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Model Output Discussions 18z 31/01/2016

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Late night GFS gives a very good snow event.

Significant snowfall for the northern half of the country ie. Cumbria northwards remaining as snow throughout on northern flank of the low, always the potential for such with the United Kingdom being targeted at by Atlantic by southerly tracking systems with cold air not terribly cold in situ.

image.thumb.png.b3b3ab1901b615862fc39c19image.thumb.png.ea46c1072ebf49e61b64ab5a

As low trundles across the country colder air undercuts turning the remaining rain to snow. 

Rain to snow event possible for southern districts, I would not dismiss anything from happening next week! 

Topsy-turvy....exciting :santa-emoji:

image.thumb.png.4583e6c3b5e484ec95bc29cbimage.thumb.png.0210a276d352ce623f09fb0a

Edited by Daniel*

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The GFS continues this morning to show an unsettled cool W/NW flow into next week.

a.pngb.pngc.png

With the weekend (Sat) showing some heavy rain crossing the UK, With gales in the S/W and some big temperature differences North to South shown by the in-house NetWx-SR Model.

a.pngb.pngc.png

Edited by Polar Maritime

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10 hours ago, BLAST FROM THE PAST said:

Well a quick one for me but something to think about and something to like about what we see.  Models this time haven't shown the promised land and then battled against each other as to will it hold, has it flipped to total mild mush and then do we get a half way house.  What we are seeing is a gradual subtle upgrading day by day.  This is getting very interesting and its NOT await 2nd half of Feb either,

Edit -  had looked at JMA, ECM, UKMOt - just looked at 12z GFS.....ok here we go

 

BFTP

I don't see any upgrades BFTP,only wind and cold rain from all outputs.Judging by the likes for the post others must be seeing it too though.

Edited by winterof79

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On the ECM 0z you've got North Westerlies, Northerlies and lee Easterlies but ironically its a powerhouse Westerly that's about to bring the coldest uppers in at 240!

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Not sure any of the models are cold enough for low land snow next week.

Was hoping for better after yesterdays ECM.

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8 minutes ago, feb1991blizzard said:

On the ECM 0z you've got North Westerlies, Northerlies and lee Easterlies but ironically its a powerhouse Westerly that's about to bring the coldest uppers in at 240!

At 240z where have I heard that before this season:closedeyes:

One major lesson learned this winter.The models are becoming even less accurate beyond 120z.

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To be honest I see little but cold rain and wind......maybe some wet snow in the north to low ground. 

Some individuals continue to bang the drum for narnia but one gets the sense they are only trying their hardest to make a mediocre output tie up with their previous predictions. 

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3 minutes ago, winterof79 said:

At 240z where have I heard that before this season:closedeyes:

One major lesson learned this winter.The models are becoming even less accurate beyond 120z.

I disagree. They only seem less accurate because of greater hope being placed in the medium range due to nothing showing in the reliable. 

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Just now, winterof79 said:

At 240z where have I heard that before this season:closedeyes:

One major lesson learned this winter.The models are becoming even less accurate beyond 120z.

I don't think they are less accurate tbh, weve always had fantasy synoptics, 2012 we had some ridiculous Easterlies shown within a reasonable timeframe, its just that because that year at least we had some sort of a cold snap, peoples perceptions towards the models were more tolerant.

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4 minutes ago, Radiating Dendrite said:

I disagree. They only seem less accurate because of greater hope being placed in the medium range due to nothing showing in the reliable. 

They haven't Sunday nights storm sorted yet and it's less than 3 days away! All models have chopped and changed on this system alone.

There are plenty other examples throughout the winter imo

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Either way, more tragically bad output this morning, with nothing but more wind and cold rain on offer. Nothing much more to add really, disappointing all round.

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Another day another set of underwhelming output. Gfs ecm show some polar maritime shots. But these away from highest hills will deliver at best some slush. Looks like for many of us cold rain with gales. I would settle now for some high pressure sypnotics just to dry areas out. 

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15 minutes ago, terrier said:

Another day another set of underwhelming output. Gfs ecm show some polar maritime shots. But these away from highest hills will deliver at best some slush. Looks like for many of us cold rain with gales. I would settle now for some high pressure sypnotics just to dry areas out. 

There is more chance of colder shots than settled anticyclonic I feel tbh when evaluating the 00zs

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8 hours ago, joggs said:

All respect bftp,you said something along the lines a wk or two back.Even maybe more coldest.

Indeed Set up looks good but we just cannot engage in the coldest air,  Every attempt this winter has been scuppered but we are in our 'best shot' period imo because I have a feeling there'll be some 'real mild' about late in the month.  We have LPs shifting on southerly track but a wedge of trough hangs around to our NW preventing real cold air flooding south.  Following is classic example.

ecmt850.072.png

 

ecmt850.096.png

So when we get a lovely tracking LP like this.....real cold air not in place

 

ecmt850.144.png

 

BFTP

 

Edited by BLAST FROM THE PAST

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5 minutes ago, BLAST FROM THE PAST said:

Indeed Set up looks good but we just cannot engage in the coldest air,  Every attempt this winter has been scuppered.  We have LPs shifting on southerly track but a wedge of trough hangs around to our N/NW preventing real cold air flooding south.  Following is classic example.

 

 

But it doesn't really BTFP, there is absolutely no decent blocking highs at northern latitudes anywhere near close enough, (as has been the case since Oct/Nov). There is, and has been for months an uber vortex sat over Greenland dictating play, and pretty much nothing else.

The only difference in the next week or two is the south will probably get some of what the north west in particular has endured since November as the jetstream sinks a little south.

 

 

 

Edited by northwestsnow

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13 minutes ago, northwestsnow said:

But it doesn't really BTFP, there is absolutely no decent blocking highs at northern latitudes anywhere near close enough, (as has been the case since Oct/Nov). There is, and has been for months an uber vortex sat over Greenland dictating play, and pretty much nothing else.

The only difference in the next week or two is the south will probably get some of what the north west in particular has endured since November as the jetstream sinks a little south.

 

 

 

If you are chasing the holy grail blocks you were always likely to be disappointed.  Southerly tracking LPs and them tracking NWN to ESE usually is likely to provide wintry chances generally but we are getting scuppered by an extension of the trough preventing a good northerly flood of arctic air, suppose it depends what you are after....and one must forget massive scandi or GHP blocks

 

BFTP 

 

Edited by BLAST FROM THE PAST

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GFS ensembles aren't really showing anything different for my part of the World. The only comfort is that the high temperatures predicted have been downgraded by quite a lot as they get within 5 days. At this stage either a return of winter (didn't do too bad this winter) or a Spring start would be appreciated.

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3 minutes ago, Jonathan Evans said:

I know the mods ain't going to like this but.....Roll on Spring - can't come soon enough now 

To be honest, and im sure the mods will agree, despite an overwhelming majority wanting to see winter weather in winter, the thread has been clean,tidy and respectful in the face of the most shocking model output since early November,its already the wettest winter on record in the north west and thats before next weeks deluges.Hopefully we can get a nice warm summer to dry out the sodden ground and  start again next November with optimism.

The 00z runs are the final nail for me, that PV just isnt going to give up tormenting us until Febs out imo.

Just a quickie regarding the models, i actually think GFS has been pretty good over the last few months and i will certainly pay more attention to it in the future. :)

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1 hour ago, January Snowstorm said:

They haven't Sunday nights storm sorted yet and it's less than 3 days away! All models have chopped and changed on this system alone.

There are plenty other examples throughout the winter imo

It's always the same with storms winding them selves up near us, it's difficult for the models to get some systems right even up to T0.

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I must be misreading the charts because I'm seeing lows tracking further south than normal, pulling in air from the east. That's not a recipe for snow?

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12 minutes ago, Paul_1978 said:

I must be misreading the charts because I'm seeing lows tracking further south than normal, pulling in air from the east. That's not a recipe for snow?

The problem is on the few days we have easterly winds on this mornings ECM the air isn't all that cold

ECM4-168.GIF?05-12ECM4-192.GIF?05-12

ECM0-168.GIF?05-12ECM0-192.GIF?05-12

Maybe some snow on higher ground but for most we're probably looking at cold rain

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16 minutes ago, Paul_1978 said:

I must be misreading the charts because I'm seeing lows tracking further south than normal, pulling in air from the east. That's not a recipe for snow?

a modified flow, the source of the air was still from the west, and as lows track further south some of the preceding air gets drawn westward - hence its not very cold. it would need a deeper easterly feed from a colder source to be cold enough for snow.

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2 hours ago, winterof79 said:

At 240z where have I heard that before this season:closedeyes:

One major lesson learned this winter.The models are becoming even less accurate beyond 120z.

I feel compelled to  agree with that. It was a fiasco between ecm,  gfs and ukmo on the January "cold spell" it's always fi and its covering the bases on behalf of the models with this latest display from them 

Edited by snowfish1

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It is remarkable, the lack of cold air to our east to be entrained into these sliding lows. The only way we can really 'win' while these lows keep cropping up south of Iceland (and I really do think the Cold Pool is playing a role here) is if we get a trough aligned such as to pull down cold air from the vicinity of Svalbard, and even then the airmass would be only just sufficient.

It is one of those occasions where it's possible to claim success with predicting the general theme of a disorganised vortex and ares of higher heights in the mid-Atlantic or Greenland, but not in terms of the potential for snow increasing as much as such a pattern implies. Nine times out of ten we'd have more in the way of cold to tap into, but after that crazy December and predominantly westerly January, the state of affairs is very much a vision of what many may think of as the 'new normal' in the sort of generally warmer climate expected some 50 years from now. For now though, it can be seen as an unusual deviation driven by particular circumstances.

 

It's with these sort of caveats in mind that I present to you today's update on the GWO projections:

gfsgwo_1.png

Again, the incoming cycle is adjusted upward to a higher AAM state, reflecting increased tropical forcing from the Pacific. To put it (perhaps too) simply, the higher the cycle, the more the chance of seeing some decent mid-Atlantic ridges (given the broad scale pattern) during weeks 2-3 of Feb, and assuming the MJO is also propagating east as expected, the greater the odds of seeing some proper high latitude blocking emerge by the final week of the month. 

 

For weeks 2-3, I can see the goal here being to displace the trop. vortex from the strat. vortex, either by disconnect or perhaps some manner of tilting in the vertical structure. The 00z GFS at +312 shows this sort of thing loosely:

npst30.png npsh500.png

...as well as the main problem we'd face, much as we're seeing in the near future, which is the threat of lows being able to smash through mid-Atlantic ridges due to the zonal flow (jet stream) still receiving some support from the strat.

It goes without saying that the exact position of the strat. vortex could be important, assuming a connection to the troposphere. Again I think back to what I now know to be Lorenzo's post (cheers Nouska) from way back on 15th Jan:

"The strat trop disconnect - fascinating this year, W1 Nino vs. the oddness of Kara and now potentially Siberia leaves a layer of the atmosphere modified not by upwelling or down welling but by other factors. Forget OPI or SAI or QBO, this year I feel brings EPF to the fore, there is a possible mode here similar to the QBO. It originates in the mesosphere so beyond our science right now, however it is there."

Incidentally, the Kara ridge continues to crop up in the model output from time to time.

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