Model Output Discussion - The Start Of Winter

[Barry12]

Another good run on the 18z GFS, snow to lower levels could be a real possibility, even in the south next week.

 

 

A bitter Northerly wind!

[shaky]

...albeit the 12z clusters into that timeframe *could* prove to be.

could you elaborate further ian!! Anything interesting on the horizon from the mogreps end!!

[fergieweather]

could you elaborate further ian!! Anything interesting on the horizon from the mogreps end!!

Potential, albeit lower, for more potent northerly outbreak(s) or even discrete deep lows into N Sea can't be discounted. Much water to go under bridge into that period until we see better consensus.

[Chris K]

Another good run on the 18z GFS, snow to lower levels could be a real possibility, even in the south next week.

 

 

A bitter Northerly wind!

Indeed, but a shame it looks like that High would topple further on and alas lower resolution kicks in. Some people would probably see snow though, more so the further North you are.

 

Some noticeable differences quite a bit earlier than that time frame so it will change I think it has been a decent evening for coldies...we just need it to get into the reliable! The Azores/Atlantic high looks like it is repeatedly attempting to nudge North as time goes on, but so far LP wants to keep it under control... Interesting model watching at the moment

Edited December 5, 2014 by Chris K

[knocker]

Interesting take on the 18z GFS re. the storm next weekend. Might blow a hole in any lengthy cold blast. Heaven forbid

 

At T156 it suddenly brings the main low south with secondary low forming in the North Sea. By t240 the Azores ridge is buildind behing the depressions and edging a NW into the UK with just above average temps.

 

Charts courtesy weatherbell

Edited December 5, 2014 by knocker

[Jason M]

Another good run on the 18z GFS, snow to lower levels could be a real possibility, even in the south next week.

 

 

A bitter Northerly wind!

I wouldn't think Snow would be that widespread from that chart. Probably limited to high ground and Scotland. 850s are nothing special and they need be at worst in the region of -7c before we can think about lowland snow from a northerly because of the maritime influence and early season SSTs.

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=180&mode=1

The blues can make things look more dramatic than they really are. Pretty standard winter fare from that tbh.

I'm not saying it wouldn't be better come the day, as too far away to be worried about detail, but I'm just mindful of any novices reading the thread :-)

With northerlies its worth just noting how quickly (or not) the colder upper air digs south. In this case not very quickly!

[Geordiesnow]

I'm not too interested in the detail of what each run shows, its about the trend and the 18Z does have some reletively decent amplification so that is the good news. 

 

That low pressure system that crosses Hudson Bay towards Greenland could be a bit of a spoiler but again, that sort of detail is most certainly subject to change. 

 

Shame the 18Z seems to of toned down that deep low pressure system to an extent and has it further North but the weather will remain the same regardless though, just slightly less windy. 

[Nick L]

The ECM clusters do indeed show plenty of cold solutions continuing from week 2 and beyond, primarily from a northerly quarter. There are equally strong signals for a more westerly pattern however. But it never looks particularly mild, average to cold is how I'd vaguely summarise it.

[fergieweather]

The ECM clusters do indeed show plenty of cold solutions continuing from week 2 and beyond, primarily from a northerly quarter. There are equally strong signals for a more westerly pattern however. But it never looks particularly mild, average to cold is how I'd vaguely summarise it.

Concur wholly, Nick.

[Barry12]

I wouldn't think Snow would be that widespread from that chart. Probably limited to high ground and Scotland. 850s are nothing special and they need be at worst in the region of -7c before we can think about lowland snow from a northerly because of the maritime influence and early season SSTs.

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=180&mode=1

The blues can make things look more dramatic than they really are. Pretty standard winter fare from that tbh.

I'm not saying it wouldn't be better come the day, as too far away to be worried about detail, but I'm just mindful of any novices reading the thread :-)

With northerlies its worth just noting how quickly (or not) the colder upper air digs south. In this case not very quickly!

 

If we can get snow to low levels in a NW, then we can certainly do it in a Northerly.

 

I don't just look at the blues

[BLAST FROM THE PAST]

Interesting take on the 18z GFS re. the storm next weekend. Might blow a hole in any lengthy cold blast. Heaven forbid

 

At T156 it suddenly brings the main low south with secondary low forming in the North Sea. By t240 the Azores ridge is building behing the depressions and edging a NW into the UK with just above average temps.

 

Charts courtesy weatherbell

Heaven forbid Knocker the mild arrives     Got to admit.....nothing is certain yet...but potential good northerlies are in the offing...

 

BFTP

Edited December 5, 2014 by Polar Maritime
To remove off topic references.

[Jason M]

If we can get snow to low levels in a NW, then we can certainly do it in a Northerly.

 

I don't just look at the blues

Sorry, not suggesting you do only look at the blues (was more aimed at lurkers so sorry!). I agree with you re NW outbreaks, but its still maybe too early really. SSTs are against us this early on. As Fergie indicates, something more potent could occur than this run though.

[nick sussex]

The GFS 18hrs run with a slightly different take on things. I think a sticking point with this type of set up is shortwaves developing near Iceland which can slow down any cold advection south.

 

Upstream there are still uncertainties with several lows that might run east, do they run east and phase with the low over eastern Canada or do they head towards Greenland.

[Barry12]

Knocker you've been banging on about this mild weather for weeks now, I still don't see any sign of it on the models apart from in FI

[Mark Neal.]

Knocker you've been banging on about this mild weather for weeks now, I still don't see any sign of it on the models apart from in FI

I still struggle to see across much of the model output even into Fi, this so called above average temps which have been touted for weeks..

Anyway the 18z GFS is more amplified, small steps again.. Interesting to hear that the ECM clusters have some interesting northerly options, something brewing?! 

[Nick L]

Sadly I don't have access to the NH ECM clusters so I can't see the bigger picture.

 

Although a day or so out of date now, the ECM monthly clusters never really had a great deal of mild solutions either, with hints cropping up of lower heights over Europe towards the end of the month...interesting times!

[knocker]

Knocker you've been banging on about this mild weather for weeks now, I still don't see any sign of it on the models apart from in FI

 

I'm afraid I will have to differ as to the best of my knowledge the word mild hasn't featured in my posts. For example my posts tonight spoke of below average, some brief quite severe cold and average temps. I'm not fond of the rather silly term 'mild', always reminds me of when it was 1/3 a pint. Promise me you'll buck up Barry.

Edited December 5, 2014 by knocker

[Mark Neal.]

Sadly I don't have access to the NH ECM clusters so I can't see the bigger picture.

 

Although a day or so out of date now, the ECM monthly clusters never really had a great deal of mild solutions either, with hints cropping up of lower heights over Europe towards the end of the month...interesting times!

Excellent, it does feel like we are in a holding zone at the minute, its chilly and cold conditions likely to continue for next couple of days from time to time inbetween the fronts, with low pressure edging in from the NW, snowy for Scotland, rain for rest of UK to lower levels..  The lower heights is the big positive if that is to be the case, getting low heights into Europe is very good when trying to get deeper cold into the UK, as you say Interesting times,indeed!

Edited December 5, 2014 by Mark N

[damianslaw]

It remains a very changeable outlook, no two days the same, nothing benign about things. Subtle changes in the models today - all showing less of an intense low pressure system come Tuesday/Wednesday, but still showing a similar track i.e. to the north of Scotland pulling down a northwesterly airstream come Thursday. This is where reliable timeframe ends, some signs for a more pronounced mid atlantic high development, with low pressure heading down into central Europe, but uncertainty thereafter regarding development across NE USA/eastern USA seaboard and how energy interacts with the Jetstream..

 

There is a window for a colder drier shot to develop by end of next week, if we see an amplified flow off the eastern USA seaboard as this will help prop up heights over the atlantic which would most likely topple behind the low pressure but not before a blast of pure arctic air.. I can see a retrograde pattern developing again after this with further low pressure from the NW feeding into central Europe.

[Nouska]

Another good run on the 18z GFS, snow to lower levels could be a real possibility, even in the south next week.

 

 

A bitter Northerly wind!

 

Indeed. Although 850s are nothing special the wind chill will make on the ground temps feel very raw. After the weekend there are very few periods where 'feels like' temps are above freezing.

 

http://www.meteociel.fr/modeles/gfs/royaume-uni/windchill/3h.htm

[shaky]

Forget -5 850 temps but euro4 model shows 850 temps of -7 widely sunday evening and if that is not cold enough for snow even in a northwesterly flow then i dunno what type of northwesterly flow we need!! Lol

[ItNeverSnowsInWindsor]

Wow! Good to see the 18z GFS run follow up on the 12Z. It looks like there will be good chances of some substantial snowfall on the northern hills in the next 10 days or so at least. Wish I was back up in the Pennines!

[Nick L]

The usual rules apply in here no matter what time of day or night, no matter what your blood alcohol level is...thank you.

[Mucka]

UKMO sniffing those height rises to the NE I mentioned were on JMA so getting interesting in that respect. The remnants of the polar high is just waiting for some nice WAA so it can strengthen and it isn't hard to imagine a nice arctic high forming at a latitude that could influence our weather positively if it moved toward Greenland. Possibly not as bigger long shot as it seems, especially if ECM comes on board re the amplification downstream.

 

 

Of course of more immediate concern is the storm as it doesn't seem to be being downgraded much as D-day slowly approaches though time for small changes yet. Still it is hardly rare for us to be battered by such storms though it is a little rarer to have such fierce winds from the NW rather than W or SW. I enjoy a good storm and I'm looking forward to it, thought it goes without saying I hope everyone stays safe.

 

But before any of that we have this Sunday/Monday Northwesterly with a chance of wet snow falling to low levels in the North.

Here are some assembled charts in no particular order.

 

 

 

GFS ensembles not of much use as they are all over the place from T120 though it is hard to see from the graph alone without looking at the charts of each perturbation. Here they are though.

 

Edited December 6, 2014 by Mucka

[knocker]

Regarding the potential storm next week the GFS is still running the low north of Scotland and then SE into Denmark before a transitory ridge at T192 that gives some quite low temps, about -3C to -5C below average, for the much of the UK. Fortunately the winds seem to be abating a tad. Of course much can change before then and a careful eye has to kept on this low.

 

Charts courtesy weatherbell

Edited December 6, 2014 by knocker