Model Output Discussion - Stormy Period Inbound...

[bluearmy]

Given the snow drought, I would have thought 2 to 6 cms not really expected will be a real bonus for the lucky ones.

Ian - any more thoughts on. Friday's shortwave feature ? Too early to speculate?

Ecm extended eps remain consistent with the euro.trough

Signs of quite a variation of avenues at the end of the run. Some boring, some very interesting for coldies.

[Timmytour]

Just to reiterate for those following E4 snow accumulation prognoses: divide the raw amounts by factor of 2. I mentioned this yesterday.. it's to do with how model 'over-clumps' showers (problem thus in convective regimes but not re dynamic snowfall). I've seen some folk on Twitter taking 10-20cm raw signal literally. We go for 2-6cm generally, as per UKMO warning text.

Cheers IF.....   I note our friend in the Express is claiming that "The Met Office this morning has issued heavy snow warnings for much of the south"

You'll never get through to some people :-)

I must admit I for one have been very impressed with the little hints you have provided about the longer term outlook all through this winter. Sounds like some very impressive models are available to you guys (not to mention the individual skills in the interpretations of what they show)

Should things change in the next 10 days it will also augment the already considerable amount of respect I have for JH.  Sometimes reading his thoughts isn't the most exciting of things.....but that's principally because he's telling me what going to happen, not what I want to happen!   But through a large part of this winter I've noticed that he hasn't been on board, except perhaps recently, with many of the apparent changes that were coming.  From hereon in, without his support, I shall be even less inclined to jump on the "here comes the cold" bandwagons

[shaky]

Just to reiterate for those following E4 snow accumulation prognoses: divide the raw amounts by factor of 2. I mentioned this yesterday.. it's to do with how model 'over-clumps' showers (problem thus in convective regimes but not re dynamic snowfall). I've seen some folk on Twitter taking 10-20cm raw signal literally. We go for 2-6cm generally, as per UKMO warning text.

compared to yesterday's output the stream of snow looks like being pushed further north into the midlands now!! Do you think that will be the case or it will stay along the m4 corridor? Also the ukmo shows a channel low again this morning backing up the 12z output from yesterday! ! Surely it might be a possibility that the ukmo is right!! All eyes down for the 12z run!

[knocker]

Not a bad pattern to generate more European cold if verified 11-15d period, GEFS WSI Cluster Set 1 pic.twitter.com/KfJvjDekZQ

[bluearmy]

Not a bad pattern to generate more European cold if verified 11-15d period, GEFS WSI Cluster Set 1 pic.twitter.com/KfJvjDekZQ

 

glad i'm not the only one then knocks !  gefs finally catching up with the ecm extended

[johnholmes]

There is some indication on EC-GFS of polar heights rising/ridging in Spitzbergen west towards Greenland but nothing yet to suggest it is going to have any effect on the flow from 65N south and NOAA last evening showed nothing of this.

So I suspect little over the next 10 days to turn UK weather into deep cold from the NW-N, a continuation of what we have now. On the cold side for most, most of the time, with lows of varying depths and associated windiness. Also some prospect of fairly general snow over high ground even well south, chiefly as showers but with a possibility of more frontal type, be that pre frontal or back edge, who knows at anything beyond 3-4 days ahead. Some lowish areas out of Scotland may see some at times. None of this can be given deep conviction until the synoptic models, the main 3, give decent agreement on this sort of thing maybe at 72h and then closer.

I cannot see any major deep and long lasting cold outbreak happening for at least 2+ weeks. No I am not suggesting winter is over just being honest that I do not pretend to be able to do sensible predictions beyond 15 at most 20 days ahead.

[Ali1977]

There have been a few guys mention channel lows on the weekend, the UKMO model shows one on Sunday....I know lots is happening this week however does this look like it could verify - giving potential larger more widespread snow???

[carinthian]

 We are getting advance information on our snow portal service of some significant snowfall in the Alps on Saturday with the Polar Front aligning across a broad front and strong winds in action zone between between he Tm and Pm air mass.

The wider scope of the snow charts show some snowfall across Southern England and into N .France, possible at fairly low levels with a strong wind zone affecting parts of France and moving into Central Europe. This would indicate some sort of disturbance in the Polar flow ( Fri )  This same disturbance moving into Alps on (Sat) to produce a heavy fall.

 

 c

[Don]

There have been a few guys mention channel lows on the weekend, the UKMO model shows one on Sunday....I know lots is happening this week however does this look like it could verify - giving potential larger more widespread snow???

 

According to todays 6-15 day update from the Met Office, rain is more likely than snow in southern areas at the weekend.

[nick sussex]

According to todays 6-15 day update from the Met Office, rain is more likely than snow in southern areas at the weekend.

If that Channel Low actually turns up which at this point is a low probability its too early to say what could fall. Much depends on if this can engage some colder air from the north. A shallow feature would also be preferable,theres still a large degree of uncertainty upstream with low pressure exiting the eastern USA and how this might interact with troughing in the ne USA and Canada.

[IDO]

The GFS op has a channel low T84-90:  

 

Uppers look borderline if it verified.

[johnholmes]

 We are getting advance information on our snow portal service of some significant snowfall in the Alps on Saturday with the Polar Front aligning across a broad front and strong winds in action zone between between he Tm and Pm air mass.

The wider scope of the snow charts show some snowfall across Southern England and into N .France, possible at fairly low levels with a strong wind zone affecting parts of France and moving into Central Europe. This would indicate some sort of disturbance in the Polar flow ( Fri )  This same disturbance moving into Alps on (Sat) to produce a heavy fall.

 

 c

 

wanted as the snow is it may well scupper the Lauberhorn downhill!

[IDO]

Strongest winds overnight (P): 

 

 

 

[gottolovethisweather]

No I am not suggesting winter is over just being honest that I do not pretend to be able to do sensible predictions beyond 15 at most 20 days ahead.

 

Thanks as ever John for your insight and indeed you're certainly not suggesting Winter is over, as for a fair few of the population, it is simply just about to start! 

 

As the remainder of JH's original post suggested and Nick Fs from earlier for instance, regarding the snow it will most likely be transient stuff with rain, gales and thunder about too further into the outlook. Nonetheless this chappie is happy with things as they stand for all things wintry related.

 

Yes, there is a cold wintry bias focussed heavily towards Southern England in this post, for which I apologise profusely and it won't happen again.   

 

 

I won't be looking ahead any further than Wednesday as it is one messy setup but I'll trust other member's opinions on that for now.

 

Have a good day all.

Edited January 12, 2015 by gottolovethisweather

[SMU]

GFS looking good at 150

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015011212/gfsnh-0-156.png?12

 

more heights to the NE

 

also the P

http://modeles.meteociel.fr/modeles/gfsp/runs/2015011212/gfsnh-0-132.png?12

 

Strong positives so far-

 

S

[nick sussex]

OMG how exciting! at last, the GFS P looks good and the GFS also. I feel a Christmas song coming on!

 

Both early trends are so much better for cold potential.

 

The weather outside is frightful but the fire is so delightful and since we've no place to go, let it snow, let it snow, let it snow!

 

I can hardly contain myself! the GFS P delivers a northerly and the GFS a snow event in the higher resolutions.

Edited January 12, 2015 by nick sussex

[Mark Bayley]

Steve will probably like this run! Better heights to the N/NE and increased cold potential

 

 

We can only dream >

Edited January 12, 2015 by Mark Bayley

[Captain Shortwave]

A complete reversal on this morning

Day 6 charts

GFS op

Parallel

UKMO

GFS develops a Scandi high, the parallel looks slower but going the same way with the ridge toppling towards Scandinavia. The UKMO looks the worst of the three for cold and snow chances.

Edited January 12, 2015 by Captain shortwave

[terrier]

Sorry can't post charts as at work. But those winds on the gfs p look horrendous. Please hope those downgrade. Gfs looking better for cold at t150 but think any snowfall will be a transient affair away from the highest hill. With gales and heavy rain turning any falls into a slush feast.

[shaky]

Amazing output this evening so far!what a change!! Looks like my prediction of a slider low giving a significant snowfall across england could come true!!

[Ali1977]

The METO are not going with any long lasting deep cold, however this is still much better for coldies than last year....

[gottolovethisweather]

Sorry can't post charts as at work. But those winds on the gfs p look horrendous. Please hope those downgrade. Gfs looking better for cold at t150 but think any snowfall will be a transient affair away from the highest hill. With gales and heavy rain turning any falls into a slush feast.

 

Active weather pattern for sure, assuming no loss of life occurs we residents of the UK should stay safe and any transient snow will be welcomed by a great many in here, I would imagine. 

Edited January 12, 2015 by gottolovethisweather

[nick sussex]

A complete reversal on this morning

Day 6 charts

GFS op

Parallel

UKMO

GFS develops a Scandi high, the parallel does not though but extends the northerly with a decent Atlantic ridge. The UKMO looks the worst of the three for cold and snow chances.

Its just so typical, the UKMO has to harpoon the feel good factor! Looks like my Christmas albums going back into storage!

[Beverley Lass]

 

The storm seems to have taken the UK away completely

in this view !?

 

B. 

[Severe Siberian icy blast]

OMG how exciting! at last, the GFS P looks good and the GFS also. I feel a Christmas song coming on!

 

Both early trends are so much better for cold potential.

 

The weather outside is frightful but the fire is so delightful and since we've no place to go, let it snow, let it snow, let it snow!

 

I can hardly contain myself! the GFS P delivers a northerly and the GFS a snow event in the higher resolutions.

Haha glad to hear a more positive Nick today mate !

Yes looking much better moving forward , a cold wk by any standards , and an interesting wkend aswel , much better model viewing for sure . Still finely balanced though and we need to see these charts echoed in the meto really , there models have been bang on the money so far , but yes positives going forward .

Just out of interest Nick , where do you live? Because if you live in France then iv never saw someone show so much interest in a country they don't actually live in lol !