chris55

It's only one persons view though, which is fine, just important to have other opinions thrown in.

Thats a bit dramatic is it not? UKMO similar to where ECM went this morning ( have a look at the 00z) and also ties in with what Ian F has been saying regarding a milder blip come the weekend. However IMO substantial pressure rises to the north and east are the most likely outcome in the end, as Chionio says, it's just how we get there thats the issue.

P4 is a bit of a peach in hi res, in fact the whole run is pretty epic.

Ian what does MOGREPS stand for? I always think it sounds like something from Harry Potter!

UKMO raw output certainly in line with that Ian, Interesting regarding Scandi high/south-West incursions though. I like the sound of that!

06 has the Short-wave and the Tropical Low bumping into each other and joining up, I did wonder if this was a possibility earlier this morning. Although no support from other models at present, lets hope the 12zs follow suite. Depending on the track of both these Lows this "could" turn into quite a potent little feature with all that energy mixing. And if it runs just right snowfall is a real possibility. 987 Centre Chilly 850s on it's northern side A little further north and that could be a blizzard for the south.

As Mr Hugo said ens mean on ECM looking good

Models starting to struggle again this morning in the mid term, should be fun watching all the different solutions being thrown out. That Tropical wave at 144 gets kicked north on the Western side of the high on both the GFS and ECM, but how far north the ridging high gets and potential split flow over Western Greenland is undecided.

To many options on the GEFS 18z, confidence Low in any outcome as well at the Operational. Although looking more into FI a fair few do create a good block to the east.

How that Tropical wave interacts with the Atlantic high is crucial, if it stays West then the ridge is amplified like GFS ECM has it slicing through the high cutting off the extended ridge This completely changes the outcome with ECM allowing energy over the Greeny ridge whilst GFS links with heights to the north and east cutting of the Atlantic to the north. http://www.wetterzentrale.de/pics/Rtavn2161.png http://www.wetterzentrale.de/pics/Recm2161.gif How this is finally dealt with in the shorter term is crucial.

GFS 18z The elongated ridge at 192 stretching from Western France all the way up to Iceland is interesting, these sorts of high pressure ridges often are a precursor to something from the east evolving. http://www.wetterzentrale.de/pics/Rtavn1921.png Also remarkable consistency from the GFS in the last four runs, this is one area where I do rate GFS, it can be very good at picking up trends in FI if we see consistency from the Det. I wouldn't be surprised to see this theme continued over the next few days, it may well drop the idea from run to run but will be interesting to see if we get ens on board etc over the coming days.

Hi Chiono, I'm not sure at what height the chart above you posted is for, but from a laymen's point of view is the 12z FI GFS a good representation of such a split? (or is the above chart directly linked to the 500hpa chart?)

I think the chances of actually getting a cold easterly in are higher looking forward at the moment, than they were when we were looking at this weekend last week. If that makes sense.

That little southerly tracking Low is going the wrong side of the ridge at 168, we need it up the Western side and were away, Edit, but as Steve says it should just fill to the south and then we might get the ridge, we need the one behind it up the Western side though.

Just to those viewing the thread who may be new to model watching. That GFS 384 chart IS pure fantasy. There is a growing signal for the colder spell to continue and December as a whole does look like it will be colder than average, but that aforementioned chart is an extreme version of cold conditions. That's not to say it 100% couldn't happen but at this range it's merely pretty colours on the screen, bring this chart down to T120 and have other models supporting it and we may have some confidence it would verify. But the joys of the model output thread means we can speculate and fantasise about such synoptics.!!!!!

If Calsberg did model runs for the lead up to xmas.....

Anyone order a Scandi high?

This would feel a bit chilly, big windchill there,

GFS 384, Epic synoptics!

Temperature struggling to get above freezing on the De Blit ensembles beyond day 5 I reckon (we'll see when they come out) and it'll show pretty dam cold for London as well. Will be interesting to see where the Det sits in the ensembles overall.

I don't think the models have been poor, it's just that we are in a more difficult period of forecasting than a Zonal flow would be. Post 96/120 is always less certain but in this situation it's even more open to changes.

ECM 144 on Wetter, do those little kinks represent a front?

No

I'm liking the ECM 120

Looking at the GEFS to see how the individual runs deal with this Low there are many options. (more than I have highlighted here) Snow event! Misses to the south, Ridge building ahead,