is slowly shunting the cold our way

 

ECH0-240.gifECH0-240.gifECH0-240.gif

 

to add to the previous post here is the pressure charts at day 10 for the last three ECM runs

 

 

you can see out to our west it is trying hard to get the east coast of Canada sorted out and down the line could give us a cross polar flow if this continues if we see the trough move either the way of the yellow or orange arrows then we might see the high infiltrate Greenland shown by the black arrow

 

 

now with the GFS coming toward the ECM today it might be something to watch for in the days ahead

[blitzen]

I don't think I'll last the pace this year. I'm already model fatigued and it's only the 24th November!

[Highland Snow]

Nippy day in the Fair City. Minimum last night -2.9C, Maximum today +2.8C at 14.59, currently -0.4C/-1.2C (-1.5C/Hr) with a crystal clear starry sky so will get the Meade telescope out after Jupiter rises at 19.00.

[Buriedundersnow]

I don't think I'll last the pace this year. I'm already model fatigued and it's only the 24th November!

 

it is a bit tedious waiting for something to come in cold wise but remember the GFS was showing blocking around the 5th then kind of dropped it and now the ECM is in that range it is giving us possibilities so we might not be far from seeing something.

[Highland Snow]

it is a bit tedious waiting for something to come in cold wise but remember the GFS was showing blocking around the 5th then kind of dropped it and now the ECM is in that range it is giving us possibilities so we might not be far from seeing something.

BUS you are now the most trusted information source in The Kilted Thread in parallel with Lomond Snowstorm. How did you hone your Model interpretation skills?

[Buriedundersnow]

BUS you are now the most trusted information source in The Kilted Thread in parallel with Lomond Snowstorm. How did you hone your Model interpretation skills?

 

don't think I am anywhere near LS yet got a long way to go before I get even close to near him.

 

I didn't even start looking at charts till 2011 so don't really know how good I am just like to spend time looking over the runs and the charts and tell what I see or might like to see probably get things wrong as much as I do right.

[Buriedundersnow]

LS or LORENZO or someone who has been at this a bit longer can you tell me how much credence there is in this whole theory about GFS shoving charts back in its runs as I have noticed something I will do a little post on it soon just wondered if there was any truth in it or not.

[Ravelin]

Looks like some potentially interesting developments there in FI, but then again aren't there always interesting developments in FI? Wouldn't be many complainign if the PV came to pay us a visit in time for Xmas.

 

 

It's been a dry and cool weekend here. Yesterday was sunny at times and felt reasonably pleasant at around 6-7C, but as soon as the sun dropped below the horizon it seemed to turn instantly much colder. Probably just psycological though as there wasn't much of a frost this morning. Today the sun was mainly kept out of sight behind a shroud of high cloud. I went for a walk up Bennachie in the afternoon with the dog and down at the bottom it was calm and felt cool with the temp around 5C. Once you got up on top at around 450m you were exposed to a stiff N/NW breeze it felt baltic! Enjoyable walk nontheless.

[Buriedundersnow]

here we go and hopefully I explain myself right.

 

now if we go along with the theory that I've heard said quite a few times in the model thread last winter that the GFS can push charts back in its runs and how it picks up things and drops them for them to be picked up later then I have noticed something that might be of interest.

 

if we all remember the GFS was picking up on and showing blocking into Greenland around the 5th but didn't really run with it and now the ECM is coming into this range it is starting to try and sort something out as you can see below from the last 4 runs day 10 chart

 

 

now note on the last chart there is two lows over America which I have highlighted in the chart below

 

 

now if we believe in the theory and remember its just a theory that the GFS can push charts back in its runs then look what the 12z threw out and when looking at the ECM output which I have put in again beside could be a sneak peek of the evolution we might see moving forward from the ECM as it is similar with the two lows over there

 

 

again people its just a theory and at the end of the runs so is subject to change but it was just something I noticed which caught my eye and with hearing a few times that GFS can push charts back thought I would share.

 

EDIT: couple of the charts not working right for the last day 10 chart just use the one I painted the arrows in.

 

just to add a little and get some excitement going look what started us off in 2010 theres the two lows and its not exactly the same setup but theres hints at something

 

Edited November 24, 2013 by Buriedundersnow

[NorthernRab]

-4'C now  

[blitzen]

here we go and hopefully I explain myself right.

 

now if we go along with the theory that I've heard said quite a few times in the model thread last winter that the GFS can push charts back in its runs and how it picks up things and drops them for them to be picked up later then I have noticed something that might be of interest.

 

if we all remember the GFS was picking up on and showing blocking into Greenland around the 5th but didn't really run with it and now the ECM is coming into this range it is starting to try and sort something out as you can see below from the last 4 runs day 10 chart

 

ECH1-240.gifECH1-240.gifECH1-240.gifECH1-240.gif

 

now note on the last chart there is two lows over America which I have highlighted in the chart below

 

ECH1-240.gif

 

now if we believe in the theory and remember its just a theory that the GFS can push charts back in its runs then look what the 12z threw out and when looking at the ECM output which I have put in again beside could be a sneak peek of the evolution we might see moving forward from the ECM as it is similar with the two lows over there

 

ECH1-240.gifgfsnh-0-324.png

 

again people its just a theory and at the end of the runs so is subject to change but it was just something I noticed which caught my eye and with hearing a few times that GFS can push charts back thought I would share.

 

EDIT: couple of the charts not working right for the last day 10 chart just use the one I painted the arrows in.

 

just to add a little and get some excitement going look what started us off in 2010 theres the two lows and its not exactly the same setup but theres hints at something

 

archivesnh-2010-11-20-12-0.png

The GFS is famed for this BUS and usually does it most winters at some stage.  You may be correct with your observations of course, who can tell.   Have a read  of Tamara's post below. She isn't hopeful for anything sustained any time soon.

 

 

 

This is where the conundrum lies. A +AO/-EPO correlation can and does exist, and this November is a very good example of that as it is the pattern that has dominated most of the month. Generally speaking, as I understand it, a large differential between the two indices is not sustainable indefinitely - and a deeply +AO generally forces the EPO positive eventually and a trough replaces the ridge over the Aleutians. This is influenced by seasonal wavelengths and it can be the case that the separation is not sustained into the winter months as the seasonal wavelengths lengthen.

 

 

But this is where the state of the stratosphere comes in and the likely future behaviour and direction of travel of the vortex in determing its strength and where the strongest areas of vorticity energy lie.  The current -EPO is assisting with the wave breaking pattern and keeping the bulk of the vortex over Siberia at present, but the strength of the vortex is muting any significant disturbance from troposphere/lower stratosphere activity to increase amplifciation of the pattern and reduce the +AO values that are a measure of its strength. On the basis of the vortex keeping strengthening and any wave breaking failing to have any impact (it has already been shown to have had little effect), then there is a real risk that it could re-organise itself back towards Greenland and Canada. This would reduce further the chances of any colder incursions getting south and a predominantly even flatter tropical maritime pattern would ensue with the jet stream aligned SW-NE.

 

Hence the best opportunties lie further into the winter in line with the +QBO being expected to decay through the winter and give better blocking opportunities. The +QBO is indeed not the deathknell necessarily of winter - but then at this time of year when the vortex is traditionally coming towards its strongest peak, then polar westerly assistance from the QBO that enhances the natural direction of travel around the polar stratosphere and makes it spin even faster is its greatest ally - and means that any available 'stick' put into it from the troposphere increasingly has to made of something akin to iron.

 

So we best hope we don't run out of sticks too soon, whatever they are made of

Edited November 24, 2013 by Blitzen

[lorenzo]

I agree, GFS will pick an idea and then drop it and then go with it again. To be fair this variance is visible across the models now and again. Another one to watch out for in Winter model watching is the dream cold charts 'getting stuck in FI'. Another tease the models like to roll out in lower resolution.

 

This high is really enjoying it's UK visit, absolutely everything steered NNE.

 

Over to TScahernaker for a Doodle

 

Really is a holding pattern for the weather, could be worse weather I suppose !

Edited November 24, 2013 by lorenzo

[Buriedundersnow]

I don't see where she is seeing that from as look at both charts from 2010 below we started with a ridge over there as our blocking came in so it is possible and as our blocking takes hold the ridge disappears and this was in a west QBO year as well as 2010 was so the ridge doesn't matter and it is the same looking set up with the two lows over Canada.

 

 

we need to worry about seeing blocking over here first then see what the ridge on the other side does after that just because there is a ridge over there doesn't mean we cant be knocked in the freezer a long period

 

EDIT: should add I don't really understand the strat and what she might be talking about might have picked it up wrong

Edited November 24, 2013 by Buriedundersnow