ICETAB

So we're in with a shot then...

Based on current output I'd say you're brave to call a week long cold spell, and I am not sure describing the high pressure at T240 on ECM as a toppler high. Is it deliberate to get a rise out of others, or is it a true belief? The bitterly cold upper and lower air filtering around the south of the high pressure ridging to Scandinavia is going to help keep it in situ. It extends west, and the likelihood of the pressure to lift north is more likely than not in my opinion.

Good to see such a deep low pressure sinking into Europe on the GFS, with high pressure building further North. I see ECM is rolling out now...

You could be right, but I'm not sure.

The ECM 240 chart is not standard fare. Lows way south and high pressure building over Scandinavia again. Looks very different to the norm. I'd say, if it did come off like that, which is highly unlikely, there is high probability of a reload down the line...

I take some comfort from this, given that it was the GEM that modeled the current west based -NAO that GFS is now showing a couple of days ago. It seems to have been picking up on new trends before the others. If it is going back the other way, perhaps others will follow suite...

Pert 17 for Xmas Eve please...

I disagree, I believe high pressure will start building around iceland on the 11th and start buliding/drifting towards greendland therafter.

I can see one member of the ECM ensembles that goes cold just after the 7th, I know it's highly unlikely that future output will start to go this way, however, people need to remember how volatile the weather is and how quickly things can change. The signal for cold has been waxing and waning over the past week and it's currently waning, perhaps the slight uptick in solar activity hasn't helped in that respect. I do believe though that it will start going the other way as we head through the weekend and suspect that cold will come as early as 11th, as initially picked up on. Let's wait and see how things pan out...

GEM looks like it might go on to produce a scandi high to me at T144!

This morning 6z has a similar evolution at the end, you never know perhaps it's a new trend.

Perhaps new thread for the 18zs?

NAVGEM maintains the cold all of the way through its run. It has an easterly at T180. Lets hope the others follow it tomorrow.

Unfortunately ECM does not build heights over Greenland like we see on the UKMO chart at 120, nor do any of the other models.

Better 850s at 144 from UKMO and ECM, -8 across a large part of the country and more direct winds from the north. T168 could be interesting, setting up for an eastly perhaps! EDIT: looking again not quite -8 uppers at 144, more like -6/7 168 is even colder but look like high pressure will be over us come 192, let's see EDIT part 2: I've seen enough, by 216 it's trying to reload the cold from the east/ North east, few adjustments and it could get there. I think this could still lead to an epic cold spell. Interesting times ahead

GEFS ensemble 7 shows the type of pattern I want to see in the future. Perhaps it's the only one that has sniffed the projected warming up in the srat. I believe we will see allot more HLB come Wednesday of this week.

I think it would be good to have a long range prediction thread. That area of meteorology is being enhanced all the time and it will help others learn about the different factors at play.

Looking at the stats we should be in a -QBO shear phase this DJF nearing a -QBO peak late winter, which should mean the polar vortex is less intense this winter.

I'm starting up a new winter thread, I know the previous one, opened around May time, was closed off because it was thought to be to early. However I think now is a reasonable time to start looking ahead to the next winter season, what with the solar cycle taking a dip and ENSO predictions firming up for autumn/winter. Does anybody have any thoughts on the matter

GEFS, members 3, 6, 9 & 19 all look good to me 3 being the best. I also note that the PV wants to migrate east on a good few runs which should make it easier for heights to build around Greenland further down the line. GEFS mem 3;

Christmas is currently looking like having below average temperatures with winds coming from the north west? I find your post a little misleading...

When did it happen, today?

NAVGEM looks interesting at T114 on the 06Z

I thought he posted something about the ECM32 dayer yesterday that suggested december showed Northern blocking. Does that not mean the first month of winter will have a -NAO?

The BOM and ECM looking cold all the way through! I love the look of the last frame of the BOM. I think it could go on to show another easterly, except when it evolves this time it will drag down very cold air. Winter could be interesting. ECM brings more cold at T216 as that low out west goes under the block. 850s stay low enough for snow to lower levels at T240