Winter Model Discussion 18Z 3/2/13 onwards.

[Ryan Dutch Weatherman]

Ok Great Brittain, you see , i told you , this is snow bom for you.

Now i go update for my own country . End after that i go sleep.

Ciao , i come back in night again.

[winterof79]

I expect bedlam to break out once people see that UKMO 144hrs chart, looks like that cold pool to the east gets pulled west into the low as it clears, could be significant snow off that.

The GFS is a big improvement from yesterdays runs, that key upstream eastern USA low which the ECM deepened against the consensus looks like being the right call.

Not as much bedlam as when they see this matching it

http://www.meteociel...1-144.GIF?05-12

http://www.meteociel...44-21.GIF?05-06

Edited February 5, 2013 by winterof79

[Jason M]

Well, looks like game on this morning.

GEFS are absolute carnage this morning. Pretty much zero agreement at day 6! Amongst the other models though we now have agreement for a pretty decent cold spell.

To my eyes its still not 1991, but another little uptick this morning in terms of severity. I think on what's shown we might match the last cold spell. I certainly prefer the upper temp profiles compared to what's been shown of late. We seem to have a slightly better cold pool to work with.

Jason

[Mucka]

Could be shortlived on ECM though with the pattern fairly flat behind and the spoiler shortwave that popped up on GEM is in evidence on the 168 chart.

UKMO is actually the best model for sustained cold this morning. ECM will need another slider.

Edited February 5, 2013 by Mucka

[Ian Brown]

Well anyone who saw the GFS 18Z unfold last night won't be surprised by it's further shift in position this morning, quite good agreement between the other models for the slider at T120-144, although the ECM looks to quickly be bringing the Azores High and therefore the Atlantic back in by T168 - as it develops our old friend - the Norwegian coastal shortwave which prevents the Scandi heights edging West.

Edited February 5, 2013 by Ian Brown

[cooling climate]

Looking very snowy this morning on the UKMO and ECM t144 charts. In fact a major snow

event if it were to verify although at six days out the adjustments will take place in the track

of the slider low but some parts of the country are going to see a lot of snow I think.

[Ian Brown]

Atlantic back by day 8 and the jet is very strong to the NW - days 9 and 10 won't be pretty.

[winterof79]

Well anyone who saw the GFS 18Z unfold last night won't be surprised by it's further shift in position this morning, quite good agreement between the other models for the slider at T120-144, although the ECM looks to quickly be bringing the Azores High and therefore the Atlantic back in by T168 - as it develops our old friend - the Norwegian coastal shortwave which prevents the Scandi heights edging West.

Cue slider no 2 waiting in the wings http://www.meteociel...1-192.GIF?05-12 he says awaiting 216 which does not.

Edited February 5, 2013 by winterof79

[cold snap]

morning .

Ukmo going with the ecm at the 144 timeframe.

Could be shortlived mine.

Gfs still not there

ukmo is epic must be said.

[bluearmy]

The norwegian shortwave on gem and ecm is not the same feature. Gem drives it out of the euro trough whilst ecm drops it in from the north. Whichever way it arrives, it will curtail the duration of cold as it prevents the russian ridge from extending west. This really is the evidence we require that the spell will not last too long. However, all the neersayers did not see this feature and just got 'lucky' as is the way with uk winter cold spells. The atlantic will invarialy win - the cold has too many hurdles to jump over. In the meantime, prospects of a good old weekend blizzard!

However, at day 6, it may not repeat the same way on the next run and the ens may not pick it up too well.(second edit- ecm drops in at day 5 so not looking good imo unless it can correct it east so it gets caught in the flow with massively different results)

Edited February 5, 2013 by bluearmy

[Duane S.]

Very nice upgrades this morning from most models, including the GFS. Yet to see a strong signal for longetivity but time for that to show its hand over the coming days

[Ian Brown]

Cue slider no 2 waiting in the wings http://www.meteociel...1-192.GIF?05-12

No, heights have retreated to the NE, the jet will get through and heights will rise to the South.

[MR EXTREMES]

Not as much bedlam as when they see this matching it

http://www.meteociel...1-144.GIF?05-12

http://www.meteociel...44-21.GIF?05-06

indeed incredible but i will say in the longer term its knife edge stuff the only thing i can say is the cold spell just recently to a lot of budging once cold is in place your notice how it holds on so anything beyond t144 i would certainly say fi.

but that nice blob on heights right over the pole and just northesat of greenland looks lovely.

[swfc]

Atlantic back by day 8 and the jet is very strong to the NW - days 9 and 10 won't be pretty.

not making threw tho ?

[MR EXTREMES]

Atlantic back by day 8 and the jet is very strong to the NW - days 9 and 10 won't be pretty.

certainly not blowtorch but as i said this pattern will change it will be a much slower breakdown.

[Mucka]

The norwegian shortwave on gem and ecm is not the same feature. Gem drives it out of the euro trough whilst ecm drops it in from the north. Whichever way it arrives, it will curtail the duration of cold as it prevents the russian ridge from extending west. This really is the evidence we require that the spell will not last too long. However, all the neersayers did not see this feature and just got 'lucky' as is the way with uk winter cold spells. The atlantic will invarialy win - the cold has too many hurdles to jump over. In the meantime, prospects of a good old weekend blizzard!

It's pretty much the same feature since it is born from the Euro trough, just handled differently. It forms to the NE as you say and moves west - it doesn't drop down from the North.

[MR EXTREMES]

certainly not blowtorch but as i said this pattern will change it will be a much slower breakdown.

the gem has a similar setup to the ecm at the end but difference is the ecm has a more robust bloke in place and once again the azores heights make it a stale mate right at the end of the ecm run notice i said at the end still some exciting weather to come.

[winterof79]

No, heights have retreated to the NE, the jet will get through and heights will rise to the South.

Yes edited my post Ian.No doubt it will change again before then.As BA posted, some good old fashioned weather to come first.

http://www.meteociel...1-144.GIF?05-12

Edited February 5, 2013 by winterof79

[MR EXTREMES]

The norwegian shortwave on gem and ecm is not the same feature. Gem drives it out of the euro trough whilst ecm drops it in from the north. Whichever way it arrives, it will curtail the duration of cold as it prevents the russian ridge from extending west. This really is the evidence we require that the spell will not last too long. However, all the neersayers did not see this feature and just got 'lucky' as is the way with uk winter cold spells. The atlantic will invarialy win - the cold has too many hurdles to jump over. In the meantime, prospects of a good old weekend blizzard!

However, at day 7/8, it may not repeat the same way on the next run and the ens may not pick it up too well.

and is it likely to take this path or will it happen or not this is the million dollar question its knife edge but atleast were getting somewhere and things will change but yes i do agree uk does have issues with bloody shortwaves blocking the block lol but it could be different by tomorrow.

[nick sussex]

Oh well if its to be that pesky shortwave that strikes the fatal blow to the cold then at least before that it goes out with a bang with that snow event at 144hrs.

Unfortunately once that shortwave appears its downhill from there as that allows too much energy eastwards and its beyond repair at that point.

We'll see if that shortwave does verify, hopefully not but certainly its an unwelcome addition to a generally positive start today.

[MR EXTREMES]

Oh well if its to be that pesky shortwave that strikes the fatal blow to the cold then at least before that it goes out with a bang with that snow event at 144hrs.

Unfortunately once that shortwave appears its downhill from there as that allows too much energy eastwards and its beyond repair at that point.

We'll see if that shortwave does verify, hopefully not but certainly its an unwelcome addition to a generally positive start today.

that shortwave could also be our friend if it can get futher west.

Edited February 5, 2013 by model rollercoaster

[Ian Brown]

Oh well if its to be that pesky shortwave that strikes the fatal blow to the cold then at least before that it goes out with a bang with that snow event at 144hrs.

Unfortunately once that shortwave appears its downhill from there as that allows too much energy eastwards and its beyond repair at that point.

We'll see if that shortwave does verify, hopefully not but certainly its an unwelcome addition to a generally positive start today.

Yes I would advise members to enjoy what may come over the next day or so and then the weekend because if the ECM verifies in the later stages it would be a long way back to anything cold after that and obviously T240 is the middle of Feb.

[winterof79]

So what would happen next as there is no zonal train awaiting.The lobe of what is left of the PV is going to hit a brick wall and i would say it coul drop down to the e/ne of us.

http://www.meteociel.fr/modeles/ecmwf/runs/2013020500/ECH1-240.GIF?05-12

Not sure if GP mentioned somethig regarding a section of the PV.

[MR EXTREMES]

Yes I would advise members to enjoy what may come over the next day or so and then the weekend because if the ECM verifies in the later stages it would be a long way back to anything cold after that and obviously T240 is the middle of Feb.

of coarse ian there was always the chance the alantic would break through and by far its not the end for winter just yet and that once again this is one run and as i stated t144 and beyond is fi even though the ecm has performed very well against the gfs the shortwave has reared its ugly head now but we shall see because im not convinced that this shortwave will be there after a few more runs.

[nick sussex]

that shortwave could also be our friend if it can get futher west.

No we want it gone completely, because of the set up you need the Russian high backing west to put some forcing on the next upstream low to disrupt.

The shortwave stops that and then really its game over from there. As Ian B says which I agree with its a long way back to cold from the ECM later output, anyway before that theres still alot of weather and could be a big snow event at the weekend.

We might still see some changes to the placement of the shortwave or preferably the ECM is doing a GFS special with that!