Model Output Discussion 12hrs. 01/10/13

[Polar Maritime]

ECMWF continues the theme from yesterday mornings run.. look were the Vortex wants to sit with all that warm air over Greenland, and how far South the Jet is, we could get a stunning Northerly flow from this set-up.

 

Edited October 14, 2013 by Polar Maritime

[Frosty.]

The Gfs 00z op run shows an unsettled outlook with low pressure generally just to the west of the uk and with high pressure across the continent, later this week looks like becoming very mild / rather warm across southern britain but on the flip side, the far north of the BI looks like becoming rather chilly for a time but by the end of the week, very mild s'ly winds are also pumping north across scotland too, so a much milder spell ahead, especially the further south/se you are, the mildness enhanced by the best of the dry and sunny weather towards the southeast with occasional higher pressure whereas the north & west of the uk look like bearing the brunt of the atlantic weather but all areas look windy at times with spells of rain interspersed with brighter, showery and fresher interludes but it's mainly tropical maritime air swamping the uk on this run with only very brief incursions of oceanic air, this mainly across nw britain.

[Captain Shortwave]

ECMWF continues the theme from yesterday mornings run.. look were the Vortex wants to sit with all that warm air over Greenland, and how far South the Jet is, we could get a stunning Northerly flow from this set-up.

 

It needs yet again to repeat this on it's next run, though frankly I'm not holding much hope as it didn't the last 2 promising runs we saw. At least we can pretty much guarantee that the GFS is wrong, but I still feel we are stuck in a persistent pattern so unless the jet stream is going to have a sudden west to east surge which can finally flatten the Euro ridge then we are still pretty much stuck.

For the time being the outlook remains average to mild, and more importantly very wet.

Edited October 14, 2013 by Captain shortwave

[phil nw.]

UKMO T72hrs.

 

 

that's an impressive cold pool building to our east and north for mid-October-right down to 50deg N over Russia.

No sign of that being swept away at the moment. with the jet on such a southerly track.

[Frosty.]

In my heart, I would love the ecm to be right but the realist in me tells me the gfs 00z is likely to be closer to the mark...i.e..becoming mild or very mild, unsettled and windy at times for the next few weeks.

Edited October 14, 2013 by Frosty.

[Yarmy]

ECMWF continues the theme from yesterday mornings run.. look were the Vortex wants to sit with all that warm air over Greenland, and how far South the Jet is, we could get a stunning Northerly flow from this set-up.

 

 

 

Notable surface pressure over Siberia too. Big Siberian High building? 

 

Meanwhile back in Blighty, it looks...wet. At the start of the October, it looked like we might be under an immovable Euro High all month.

[nick sussex]

It's always a bit more interesting when you have model disagreements. Initially the main difference is how far south the jet is, the GFS has this furthest north, the UKMO is midway between that and the ECM.

Later the GFS wants to drop heights over Greenland where as the ECM keeps these higher and keeps a deep PV to the ne.

This difference is more important going forward for how the pattern could develop after this point.

In terms of any cold its not really the movement of the PV thats an issue but where it decides to set up shop, if you keep this to the east theres always a chance of some cold heading south on its western flank, the GFS moves this to Greenland in its FI before transferring this much further west, this still gives a chance of some cold from the east. We all know what happens if it sets up to the north!

If you look at last nights ECM ensemble mean this has the jet further south than the GFS and so you could say that there is certainly a decent cluster of solutions supporting this mornings ECM 00hrs run.

Given the models difficulty in trough disruption the ECM could well look much colder in the coming days if its correct in its original idea this morning. If not and we see a more blended mid point between it and the GFS then generally it looks a stalemate with troughing stuck over the UK.

In that case then a chance of something colder in the far north but overall then generally mild.

The latest ECM ensembles will be out soon, lets see what they come up with.

[Summer Sun]

Latest from, Gibby relatively mild but more importantly wet and windy little or no chance of any quiet and cold weather developing anytime soon

 

All models still show Low pressure over Southern England today. Through tonight the rain and showers circulating this feature thins out as the low fills and moves East, Tomorrow will see a dry day for many as a slender ridge of High pressure crosses the UK. On Wednesday a front moves NE in association with Low pressure over the Atlantic slows down as it reaches Scotland. The rest of the week then looks changeable with some drier and brighter spells in the South where it will become mild while Northern areas staying cloudier and often wet as well as colder than elsewhere.

 

GFS through the weekend and throughout next week shows mild air extending to all areas with rain and strong winds on frequent occasions for all as Low pressure up to the NW repeatedly sends troughs NE across the UK in temperatures well up to and at times above the seasonal normal. Little changes in the latter stages of the run with the only minor change being slightly colder conditions developing slowly again over the North as winds turn Easterly.

 

UKMO has cyclonic winds blowing over the UK to end next weekend, SW'ly in the South and SE'ly in the North. The weather would remain unsettled and basically mild with rain or showers carried North through Britain with some regularity and with shorter drier and brighter spells too, these mostly towards the East.

 

GEM shows less mild conditions than the other models with an Easterly flow across all Northern areas for much of it's run. The South would be reasonably mild but all areas would be subject to Low pressure areas down towards the West and SW carrying repeated bands of rain and strong winds across most areas, heaviest in the South and West.

 

NAVGEM too shows an unsettled and sometimes windy outlook with Low pressure coming ever closer in towards the UK next weekend with cooler SE winds in the North, milder SW winds in the South with rain at times for all.

 

ECM shows unsettled conditions next weekend when the North stays rather chillier with a fresh to strong and chilly ESE wind while the South sees more SSW winds carrying bands of rain at times mixed with some more showery interludes with a little brightness. The end of the run if anything strengthens the unsettled theme with gales and heavy rain likely to be sweeping in from the SW by the middle of next week. 

 

The GFS Ensembles show a typically wet and windy set this morning with an almost total Atlantic influence so no cold weather expected for the next few weeks. There will be a lot of rain at times for all areas with the North feeling a chilly breeze from the ESE.

 

The Jet Stream shows the flow to the North weakening over the coming days as a new arm sets up much further South across the Atlantic towards Southern Britain and France from the end of the week and next.

 

In Summary the weather will become more generally unsettled later this week and then remain in situ thereafter. For the North a chilly ESE breeze off the North Sea will keep things a little chilly for a time but the vast majority of the time the weather will be relatively mild but more importantly wet and windy with most places seeing much more rain than they have seen for some considerable time. I can see little or no chance of any quiet and cold weather developing anytime soon from this morning's output so fog and frost problems over the coming two weeks should be minimalistic.

 

http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm

[BLAST FROM THE PAST]

 

Notable surface pressure over Siberia too. Big Siberian High building? 

 

Meanwhile back in Blighty, it looks...wet. At the start of the October, it looked like we might be under an immovable Euro High all month.

 

 

 

Yes it did seem that way and we didn't get as glorious a spell we could have had due to too much cloud cover.

Now the change is within view, approximately halfway through the month with a wetter, much windier picture developing with gales or even storm force winds in places.  I alluded to this in my autumn thoughts but suggested the initial attack would come from NW/WNW with jetstream moving south as month went on.  It seems the initial attack is coming from W/WSW [further south than anticipated].

I have some notes expecting a potential stormy period, particularly initially for NW Scotland then moving south over the whole of the UK as the jet shifted south. Maybe the intial storminess will be from secondary Lps / troughs swinging up front edge of the main trough.

Anyway the idea is there and I think we'd better be prepared for a deep LP to impact areas of the UK not normally exposed to gale or severe gales.

I'm not anticipating any real cold outbreak at all this month which even as a coldie is of no concern as I think the current weather pattern developing and the hemsipheric set up is quite interesting to say the least.

Re ECM or GFS......well earlier in month the ECM got a notch as it picked up the retrogressing HP first....so one nil there......I have a set up whereby we have a block from Norway to Iceland back end of month with LP attack frm way SW.....I suppose ECM currently for me if it went on. 

BFTV made a nice call way back in Aug I think re 'overview' of Oct.

 

BFTP

Edited October 14, 2013 by BLAST FROM THE PAST

[TootyFruity]

Hi sorry for my ignorance I'm just getting used to the models could someone tell me where the vortex is best placed to aid a cold winter for the uk ? Is it Greenland ?

[MR EXTREMES]

Just to clear things up before these personal digs get out of hand (which may I remind you are not tolerated by the mods in this thread)

 

I do post cold charts however there is very little in the way of cold in today's outputs so its near impossible to post anything else.

 

If you don't like my or anyone Else's posts for that matter all you have to do Is click your name and select manage ignore prefs

Im sorry summer sun you are only talking about the models and what they show and I was being a little childish throwing toys out of my pram but ive put them back now.

over all the models are throwing up some absolutely stunning charts with milder air over most of the uk and perhaps a chance of some cold over northern Scotland very possible 20c in the south and in northern Scotland possible single figures and frost so all in all im getting rather excited.

[nick sussex]

Hi sorry for my ignorance I'm just getting used to the models could someone tell me where the vortex is best placed to aid a cold winter for the uk ? Is it Greenland ?

You either want it to the east/ne or stuck to the west of Greenland. You sometimes get splits in the PV in this case one to the west of Greenland and one to the east, which leaves nice room for a Greenland high. Definitely not over Greenland as that turns into a horror show for cold and snow lovers.

[TootyFruity]

You either want it to the east/ne or stuck to the west of Greenland. You sometimes get splits in the PV in this case one to the west of Greenland and one to the east, which leaves nice room for a Greenland high. Definitely not over Greenland as that turns into a horror show for cold and snow lovers.

[Summer Sun]

At the moment Saturday looks the best chance of getting 20c in the south

 

 

Sunday is possible but it would be isolated to a smaller area

 

[Summer Sun]

You either want it to the east/ne or stuck to the west of Greenland. You sometimes get splits in the PV in this case one to the west of Greenland and one to the east, which leaves nice room for a Greenland high. Definitely not over Greenland as that turns into a horror show for cold and snow lovers.

 

I was wondering that same as TF where on the chart randomly picked does it show the vortex? is it the blob of purple?

 

Edited October 14, 2013 by Summer Sun

[TootyFruity]

Thanks Nick last year the polar vortex got blasted into pieces which I think I'm right in saying helped our winter turn cold are thee any signs of this happening again this year or is it too early to tell ? I understand model and weather forecasting is not very good way out in FI but as with everything there must be a certain pattern that may be showing as to what the winter may hold !

And the massive cold pool just north of the uk why are people getting excited about it will the Azores high fall away back to Spain etc allowing that cold pool to fall over us is this why people are getting a little giddy ?

[BLAST FROM THE PAST]

I was wondering that same as TF where on the chart randomly picked does it show the vortex? is it the blob of purple?

 

I think you are being mischievous SS

 

 

BFTP

[TootyFruity]

I was wondering that same as TF where on the chart randomly picked does it show the vortex? is it the blob of purple?

[That ECM]

You either want it to the east/ne or stuck to the west of Greenland. You sometimes get splits in the PV in this case one to the west of Greenland and one to the east, which leaves nice room for a Greenland high. Definitely not over Greenland as that turns into a horror show for cold and snow lovers.

Or hammered by SSW!

[TootyFruity]

Hi SS I do believe the purple blob is the vortex !!!

Probably get slatted now (holding my breath)

[BLAST FROM THE PAST]

Hi SS I do believe the purple blob is the vortex !!!Probably get slatted now (holding my breath)

You are correct

 

BFTP

[Summer Sun]

I think you are being mischievous SS

 

 

BFTP

 

lol I honestly didn't know

 

Thanks for the above reply

[Polar Maritime]

If we could follow on from where this mornings ECMWF run leaves us, it would look something like the CFS..

 

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=174&mode=0&carte=0&run=0

[phil nw.]

Thanks Nick last year the polar vortex got blasted into pieces which I think I'm right in saying helped our winter turn cold are thee any signs of this happening again this year or is it too early to tell ? I understand model and weather forecasting is not very good way out in FI but as with everything there must be a certain pattern that may be showing as to what the winter may hold !And the massive cold pool just north of the uk why are people getting excited about it will the Azores high fall away back to Spain etc allowing that cold pool to fall over us is this why people are getting a little giddy ?

Hi TF,

If we get a high around Greenland with plenty of cold air over to our NE then this brings the winds in from that direction which draws all that cold towards the UK.The one caveat is that the jet is far enough south so any lows are shunted on a lower latitude than the UK so we remain on the cold side of the PFJ.

Here is a classic example from Nov.2010.

 

the start of that famous severe cold spell that carried on through Dec.2010.

Of course we are too early for this yet and only speculating on things but those are the sort of setups to look for.

As Nick S. said we don,t want the main core of the vortex(deep blue/purples)over Greenland if looking for cold or else we inevitably get stuck under warming south westerlies.

[lorenzo]

Vortex off on it's travels, map of the core low heights at 30hpa

https://mapsengine.google.com/map/edit?mid=zxmSRTLk6qjA.kxuYmNkEhXn0