Model Output Discussion - Spring Has Sprung

[Ali1977]

 sheikhy and fir cherry picking P29 looks good for Thurs onwards too - in fact it’s pretty awesome 

Meteociel - Cartes Ensemble GFS (ENS/GEFS)

WWW.METEOCIEL.FR

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meteociel propose des rubriques météo temps réel, forums, modeles...

 

Edited February 6 by Ali1977

[February1978]

Good to see a southward trend of the models, much better for longevity through February.

Meanwhile, whilst we’re all wondering where the ‘snow line’ is going to be on Thursday, it’s worth remembering that in these global models 50-100 miles is quite a small distance - but for us it could be a huge deal.

Expect ‘small’ changes right until the end & enjoy the ride……!

[Ali1977]

How should we rate the ARPEGE and AROME at T48 ? 

[Sweatyman]

 Ali1977 clearly right!

[Lukesluckybunch]

1 minute ago, Ali1977 said:

How should we rate the ARPEGE and AROME at T48 ? 

It has it north of m4 event

[Purga]

Alle - flamin - luia - always Mañana though...

[feb1991blizzard]

 bluearmy

I am usually massively in favour of splits but on this occasion, i can't see how after the displacement we get the w2 through Greenland to Pacific and safely get cold in as the vortex needs to get back over the pole first (fraught with danger) , the problem is (as you can see in T216 charts) is, we need a N'ly first to get roper cold into Europe, then we need a mechanism for it to head west, i'm struggling to figure out the synoptics at the moment (doesn't help not having GFS strat height charts for a while now mind)

[carinthian]

Oh the vagrancies of the GFS op. Still showing the warm side of the mean values.  Looks well off target. However, not as warm as over here , 21.3C recorded near Graz yesterday , beat the previous record by a massive 3.7c ! Now as promised earlier have some latest results  from the Super HD 4x4  snow model with specifications  for the British Isles.  Looking at the parameter 0-25cm snow depth with location at Sea level for 12noon on Thursday. Aprox Birmingham- Peterborough  -Galway- Dublin with northward extend to South Cumbria and Northern Ireland border country. Values at sea level 1-2cm in south of zone and 2-5 cm  further north. Heaviest depths of 25 cm  in Southern Pennines/ Peak Distric, North Wales , especially above 200m and higher parts of Eire to the west of Dublin.   This prognosis only goes to 48 hours , so cannot provide results where snow turns to rain. However, I think these results could indicate a limited on the Northwards extent.?

C

Edited February 6 by carinthian

[Ali1977]

 carinthian Birmingham to Peterborough would suggest a southward movement compared to what the UKMO/GFS/ECM are showing - maybe the Arpege and arome 06z are onto something

[bluearmy]

 feb1991blizzard

Weather is cool

WWW.WEATHERISCOOL.COM

GFS 10mb Geopotential Height -- Instant Weather Maps

WWW.INSTANTWEATHERMAPS.COM

 

[feb1991blizzard]

 bluearmy

Oh they're back - thanks.

Interesting chart right up top.

Edited February 6 by feb1991blizzard

[johncam]

The problem is any snow away from high ground won't last a jot,  850's and ground temps aren't cold enough. 

[UnderTheAnvil]

 Ali1977 Been looking at them on Windy, the ICON seems to agree with the AROME too. In summer I always look at the AROME a couple days out before a Spanish plume to see how they play out, and it always seems to handle that well. Fingers crossed that it handles snow well too.

[Rain All Night]

11 hours ago, Rain All Night said:

12z deterministic runs, Tue 6th to Mon 12th (day 7)

As of this afternoon, the last remaining model showing a flatter and more southerly-tracking low for this week has dropped that solution, so the next question is what the low will do after it reaches us, with ECM and GFS both currently sending it northwards, which would be a disappointing solution if correct; other models show it moving east, northeast, or simply filling in situ over the UK.

By day 7, the charts are again messy as has generally been the case for the past several runs, but one thing that seems to be generally agreed upon is the appearance of the next Atlantic low to the east of Newfoundland. Normally I'd be worried about whether that low might soon be coming to steamroll over us, but the ensemble means I've shown further down this post suggest to me that this is not going to be the case. The GFS currently stands alone with its suggestion of mild southwesterly winds being pushed up by high pressure returning over Iberia.

12z ensemble means, Tue 6th to Tue 20th (day 15)

As mentioned above, it doesn't look like that next Atlantic low is going to make it as far as the UK. A couple of days ago, the build of heights showing on the ensembles looked as though it might become an Atlantic ridge. Then it briefly looked like it might instead be a Scandi high, and now it looks more assuredly like a UK high, with a chance of it subsequently retrogressing to a Greenland high, which I'm sure many here will be hoping for (and without any delay!)

As a fan of dry synoptics, I'm pleased to see that high pressure should be returning for mid-month.

0z deterministic runs, Tue 6th to Tue 13th (day 7)

The second Atlantic low struggles east and pushes the mess left behind by the first low (the nature of this mess is still unclear, a mixture of weak low and weak high pressure) up over us. ICON is now showing the mild southwesterly air flow at the end of the run that GFS was showing yesterday afternoon, but the ensembles shown further down this post suggest to me that this will not verify.

0z ensemble means, Tue 6th to Wed 21st (day 15)

The models still agree that the second Atlantic low will not reach the UK. Mid-run, the highest mean pressure on the surface has reverted to being over Scandinavia rather than the UK, although a cold air flow into the UK is not suggested. In the later stages, the mean heights in these runs are noticeably lower than they were last night, especially on the GFS and GEM where an Atlantic return is looking imminent by 21st February, and the signal for high pressure migrating to Greenland looks significantly diminished.

Edited February 6 by Rain All Night

[Dennis]

10hpa from midmonth

Edited February 6 by Dennis

[AO-]

My first impression of the GFS is that it has a more sensible outcome than before and that the bigger picture fits the evolution wrt background drivers more. That it doesn't deliver instantly is a pity, but this is imo the right direction of travel. Honestly I would like the shortwave to track east quicker, but none of the models are showing that. Nevertheless Synoptics to look forward to despite the fact that the cold (especially for Britain) gets a little postponed. The u-turn GFS had made since yesterday shows for me the superiority of EC atm although EC doesn't have nailed it perfectly either. 

Edit: To visualize the above: for here the operational fits the EPS perfectly whereas for Manchester its kind of an outlier. This shows the complexity of the current situation. 

Edited February 6 by AO-

[Lukesluckybunch]

Ec 30dayer looks cold and blocked all the way...especially next weekend onwards..prevailing east/northeast winds

[carinthian]

 Ali1977 Quite possible. I think snow could lie for a time Birmingham -Peterborough on Thursday morning before the Arctic air is replaced. However, with the Northern Limit shown to be a bit further south could indicate doubt in the battle zone perimeters.

C

[E17boy]

Just a quick question wishful thinking. This Thursdays snow event, is it at all possible that if the colder air makes more of a fight the snow and could move south and put us down here in the South with some chance. I know it’s dream thinking but is that at all possible, bearing in mind it’s a evolving situation and things are changing every few hours.

regards 

Should have said above that the front pushes south with back edge snow as the cold undercuts. 

[Lynxus]

 E17boy I highly doubt it will get anywhere near the south.

Gfs has the 850's north of Birmingham at the best of times, so id be shocked if it even reaches south of where I am in Gloucester.
Almost zero chance of it reaching near the M4 if I'm honest.




WAYYYYY out in FI there's a hint of a northerly. But again i doubt it will look like this

Edited February 6 by Lynxus

[E17boy]

 Lynxus Thanks mate just a shame the cold undercut is not strong enough to push that snow and further south. The waiting goes on here in London 

[BLAST FROM THE PAST]

I’m liking the synoptic development of the 06z a lot….and as crazy as it sounds it’s a run that is pretty much on my money.   Timings look pretty good too.  Icon and 06z GFS sliding the LP into near continent is how I saw and still see it.  Then where the GFS heads to in deep FI….yep I like it and ‘generally’ how I think it will pan out.  HP moving north/ NW settling there with troughing to our E /SE = cold to very cold with chances of snow aplenty…..Our winter is arriving it would seem.

 

BFTP 

Edited February 6 by BLAST FROM THE PAST

[BLAST FROM THE PAST]

 E17boy  I think be prepared/of mindset we miss out, but if the LP does slide E/ SE as I anticipate then there is a chance the snow will shift southwards as it clears.

 

BFTP

[E17boy]

 BLAST FROM THE PAST Yes would be nice but chances looking slim at the moment but subject to change as always. My attention now focussed on whether we can get this Scandi HP and E or NE winds. Time is ticking but all to play for anything can happen come mid Feb. This would be the perfect setup with convection from the North Sea. My fingers are crossed just need the blocks to fall in place.

[That ECM]

Been mad busy so just catching up on output. Not sure if this has been posted. Interesting.