All goes a bit flat on this run but not before plenty of cold and snow around.

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Now general idea the same as the updated n/24 22:00 weather for the week with sliding lows possible from the n/w after cold northerly outbreak at the end of this week and next weekend

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=210&mode=0&carte=1

 

JMA day 9: JAM day 9 tomorrow:

 

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crikey jff

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=288&mode=0&carte=1

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=300&mode=0&carte=1

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=312&mode=0&carte=1

 

Hmm I take back my "a bit flat" comment.

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Still looking good for some colder than average and unsettled weather.

This is the point IMO where things will go wrong if they are going to go wrong. I think by this time tomorrow if there is no downgrade I will begin to get more seriously interested.

http://www.wetterzentrale.de/maps/GFSOPEU18_90_1.png 

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Hi to all..

😂😂🌫🍂😆.

Yes or No, the prediction for the upcoming week is well disguised- What will we see this time, I am lost for words.

I know the GFS, UKMO and NAVGEM seem to be cherry picking

what we fellow nerds want to Gasp at for the Holy Grail of getting hit on our noses by the Straight North Pole Acting Arctic Northerly it bring down to us by Thursday next week.

I watch with interest for London’s sake that if it can bring snow showers here I’d be an unsung hero!.

Never say it too quickly 😀😏. Send Wednesday’s tropical depression SE to France on Wednesday night and fist 6 hours of Thursday, then show us all across UK an arctic plunge. -10 at 850 hPa by 6pm and on Friday to Saturday- we can all be patient I just pray for a need for seeing a snow settling under below freezing temperatures of -4.🔚🌎🌃🌖🌞. Ahem and ECMWF on board as well- what corker and tease!.

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Some of those have a pretty nasty storm in there

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=126

control thus far

http://www.meteociel.fr/modeles/gefs_cartes.php?code=0&ech=144&mode=0&carte=0

 

Sensational model output tonight.

Like Doc I’m still not fully on board but I will be once the low’s passage & northerly gets into the range of T+96 and sooner (this time tomorrow hopefully). 

P1 from the 18z GEFS. Just for fun. 😀😀

http://www.wetterzentrale.de/maps/GFSP01EU18_132_1.png

http://www.wetterzentrale.de/maps/GFSP01EU18_132_2.png

Might be a few snow showers 😉. 

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Aye - that's one of those either way charts. Wouldn't be a surprise if in a day or so you look at that and say it was why no cold spell was on. Jet pops up over stubborn heights to south, blocking to the North West dissipates and we end up on the mild side of the jet. Easy to see it happening.

Or on the flip side we have one of those admittedly rarer moments where you look at that chart a few months/years down the line as the start of a fun little cold spell, where all the pieces were there and for a change they fitted together well for cold.

Given the background of repeated Northerly interludes, occasional genuine Northern blocking, no organised PV and something not too far from cross model agreement for the cold to at least start I reckon we might be 'sliding' towards the latter. Whether it's cold enough for widespread snow or just wintry and those with height or in the North getting luckier with snow rather than rain is of course very debateable but it does look tantalisingly close to a snowy pattern for many. 

Of course now I've let my guard down a bit let's watch the models back flip in the morning

 

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Just as a word of caution - there a fair few obvious topplers at T+144 amongst the 18z GEFS. 

http://www.wetterzentrale.de/maps/GFSPANELEU18_144_1.png

 

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ECM 12z ensemble suite for London:

http://www.weathercast.co.uk/services/ensemble-forecast.html

 

The op was only a little colder than the ensemble mean. The mean is actually colder than the 00z beyond day 10 with maxima around 3C

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As I mentioned earlier I can hardly recall falling snow from a northerly let a lone settling snow. With such a long fetch from the north and sea temps in the Channel circa +12 what are the realistic chances of -8 850hPA air making it across the channel? GEFS 18z would have us believe that the majority of runs will bring -7 / -8 850hPA to my shores and one or two even touch -10. Somehow I doubt it!!

http://modeles7.meteociel.fr/modeles/gens/runs/2017120218/graphe3_1000_217.94000244140625_247.4199981689453___.gif 

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fwiw Joe not reflected with the mean at that time we shall see

 

 

Looks like the rain won't turn to snow on Thursday - it looks like it will peter' out and then Thursday night showers will follow and then turn wintry and then after showers will fall as sleet or snow almost anywhere - I can see a lot of this being soft hail!? Proper Arctic weather

 

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EC15 pretty much similar to this morning's output post day 10. Cool pretty much throughout with much uncertainty about Atlantic pattern. 

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Yes while a few are topplers, there are still plenty of long lasting Greenland Highs.

and some of the ones that do topple the High go on to show some ECMesque delights...

All good fun! 

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Yes, but a slightly colder mean and, related, a little less scatter on the mild side.

Some uncertainty without doubt but around a theme of cold to very cold. I’ve learned to accept that the ensembles can also flip but as it stands for now it’s not looking at all like a normal early December.

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Morning!  The GFS depicts a cold then cool but for many, dry picture out to day 10.

The precipitation in a Northerly / Northwesterly (the latter being more the ticket) is always focussed in on the extremities with Wales and the SW peninsula and the extreme East Anglian coast being favoured, But virtually dry as a bone in the middle, once the back edge sleet has cleared Thursday/ Friday, though note the "Cheshire Gap" effect visible.

Heres the picture for most of England, and Wales: Great graphics Brian, which I am slowly familiarising myself with.  p.s - how to I access your ensemble data?

 

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Yes, GFS 00z certainly has a milder long-term outlook compared to the 18z. The low pressure which is set to bring snow for many heads further north-east on this run and an undercutting low from the Atlantic is more pronounced as its heads into France and seemingly opens up a potential return to more zonal conditions, especially in the far south. So many opportunities for things to change in the meantime so its just a case of watching the output for the next two or three days to see which options firm up for next Wed/Thu which is the key date. Off to have a peak at the other models now!

Here is that undercutting low.
http://modeles.meteociel.fr/modeles/gfs/runs/2017120300/gfs-0-180.png?0 

The ensembles for London

http://modeles7.meteociel.fr/modeles/gens/runs/2017120300/graphe3_1000_305.94000244140625_136.4199981689453___.gif 

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ECM day 9 has the colder air clinging on in the extreme east:

 

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Having looked at this morning's runs, my views haven't changed since yesterday: a case of close, but no cigar for those of us in the south.

Thursday still looks pretty wet and windy and as has been mentioned it's not looking like there's much chance of a "rain to snow" event. GFS has unsurprisingly realised that a low to the east of us is unlikley to happen (as alluded to yesteday) and thus joins ECM and MetO in keeping the core of the lower heights away over Scandinavia. This gives a lower risk of snow down here and with 850s never escpecially low you'll be lucky to see much I reckon - unless, that is, you have decent altitude (which'll compensate somewhat for the uninspiring 850s).

With the low safely away to the NE, the high to the west then topples towards us - as there's nothing there to "prop it up", so to speak. However, with heights rising again to the west, the next Atlantic low gets ripped in two (at least, both GFS and ECM agree on this at the moment). The southern portion of the low ends up to our south, leaving us in a chilly col. Again, though, 850s are nothing to write home about. Should skies stay clear, frost looks likely, the sort that persists in the shade all day. If it's cloudy - well, cold drizzle or perhaps sleet.

Note though that this is all referencing the south. For the Midlands north things may just be on the right side of marginal, painting a rather different picture!

(There are two things which I'll be looking out for before I get excited. One, a decent blast of -10s or lower at 850 and two, low pressure to the due east, south or SE at a timeframe of only 72 hours out or less. When it's further out inevitably it seems to shift northwards - goodness knows why it's so hard to get a low at our lattitude immediately east of the meridian, but it is!)

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ECM has more realistic 850 hPA temps IMBY at T144 and follows are fairly similar pattern to the GFS at that stage with the initial low not hanging around and moving off into Scandanavia with an undercutting low looking to potentially introduce colder conditions thereafter, perhaps with a brief easterly, without letting the Atlantic back in!

http://www.meteociel.com/modeles/ecmwf/runs/2017120300/ECM0-144.GIF?03-12 

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Pretty good ecm not as spectacular as yesterday's 12 but still borderline snow events in the later stages for most of England . can't really complain to much.

 

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Agree with most of this, which is how I read the situation too,  Though purely academic as day 9, I think in theory,on day 9, with surface cold and a SEly drawn up as the trough slips away, with -5/6 uppers there's a chance of something wintry for the SE that day but all frankly irrelevant as things will verify differently I'm sure.

The ECM/GFS are good for high ground in the north, with exposure to the NW.

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