Yeti

Interestingly on weather forums in Germany (wetterzentrale forum) and Spain people tend to look at the GEM and GME a lot more than we do - I've always found the GEM a good, reliable and consistent model and it's a shame we don't look at it more often (and no that has nothing to do with today's output! ) Trust the Brits to favour the American and British models

Good point. Temperatures have risen over 20c here from -16 to 4 in just a few days - the cold spell has gone entirely from virtually all of Europe except the northern half of the UK. This would not necessarily be a problem if, like last time, the cold air were to come from the E, as Europe cools down BEFORE the UK in such setups. However cold air is arriving from a *shallow* cold pool over Scandinavia to the N/NE of the UK and Europe should actually cool down after the UK this time: http://www.wetterzentrale.de/pics/Rtavn962.png http://www.wetterzentrale.de/pics/Rtavn1682.png The only potential problem with this is if we see this kind of setup: http://www.wetterzentrale.de/pics/Recm2401.gif Normally this would bring widespread blizzards along the "battle ground" with a strong SE wind blowing off the continent. However as upper temps tend to be higher in these setups, ground temps need to remain favourable to prevent rain, and if the continent is not cold enough this may not happen. Of course if such a setup occurred later on, like the ECM, there would be no problem, but the UK will probably have to wait until the cold air filters S for widespread low-level snow from a setup like the above. Here's hoping the low tracks as far S as possible - this would favour everybody!

http://www.wetterzentrale.de/pics/Rtavn3001.png This must be one of the most exceptional charts the GFS has ever produced! Iceland is freezing with snow showers, Scandanavia is frigid and a huge snowstorm sits over the UK, the Low Countries, Germany and the Alps. We can but dream

Wow, you have more snow than we have here in Bonn. Nice pics

Well the cold spell is drawing to a close here tomorrow after a week of consecutive sub-0 maxima. This weekend I have been out to take a few photos near home - firstly of an extinct volcano in the Rhine Valley (Saturday) and then of Ahrweiler (Sunday), a small town about 20 minutes away with a famous wine and liqueur tradition. The weather has been exceptionally cold - a cold front on Friday brought sub-20 uppers and that translated to a maximum of just -12.1c here and -11c in Bonn on Saturday. At night temperatures dipped below -16 although other parts of Germany saw clearer skies and even colder minima with -33 reported in one area. The cold was incredible - your nose completely freezes up and more than 10 minutes outside, even with proper winter clothing, is enough to chill you to the bone. As for snow, Friday brought light to moderate snowfall for a while but it was proper powder snow falling at those temps, so it accumulated very quickly. Yesterday brought another 2cm so overall about 8cm here which would have been a disappointment had it not been for the extreme cold which made up for it Here is a photo of a nearby road leading to the volcano: Inside the crater, snow covers the lava-formed rocks: The view towards Bonn, Cologne and Düsseldorf from the top. The shining building contains the headquarters of Deutsche Post and DHL. The Siebengebirge, our nearest range of hills, through the vineyards. The Rhine is visible at the bottom: The Christmas markets in Ahrweiler - a Dickensian scene! It then starts to snow: Icicles have formed on the market stalls: Enjoy

Glad to hear plenty in the N have got snow. I'm so annoyed here missing out with just a dusting!

It's such a shame - there's such a huge easterly just a few hundred miles to the N! http://www.wetterzentrale.de/pics/Recm1681.gif

Actually that's something I had noticed, quite a lot of the models are hinting at pressure and even height rises over Scandinavia later on, and whilst this might not necessarily lead to a full easterly reload it would at the least make the cold air harder to budge. GEM: http://www.wetterzentrale.de/pics/Rgem2281.gif UKMO: http://www.wetterzentrale.de/pics/Rukm1441.gif ECM: http://www.wetterzentrale.de/pics/Recm2401.gif As well as the nice GEFS members you posted Obviously not all of those would lead to cold in the short term but seeing heights and pressure to our NE is rarely a bad thing! On the other hand this would need to occur late enough so as not to prevent the Atlantic low moving far enough NW.

The cold is cruel here Nick - temps refusing to get above -3 today, with -9 maxima predicted on Saturday! http://www.wetterzentrale.de/pics/Rmgfs574.gif That could definitely be one of the coldest days I've ever experienced, certainly at home. Sadly the Euros still want to send the low further W atm and so it's GFS/GEM vs ECM/UKMO. Mind you, I believe the 6z was the first GFS run to send the low at this angle? I don't remember seeing it before because a warm up looked almost guaranteed here by next week with no models showing anything more favourable e.g. 6z.

I'm still amazed by the sudden short-term changes on this run. http://www.wetterzentrale.de/pics/Rtavn482.png The -15 isotherm was expected to reach no further than East Germany yesterday. On the 6z it reaches into France and the Low Countries only 48 hours away! That's a monumental shift at this range.

The 6z is very similar to the GEM which I posted earlier: http://www.wetterzentrale.de/pics/Rtavn1501.png http://www.wetterzentrale.de/pics/Rgem1561.gif The low heads NE into central Europe - this helps to keep the colder air over the UK as it lies on the western flank, and also it keeps northern continental Europe cooler which is a welcome surprise here!

http://www.wetterzentrale.de/pics/Rmgfs634.gif That's serious cold in Germany! The GEM is nice because one of the Atlantic lows instead swings further NE through central Europe and misses the UK, keeping it cooler for longer and if anything dragging down a bit more cold air: http://www.wetterzentrale.de/pics/Rgem1561.gif There are also suggestions this morning of weak pressure rises over Scandinavia in FI. Tentative, but there on ECM, UKMO and GEM to varying extents - I don't know how this fits in with the teleconnections? For example on the UKMO we see a cold pool underneath a HP cell moving SW towards Europe: http://www.wetterzentrale.de/pics/Rukm1441.gif

Now if that isn't a snow dome over Bonn I don't know what it is!! http://www.wetterzentrale.de/pics/Rmgfs72sum.gif So disappointing really that despite absolutely bitter temps here, everything is so dry. It's encouraging to see the ECM want to maintain heights to our N - the GFS has hinted at this at times as well. That would make it a lot harder for the col air to budge and would delay any breakdown until after Christmas. Meanwhile, the UK looks like getting pasted starting Thursday night - so enjoy and let's hope some people see some really deep snow this weekend.

Amazing, then a "Hogmonay blizzard" to finish! http://www.wetterzentrale.de/pics/Rtavn3721.png Incredibly snowy run, that would be 1947 equivalent in terms of depth of snow and severity of cold! FI

Looks like the cold air is winning on this run?! http://www.wetterzentrale.de/pics/Rtavn1501.png There is less energy in the Atlantic so the GL HP can ridge S more; there is also more energy in the northern arm of the jet helping the low to dig down S: http://www.wetterzentrale.de/pics/Rtavn16216.png This in turn though would probably be the death sentence for the block...

http://www.wetterzentrale.de/pics/Rtavn901.png Just look at the amount of shortwaves in the flow! It's a shame it's turning out to look a bit messy.

There is an ignore poster function, it's somewhere in settings. Jed - I think all people are saying is fair enough if it's what the models are showing but if you're going to comment on them then post the relevant charts/data. Posts without given evidence are difficult to follow, look rather too like opinion and are often less convincing as a result.

The colours represent the geopotential heights though at 500hPa so that's not WAA; the yellow would indicate very strong heights whereas the blues show troughs and lows higher in the atmosphere than can be detected at sea level. But yes as you say later on the heights crumble and move west to give a -ve NAO that sets up too far W (current pattern subject to change).

What's all this about WAA? As I understand it stands for Warm Air Advection - now that happened a few days ago up the Eastern Seaboard as the block was carved out, but for example by the time we reach 120 there's no warm air advection anywhere near GL... http://www.wetterzentrale.de/pics/Rtavn1201.png

Interesting precipitation amounts here at 144: http://www.wetterzentrale.de/pics/Rmgfs144sum.gif Given that most of that would fall as snow - particularly in the North - there are some pretty impressive totals there, especially in the NE. Obviously only a very rough guide but I think it highlights roughly how the distribution of precipitation will fall.

144 is an amazing chart - an ice day almost everywhere with blizzard conditions in the Midlands and South and Arctic sunshine with sub-5 maxima further N: http://www.wetterzentrale.de/pics/Rtavn14417.png http://www.wetterzentrale.de/pics/Rtavn1442.png http://www.wetterzentrale.de/pics/Rtavn1444.png http://www.wetterzentrale.de/pics/Rtavn1443.png

It's funny you should mention melting from underneath - I'll never forget the disaster of March 10th 2006: http://www.wetterzentrale.de/pics/archive/ra/2006/Rrea00120060310.gif Heavy snow was forecast for the North for most of the day - however the reality was moderate snow falling all day, settling on the ground for a few minutes before the sludge beneath it engulfed the fresh whiteness. DPs remained just above 0 all day in Harrogate and humidity was high due to the Atlantic air sweeping in on top of the embedded cold. The day was an all-time disappointment and the memory of it has haunted me ever since. Those sorts of setups can go either way...

Nice to see the shortwave pulling away to the SW on the 18z - it pulls in the ENE'ly feed much better afterwards than the 12z. http://www.wetterzentrale.de/pics/Rtavn961.png The cold air is a fair bit closer - watch the gates open... http://www.wetterzentrale.de/pics/Rtavn962.png

GEM 120 is disappointing for the UK: http://www.wetterzentrale.de/pics/Rgem1201.gif The high ridges too far E and the troughing is mainly directed into central and eastern europe. Still, 18z on its way...

Any sunshine would feel very Arctic I should think with high pressure, very low temps and thicknesses: http://www.wetterzentrale.de/pics/Rtavn1743.png This producing some scarily low maxima over Europe! http://www.wetterzentrale.de/pics/Rtavn17417.png Frost fair on the Rhine maybe?!