I think there is a problem with the GEFS on Meteociel. The chart is showing a 2640% chance of snow in London 🙂

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That’s nothing - it’s close to 13,000% in north Norfolk tomorrow ....

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http://www.meteociel.fr/cartes_obs/gens_display.php?x=&y=&run=18&ville=Londres&lat=51.5085&lon=-0.12574&runpara=0&type=0&ext=1 

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http://www.meteociel.fr/cartes_obs/gens_display.php?x=&y=&run=18&ville=Londres&lat=51.5085&lon=-0.12574&runpara=0&type=0&ext=1 

And it's that warmth which - via Miles extension - is bringing this week's northerly plunge.

If you're a coldie, a warm Greenland is a godsend.

Meanwhile it's interesting to see just how violently the 18z GEFS lurched in favour of cold, a reminder (if any were needed) that entire ensemble suites can swing with a single run. I daresay there'll more more lurches ahead!

 

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GEFS 00z paints a generally less cold theme into next week than the 00z but the Op and Control continue to project another cold northerly in the 7-10 day period with 850hPA air between -8/-10 over much of the country. However, the uncertainty remains and from the middle of next week there is plenty of scatter amongst the ensemble members. GEM shows what happens if the High holds on across the S/E of the UK and the northerly is kept at bay.
http://modeles7.meteociel.fr/modeles/gens/runs/2017112900/graphe3_1000_311.94000244140625_135.4199981689453___.gif

 

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Decent runs from GFS and UK......ECM doesn’t seem interested at all

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What is ECM upto?
Decent UKMetO though more twists and turns to come for sure.

Based on recent runs and this morning’s day 9 chart it is playing with the idea. Time will tell...or perhaps the 12z ECM 

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lol Jacko.....who knows 

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Some chilly runs, to be sure, but I don't see any sign of the deep cold needed for a prolonged period of snow lying (away from the mountains)

See, for example, the temp anomalies for eastern Europe. http://www.wxmaps.org/pix/temp4.html 

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I would have thought that ECM 240 chart would lead to a decent northerly. 

Meanwhike the GFS op run ends the northerly rather sooner but eventually serves up a proper easterly at the end! Lots of eye candy but we are still clueless. 

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You posted an excellent comparison yesterday, showing why ECM at t+240 is fantasmagorical.

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The main problem is we don't know what that low pressure coming out of Canada will do. If it stays relatively shallow and further south then it should prop up the block to the north and also help lower heights to our south. If it deepens and pushes through over Iceland as in the ECM then it will cut off the lower part of the block and force it over the UK.

If the heights can rebuild behind it then we could still get a route to cold as the deeper low merges with the Euro trough but it would be delayed by a few days, leaving the door open for more visits from a certain 90s Radio 1 dance DJ.

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Also I'm not sure we can call UKMO "decent" at 144 hours as it seems very close to the ECM. But it doesn't cover far enough west to really see what is happening with that crucial low pressure.

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I'd still prefer that anomaly map, with the blues over western Europe and the reds over the east, to the opposite way around.

It's also notable how rapidly low temperatures travel westwards in week two.

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Here you go:

http://www.meteociel.fr/modeles/ukmo2.php?nh=1&ech=144&carte=1021

 

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Looks like a good alignment to me - that will build the Greenie HP for sure.

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Even I'm feeling some general optimism, particularly for around 6-9th December although that does rely heavily on GFS ensembles although not too worried about UKMO which isn't really in range yet.

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