Model Output Discussion - 28th November

[Nick F]

Still its not to shabby at 120.- nicely amplified.

Looks to me like an inevitable losing battle to the Atlantic early next week ... though 12z GFS and UKMO more progressive than ECM with the return to westerlies.

[Cheese Rice]

What gives you that impression TEITS? I would really appreciate it if you could explain what makes you thing cold e,lys could occur. Thanks GSL

Slider low pulling in an easterly etc there's plenty of opportunity for a NE/Easterly.

When you consider we should be seeing a more amplified pattern in the mid term added by a large pool of cold air to our north east it shouldn't be too long before we finally see something alot colder.

[Catacol]

Yes the models seem to be going against the grain with regards of what the telecons/500mb charts showing. Unless there is a major flip or as GP and JH said earlier about the models might not have the pattern correct/cold outbreaks from n,ne,e, then the trend is for cool unsettled weather after the next 4/5 days with no prolonged cold insight.

The whole crux of this ongoing "thread of gloom" would appear to be on the definition of "prolonged cold." I stick by exactly what I posted yesterday: take out the zipping low at the start of next week and the outlook IS cold. However its not Siberian Cold - posters on here need to get their radar set right, and recognise that ice days at the end of Nov and early december are extremely uncommon. The fact that we have signals suggesting ongoing blocking, with a vortex strong enough even in its split state to through sliding lows at us (as per the EC32 reported on this forum yesterday) is very exciting indeed... and a whole different sort of "cold" to the lobe of vortex on a northerly that dropped over us in Dec 10.

Temps will hover in low single figures with frost at night for the foreseeable future... and the chances in the medium term of a slider low triggering an easterly look to me to be very good. Certainly higher than your average December anyway!

So - let's have some perspective?

[Weathizard]

ECM isn't bad at 144, not a disaster but I'm worried about the lows being spawned out around new foundland area, think the Atlantic might fire for a temporary time and for us who are already saturated that's of concern

[TEITS]

What gives you that impression TEITS? I would really appreciate it if you could explain what makes you thing cold e,lys could occur. Thanks GSL

Combination of pressure remaining relatively high around Svalbard, Jet aligned NW-SE, nice cold pool just to our NE.

[Cheese Rice]

Great chart. PV split into four different chunks.

Notice the southerly tracking low too.

Edited November 28, 2012 by Cheese Rice

[IDO]

The GFS 12z ensembles have relative agreement up to about day 7:

http://cdn.nwstatic.co.uk/ensimages/ens.20121128/12/t850London.png

Showing the peaks and troughs of a zonal pattern. So although some are suggesting that FI starts in T48 the charts suggest good agreement for at least 7 days.

Scatter from there, but the op is no mild outlier here, to the contrary, following the mean. Solid pattern from the ensembles. Mean still about -2c so nothing mild about the zonality.

[Catacol]

What gives you that impression TEITS? I would really appreciate it if you could explain what makes you thing cold e,lys could occur. Thanks GSL

At this risk of treading on TEITS's toes, it is pretty obvious. We have a signal for high lat blocking and troughing over Europe, and the op runs are picking up on a series of systems zipping through on a NW to SE trajectory in the short to medium term. Possible/likely result is for one of these to end up over central Europe with the winds pulled into an easterly direction as heights rise to the north and north west. I would suggest that all the data is almost literally screaming for this to happen in the medium term - the fact that the EC32 hinted at it too, and GP posted yesterday in the same vein, is high quality back up context.

Edited November 28, 2012 by Catacol_Highlander

[bradymk]

Not a bad JMA tonight. Amplified again in its latter stages and i wonder where that low is going at t192. A colder run than GFS (not that the GFS is mild) and I still think around end of next week (7th or 8th) could be interesting for a time. Lets see what the ECM shows.

[liam300]

Sorry guys have we got any charts available to check the blocking? Heard mixed vibes in here last few days, of how its not as strong as expected etc...

[January Snowstorm]

Quite like the ECM this evening also.

Cold air surrounding us no matter where you look North, West and particularly East

It woudn't take much of an upgrade to be quickly back in the freezer

[Dunstable Snow]

Evening everyone,

Lets try to stay positive and not over react to each model run ( good or bad) and lets try and keep the big picture in focus. I remain very encouraged by the continuing disruption of the PV, troughing over Europe and the build up of cold in the key areas. We are about to the enter the start of winter and the overall prospects for this winter for cold and snow remain as good as I can remember.

To use a football analogy we are creating plenty of chances - sooner or later there is a great chance we will start scoring goals. This time last year we were penned deep in our own half without possession.

Cheers

[Isolated Frost]

504dm in nw scotland with some fierce polar maritime spells-

ECM very positive tonight, look at the 144 to see what this period looks like involving

[Nick F]

As I mentioned earlier this evening, watch the amplifying trough over eastern N America, this could be the precursor to amplification downstream later on next week/weekend following:

[Stuie]

After another year of thread watching I am going to take my annual plunge. There is not much mention of the jet stream and the part it plays or does not play.

From the start of December it is over the UK tracking from the NW

But then it takes a direct and pretty strong track from the west.

Does this just pull in warmer air from the Atlantic or is there much more to it than that?

Thanks,

Stu

[AutumnMists]

ECM doesn't provide a brilliant one ... but more of a sigh of relief in that it certainly doesn't catch up on ANY sort of milder than average conditions for it's whole lifetime. Hence, neither does it show deep cold obviously ...

Uncertainty continues .. all those saying it's over are just being stupid if you think about it.

Short term anyone?

[Captain Shortwave]

Hi, another newbie here, been reading the threads the past couple of weeks and of course the fact we are not buried in many feet of snow must deflate some people a bit. But things still looks good. Yes the Atlantic train seems to be gearing up, but with everything moving nw to se it would only take one of these to slide a little further south and then that will set off a chain reaction of increasing cold easterly or north east winds and high pressure building from the northerly quarter. There are a lot of good signs, we just need to wait for it to happen. Someone said a few posts back about that the onset will come at very short notice, that is probably a likely outcome in my opinion, we might get 24-48 hours warning but that's it.

[UV-RAY]

504dm in nw scotland with some fierce polar maritime spells-

ECM very positive tonight, look at the 144 to see what this period looks like involving

That chart would bring snow down to quite low levels from the Midlands Northwards.

[Nick F]

... and here comes the amplification mid-Atlantic:

[IDO]

As I mentioned earlier this evening, watch the amplifying trough over eastern N America, this could be the precursor to amplification downstream later on next week/weekend following:

GFS had that, but that low at 7.30 flattened the ridge in the Atlantic further in the run. A bit like the this weeks scenario. Repeat and wash?

Edited November 28, 2012 by i'm dreaming of...

[Alan Medlock Valley]

Not a bad JMA tonight. Amplified again in its latter stages and i wonder where that low is going at t192. A colder run than GFS (not that the GFS is mild) and I still think around end of next week (7th or 8th) could be interesting for a time. Lets see what the ECM shows.

People have been saying something along those lines for the past 2 weeks, I.E it's always over a week away in FI from something potentially good, last week a few models were showing a decent snow event for some of us on the 1st, not likely now is it?

OK nothing mild is showing but as of tonight (unless a monumental turn around happens) people need to stop grasping desperately at straws and admit that nothing noteworthy will arrive until at least the 2nd week of December.

Edited November 28, 2012 by Alan Medlock Valley

[Catacol]

Sorry guys have we got any charts available to check the blocking? Heard mixed vibes in here last few days, of how its not as strong as expected etc...

This will do you.

[Catacol]

... and here comes the amplification mid-Atlantic:

Yep - this could be the trigger. Could happen almost at any time next week or beyond - the models are struggling I think to get the speed of any transition right, and that system dropping into Europe with pressure rise behind it is the form horse I think from the transition from cold to colder as cold air is dragged westwards.

[Panayiotis]

... and here comes the amplification mid-Atlantic:

Am i right in saying this will bring snow to many in the midlands and possibly further south.. Edited November 28, 2012 by panayiotis

[shotski]

This will do you.

Hi Catacol, I haven't got the foggiest what that chart means or where the data is from ? Does it show some form of slider pulling in an easterly

or not maybe ? could you explain please, Thanx

Edited November 28, 2012 by shotski