Model Output Discussion; into 2015

[chris55]

Certainly some interesting Purbs on the GEFS. In deep fl granted, but it's roughly half of them.

 

 

 

 

 

No matter how useless we think GFS is out in La La land, from past experience, when we get a consistent trend from this model of a pattern change to colder conditions way out, the notion of FI becomes less fanciful. The ideas may be somewhat dropped then re invigorated but id have a certain level of expectation that by day 10+ the actual pattern will be reflective of what GFS is toying with at present. No guaranteed snowmageddon of course , but an easing of the zonal train with some Atlantic ridging and a more blocked pattern generally is certainly welcome. How this could deliver for our little patch will need to be watched closely.

Edited January 5, 2015 by chris55

[Frosty.]

High Pressure, I had almost forgotten what they look like but the Gfs 12z shows a nice settled spell in FI.

[Nick F]

As expected, GFS op drops any HLB and delivers a Euro high instead..

 

http://max.nwstatic.co.uk/gfsimages/gfs.20150105/12/372/h500slp.png

 

Think we can write anything off for January.

 

Bit too early to write off the potential for block near the UK, I guess you refer to the potential for MLB, just on one run in FI timeframes isn't it?

 

It amazes me how people still have knee jerk reactions over developments still in FI. The GFS will always have varied evolutions at that range, even though it still indicates a mid-lat high building near the UK.

 

More runs needed before we can write off the potential for the high building north just west of the UK then moving in across the UK as has been signaled by recent op and para runs of the GFS.

Edited January 5, 2015 by Nick F

[Iceaxecrampon]

Yes - 12Z a downgrade - this weekends ppn not as widespread.

 

Ian

Edited January 5, 2015 by Iceaxecrampon

[offerman]

The charts are not looking great for any prolonged decent cold.  

 

 

Hi,

 

Sorry for O.T but does anyone know of a good weather station that i can link to my wi fi then view with my iphone 6 plus?

[mulzy]

Anyone else concerned about the 30 day met office forecasts? pretty much no mention of cold.

 

With the exception of a few GFS FI runs, can you see any signs/signals for cold?

Edited January 5, 2015 by mulzy

[chrisbell-nottheweatherman]

Offtopic post i know - please bear with me.  If there's little signal for anything cold, what is this chap banging on about?

 

https://www.youtube.com/watch?v=GUbX4BLroF4

[Summer Sun]

2m temps are shown to be slightly above average for the UK and a fair chunk of Europe over the next 8 days

 

 

From left to right - 8 day Anomaly, normal 2m temps, expected 2m temps

 

Some of the lowest 2m temps look to be over Greece and Turkey

Edited January 5, 2015 by Summer Sun

[swfc]

For what its worth im still at a loss why a rise in pressure to the west of the uk in fi is getting so much attention?I appreciate its popping up on gfs-gfs p but wheres the underlying trend for this to materialise?The 500mb charts don't hint at it altho I guess anything is possible tbh.Im the eternal optimist but its a long shot given the weather coming off the eastern seaboard a big ask at that distance!!Heres hoping anyway

[Bullseye]

Well the NAO and AO are expected to drop to at least neutral round mid-month and with MJO possibly going to phase 6/7 then don't think anything can be ruled out for this month. Of course colder conditions being less likely but possibility is there.

Edited January 5, 2015 by Bullseye

[Wivenswold]

Sorry, I rarely post in here as I'm not an expert but I do like to read expert opinion on what the models are producing and it gets a bit frustrating scrolling down comment after comment and seeing "We can write-off January" and "no signals for cold".

 

We're not all just interested in snow you know. I'm actually interested in all aspects of what the models are showing. If only there was a thread for people like me.

[mountain shadow]

With the exception of a few GFS FI runs, can you see any signs/signals for cold?

Well the NAO and AO are expected to drop to at least neutral round mid-minth and with MJO possibly going phase 6/7 then don't think anything can be ruled out.

[Snowman.]

As expected, GFS op drops any HLB and delivers a Euro high instead..

 

http://max.nwstatic.co.uk/gfsimages/gfs.20150105/12/372/h500slp.png

 

Think we can write anything off for January.

 

 

But in all fairness this is what a lot of people where saying at the start of December. Look how that played out a decent snow event for in the midlands many of who haven't seen snow since 2013. And the current date is January the 5th and there is 26 days left of January so in fairness that comment was rather pre-mature in its own nature.

Edited January 5, 2015 by SN0WM4N

[carinthian]

Offtopic post i know - please bear with me.  If there's little signal for anything cold, what is this chap banging on about?

 

https://www.youtube.com/watch?v=GUbX4BLroF4

Not seen this before. A good presentation and account.

 C

[Eugene]

As expected, GFS op drops any HLB and delivers a Euro high instead..

 

http://max.nwstatic.co.uk/gfsimages/gfs.20150105/12/372/h500slp.png

 

Think we can write anything off for January.

 

 

Great for cold temperatures actually and a blocked setup.

[carinthian]

Just seen the 850mb uppers forecast on the models for this Saturday. French Alps will be in melt down. 16c uppers in the Gulf of Genoa ! A little lower in Swiss and Austrian Alps but this coming weekend will see the freezing levels racing up the mountains.

 C

[nick sussex]

For those interested in the PM shot at the weekend  the UKMO does look a bit more amplified, and is likely to keep the cold uppers for longer.

 

The UKMO keeps a lobe of higher heights near Svalbard which helps to direct the low se further west, the GFS's drop heights there.

 

It's only a small window relatively speaking, the bigger picture though regarding any blocking to the west is still very uncertain.

 

NCEP seem to be having an extended holiday as the MJO data hasn't updated and they do a weekly in depth overview which again hasn't come out yet!

[winterof79]

High Pressure, I had almost forgotten what they look like but the Gfs 12z shows a nice settled spell in FI.

A cold and frosty high with an e/se flow dependent on where it sits.I have no problem with the output.Block still on the cards.Still some residual snow here on the deck.Not that warm is it? Opportunity knocks if we end up with a block anywhere round the latitude shown.

Edit:Ditto Eugene

Edited January 5, 2015 by winterof79

[nick sussex]

You can see the differences in the UKMO and GFS at T120hrs:

 

UKMO

 

 

GFS

 

 

 

 

 

 

 

[IDO]

The GEFS at D12 still solid in the development of the heights in the Atlantic but just a flip to more MLB than HLB:

 

 

Expect lots of flip flopping especially with the time to T0 still a way away. Though a toppler like December is probably the likely call bearing in mind we are repeating a pattern.

[Mucka]

GFS 12z op and ensembles less than inspiring for coldies with downgrades all around compared to the 00z but much too early to determine if a trend or run to run variation.

 

00z/12z ensemble comparison.

 

[nick sussex]

The GEFS at D12 still solid in the development of the heights in the Atlantic but just a flip to more MLB than HLB:

 

Meteociel_-_Panel_GEFS 4.png

 

Expect lots of flip flopping especially with the time to T0 still a way away. Though a toppler like December is probably the likely call bearing in mind we are repeating a pattern.

NCEP commented in their update that the GEFS unusually might be more amplified than the ECM ensembles:

 

HEIGHTS BUILD AGAIN IN THE NORTHEAST PACIFIC AND WESTERN CANADA

DOWNSTREAM FROM A TROUGH IN THE EASTERN PACIFIC...WITH AMPLITUDE

DIFFERENCES AS THE GEFS MEMBERS BUILD THE RIDGE FURTHER NORTH THAN

THE ECMWF ENSEMBLE MEMBERS.  SINCE THIS AREA IS DOWNSTREAM FROM

PERSISTENT CYCLONIC FLOW TAPPING WARMER AIR FROM THE

SOUTH...HIGHER HEIGHTS ARE POSSIBLE...SO WE PREFERRED TO

INCORPORATE THE GEFS FCST INTO THE OVERALL BLEND TO OFFSET THE

SLIGHTLY LOWER ECMWF HEIGHTS.

 

Further on this caught my eye:

 

WITH

THE CYCLONIC FLOW OVER THE CENTRAL PACIFIC CONTINUING EARLY NEXT

WEEK...THE EAST PACIFIC RIDGE AMPLIFIES ALL OVER AGAIN.

 

Its somewhat confused because there was talk of the ridge breaking down and a zonal flow taking over the CONUS for the second half of January, maybe that's still the case but timing wise can we get some blocking before that happens and then a favourable topple towards Scandi.

 

Also is the cyclonic flow in the central Pacific a good sign re the MJO?

 

[Barry12]

If people are going to going to write of months based on FI charts then they shouldn't be allowed to views the models. 'Theres no SSW, winters over', 'the FI shows no cold so we can rule snow out!' it would be fine if new members posted this, but people who have been hear for years still do it.

[MR EXTREMES]

Bit too early to write off the potential for block near the UK, I guess you refer to the potential for MLB, just on one run in FI timeframes isn't it?

 

It amazes me how people still have knee jerk reactions over developments still in FI. The GFS will always have varied evolutions at that range, even though it still indicates a mid-lat high building near the UK.

 

More runs needed before we can write off the potential for the high building north just west of the UK then moving in across the UK as has been signaled by recent op and para runs of the GFS.

It has to be said a mlb is a bloody good deal considering and many many mlb has eventually lead to something wintry especially in late jan and feb.

I wrote jan of a longtime ago but in all fairness a mid latitude block can end up anywhere only take a slight weakness in vortex then the mlb ends up a Scandinavia block or even but rare Greenland block.

I do however see solar forcing really mixing up the atmosphere but at the same time there are still background drivers that are in favour for something cold I punt for at least a week in feb for something more substantial if not then a uk high pressure things settled but frosty.

It's all pretty knife edge and looking at the models in detail you can see why.

We await the ecm on its verdict but this model has been if anything more against coldies and has been performing well apart from nov with its garden path greeny heights.

I don't believe any blocking will be sustained this month around Greenland.

[Eugene]

GFS 12z op and ensembles less than inspiring for coldies with downgrades all around compared to the 00z but much too early to determine if a trend or run to run variation.

 

00z/12z ensemble comparison.

 

 

 

 

Hey those charts hardly show any downgrade at all, certainly not worth pointing out with still plenty of runs showing 850 hPa temps of -5C next week.