Model Output Discussion - 30th November onwards

[Summer Sun]

Quick question

What is it with this high pressure over the uk?

 

Its all down to where the Jet stream sits

 

As you can see here its to the west of the UK

 

 

This allows the high to build to our east and drift to the UK

 

 

This results in some milder air coming up from the south though not all will see this at first, the south west, west Wales and Ireland would see the highest temperatures

 

[garbagebags]

Well lets hope that if one does materialise it actually backs up far enough West to deliver for the whole UK and not just the usual suspects. I'm still looking forward to this so called non event this weekend, there's still an outside chance of some snow on Thursday evening and Friday morning for NW England, with a cold weekend to boot with sub zero temps at night and temp crawling just above during the day.

 

Agreed. There is still a lot to cement. I mean, it's not beyond the realms of possibility that it could upgrade every run from now and be an actual stonker of a Northerly, for many many days. Blanketing the country in snow. Alas, people seem to prefer talking about easterlies that aren't even being shown in the deepest realms of FI. 

[Mucka]

Well, surely IMBYism comes into play. Most people on this forum are English and most of those are southern centric, therefore Scotland would have to be buried in snow in order for Portsmouth to get a dusting from a northerly 9/10. Thus, those in the South-east will obviously prefer the easterly. Not only are you looking at a less reliable way of getting cold into the UK than a northerly with a Greenland block but you have now got a greater audience all intently waiting for the next frame. Resulting, - as you so aptly put- in casualties with a lot more than toys and prams being thrown in this forum  

 

 A Greenland block brings a lot more scope for country wide cold and snow than most Scandi highs. You can play around with the orientation, shape and placement of one more than a Scandi high and still pull in some very cold uppers (you can have one fail as well of course) as well HP generally being further away from the UK which helps with potential ppn.(Often with a Scandi high high pressure will be across the N of the UK) 

An Easterly can be better for the SE contingent but not necessarily and if there is any IMY'sm it is from the SE contingent generally with a Scandi high because a Easterly will rarely deliver further N and W unless you get the classic battleground set up. I am IMBY with an Atlantic ridge Northerly because I can get Cheshire gap showers but they are rarely any use for the South.

A Greenland block however will generally bring in a NE flow which can be just as good for the SE if not better as the NW depending on the exact set up so I think Nick was spot on with his post. We should always favour a Greenland high over a Scandi high IMO though accepted there is more potential from a Scandi in the SE than the North and West and the reason I chase them is because as well as bringing cold there is potential for retrogression - to Greenland!

Edited December 2, 2013 by Mucka

[Never snows where i live]

Its all down to where the Jet stream sits

 

As you can see here its to the west of the UK

 

 

This allows the high to build to our east and drift to the UK

 

 

This results in some milder air coming up from the south though not all will see this at first, the south west, west Wales and Ireland would see the highest temperatures

 

Thanks ss

[Gavin Hannah]

If one could order a winter, a Greenland High followed by a Scandi would be what I want. And for the High to move between each area, tilting on its axis (the uk) for the entire xmas-jan period.  

[shedhead]

Well the latast MO forecast is certainly not buying the ECM evolution, but it does hint at HP over the continent remaining close enough to keep the south and east largely dry...so something of a blend between the big two perhaps? Also of note though is the longer term, which whilst not exactly a winter wonderland (no **** Sherlock!) at least doesn't call for a return to the Bermudian Blowtorch.  Couple this with the lastest FI output from GFS and the suggestion that Dec will at least be drier than average gains some credance. 

 

UK Outlook for Saturday 7 Dec 2013 to Monday 16 Dec 2013:

A cold start on Saturday with a widespread frost and some fog patches that may be slow to clear. Otherwise, a mostly dry day with variable cloud and some sunny spells. However, thicker cloud will bring patchy rain, stronger winds and transient hill snow into northwestern parts later. By Sunday, but more especially into the early part of next week, cloudier and milder conditions are likely to filter slowly from the northwest with a marked thaw of lying snow across the hills. However, many southeastern areas may remain cold with some clear spells and overnight fog. Thereafter, a northwest/southeast divide becomes established, with the more unsettled but often milder weather tending to be in the northwest, and the best of the drier weather towards the south and east.

UK Outlook for Tuesday 17 Dec 2013 to Tuesday 31 Dec 2013:

Generally unsettled, particularly towards the north and northwest of the UK, with the best of any drier and brighter conditions further south and southeast. Temperatures look to be around normal.

Issued at: 0400 on Mon 2 Dec 2013

Edited December 2, 2013 by shedhead

[Kentspur]

A Greenland block brings a lot more scope for country wide cold and snow than most Scandi highs. You can play around with the orientation, shape and placement of one more than a Scandi high and still pull in some very cold uppers (you can have one fail as well of course) as well HP generally being further away from the UK which helps with potential ppn.(Often with a Scandi high high pressure will be across the N of the UK) An Easterly can be better for the SE contingent but not necessarily and if there is any IMY'sm it is from the SE contingent generally with a Scandi high because a Easterly will rarely deliver further N and W unless you get the classic battleground set up. I am IMBY with an Atlantic ridge Northerly because I can get Cheshire gap showers but they are rarely any use for the South.A Greenland block however will generally bring in a NE flow which can be just as good for the SE if not better as the NW depending on the exact set up so I think Nick was spot on with his post. We should always favour a Greenland high over a Scandi high IMO though accepted there is more potential from a Scandi in the SE than the North and West and the reason I chase them is because as well as bringing cold there is potential for retrogression - to Greenland!

Scandinavian high and a strong east to north east flow any day over a Greenland high- sure most the population will agree as most don't live up north west- though how about a Greenland high and then a scandi so we can all join in- I still feel A decent easterly will occur at some point this winter but they are far more prevalent in late winter it seems

[SW Saltire]

 A Greenland block brings a lot more scope for country wide cold and snow than most Scandi highs. You can play around with the orientation, shape and placement of one more than a Scandi high and still pull in some very cold uppers (you can have one fail as well of course) as well HP generally being further away from the UK (Often with a Scandi high high pressure will be across the N of the UK) which helps with potential ppn.

An Easterly can be better for the SE contingent but not necessarily and if there is any IMY'sm it is from the SE contingent generally with a Scandi high because a Easterly will rarely deliver further N and W unless you get the classic battleground set up. I am IMBY with an Atlantic ridge Northerly because I can get Cheshire gap showers but they are rarely any use for the South.

A Greenland block however will generally bring in a NE flow which can be just as good for the SE if not better as the NW depending on the exact set up so I think Nick was spot on with his post. We should always favour a Greenland high over a Scandi high IMO though accepted there is more potential from a Scandi in the SE than the North and West and the reason I chase them is because as well as bringing cold there is potential for retrogression - to Greenland!

Firstly, i wasn't disagreeing with what Nick had said. I was merely posting my reasoning behind why i personally am not that obsessed by an easterly from an IMBY pov (this may change if we get an easterly in february when i am located in Stirling, which is much closer to the east coast than Dumfries). It is simple really, i see far more snow from a greenland block and the battleground scenario can deliver in a very big way for a region affected by the solway firth. Therefore, if i lived in the south of England generally an easterly would give me more snow and therefore i would chase it to verification. 

I take your point that a North-easterly can be obtained from a Greenland block as well. I also wholeheartedly agree that a Greenland block is the best and in general most substantial, in this regard you are preaching to the converted

[SW Saltire]

Agreed. There is still a lot to cement. I mean, it's not beyond the realms of possibility that it could upgrade every run from now and be an actual stonker of a Northerly, for many many days. Blanketing the country in snow. Alas, people seem to prefer talking about easterlies that aren't even being shown in the deepest realms of FI. 

It is beyond the realms of possibility really... you are talking about an incredibly rare chance

[nick sussex]

Looks like a small upgrade already at T48hrs  on the GFS 12hrs run, the upstream pattern looks a bit more amplified.

[Mucka]

Scandinavian high and a strong east to north east flow any day over a Greenland high- sure most the population will agree as most don't live up north west- though how about a Greenland high and then a scandi so we can all join in- I still feel A decent easterly will occur at some point this winter but they are far more prevalent in late winter it seems

 

I think you will find a Greenland high delivers that synoptic of a strong NE flow much more often than a Scandi which is often a slack SE but like you say let's have both or and some HLB that moves bewteen Greenland, Iceland and Scandi a la 2010   (Just shows how difficult is to get snow in our BY's in England even once we are luck enough to draw in the cold)

 

[Joe Levy]

Considering the small adjustments westward on the 12z so far, whilst I would say that any major changes are unlikely, there is still certainly some room for improvement in the extent of the cold and possibly the precipitation as well, but much of this is coming down to last minute corrections

[lorenzo]

Quite a vigorous low on this run.

 

 

Edit - add wind gusts from GFS. Amber warnings from that I would think.

 

Edited December 2, 2013 by lorenzo

[Matty M]

925hPa winds look quite strong Thursday morning!

 

Could be some damaging wind gusts ahead of the CF.

 

Looks very nasty for parts of Northern UK

 

[Matty M]

Some pretty severe weather for parts of northern Europe incl. Denmark/ Germany

 

Blizzards for many.

 

[Matty M]

Not much differences in broad details out to T108hrs. Northerly now looking like a very fleeting affair.

Although that low will pack a serious punch for many northern parts.

[Gavin Hannah]

Aviemore will get a proper pasting, too bad the milder weather returns before the snow can be used for snowsports......

[TwisterGirl81]

Some pretty severe weather for parts of northern Europe incl. Denmark/ Germany

 

Blizzards for many.

 

 

Argh! If only

 

I always wander why the most severest storms always tend to avoid southern England?

[Mark Bayley]

While many are probably focused on how cold it will get, and snowy, its worth highlighting the potential for quite strong winds Thursday afternoon. This is especially the case for Scotland, Northern England/Wales/Ireland where gusts of 60mph quite widely seems possible (and higher in more exposed locations). Be interesting to see the UKMOs take

Edited December 2, 2013 by Mark Bayley

[Joe Levy]

Argh! If only

 

I always wander why the most severest storms always tend to avoid southern England?

Because southern England is a very small area of the globe, and a relatively sheltered region at that! I share your disappointment, however when severe snowy weather does hit us it is far more exciting, because it is so rare!

[Cecil Hogmanay Melchett]

The chart at 108 hrs is not a nice sight at all for coldies.

Look at the high latitude's and its really hard to see any blocking,at all!

Fair to say for those who dont see any snow this thur/fri its going to be quite a wait for another opportunity..

[shedhead]

Quite a vigorous low on this run.

 

gfs-0-66.pnggfs-5-66.pngRtavn6619.png

Sure is. However half the problem here is the speed in which it's moving, the cold air gets dragged away pretty much in line with the 06 GFS, with pressure building strongly again from the SW before the end of Friday.  Somewhere in the north is gonna get a proper pasting for sure though if this track and intensity verify.

Aviemore will get a proper pasting, too bad the milder weather returns before the snow can be used for snowsports......

'Proper pasting'....snap

[Matty M]

The chart at 108 hrs is not a nice sight at all for coldies.

Look at the high latitude's and its really hard to see any blocking,at all!

Fair to say for those who dont see any snow this thur/fri its going to be quite a wait for another opportunity..

I don't know. I have seen a lot worse charts than this. Obviously the PV piece camped near Greenland is not ideal but interesting high over Alaska heading poleward.

 

[picog]

The cold snap appears to be very "snap-like" — not looking good thereafter for coldies!

http://www.wetterzentrale.de/pics/MT8_Manchester_ens.png

[Barry12]

36 hour cold blast according to the GFS 12z