639 replies to this topic

[mountain shadow]

KTtom, on 26 December 2011 - 08:05 , said:

ECM +240 seems to be the chart of the morning again at day 10 as it has been for the last couple of days, trouble is, its not getting any closer! I'm not the most patient of guys but by the time the Stratosphere gets itself sorted out we should be in for some impressive blocking come April!

This is exactly what I was alluding to yesterday. An arctic high offers far more prospects then a raging PV over the pole. Does anyone know what the furthest poleward ensembles location we can get?

Now we need to see GFS show a bit of support.

[TomSE20]

Morning all,

Yes, quite a lot of difference this morning amongst the models, out in FI.

http://www.wetterzen...cs/Recm2401.gif

Our resident high has pulled west out into the Atlantic, with the jet tilting more NW/SE and some interesting developments in the far NE of that chart.

http://www.wetterzen...s/Rtavn2401.png

GFS having none of it and maintaining a stubborn high pressure cell over France.

Right off to work, how I hate Boxing Day! Kauto Star for the King George, come on old fella. What is that man rambling on about!

Regards,
Tom.

[nick sussex]

Morning all

Hope you all had a good Xmas. Santa has delivered us the best chart of the winter from the ECM at 240hrs, the GEM is looking okay at the same time frame and even the wayward BOM shows some promise!

The GFS is like the gatecrasher at the party who isn't welcome, that for the timebeing doesn't want to know and keeps its PV love-in over Greenland. Could the ECM be too progressive with its change, thats still a possibility.

We'll just have to wait and see over the coming days.

[bluearmy]

Given that the ECM op at t240is the warmest of the 51 run suite, i doubt the pattern over the arctic is correctly modelled.

[s4lancia]

ECM digs us out of the 00z mire with a very interesing last couple of FI charts.
The state of the Northern Hemisphere in 24 hours time...


Then how the ECM sees it in 10 days...



It certainly sees things breaking up quicker than is likely IMO but it's the most promising chart of the winter in terms of potential down the line.

Surely we are going to see the AO start to take a downwards hike in the next few days. This is its forecast presently going into Jan, watch this trend Neutral then negative in days to come I suspect...


I posted a few weeks back I could see an Arctic high forming and that we at least had a chance (albeit a real outside chance) of it effecting us later on down the line. I know some are continually pointing out that Strat warming and its effects on our weather is no direct path to UK cold and I couldn't agree more. But... that's in the details further down the line. Before we can even consider getting there this monster vortex has to be weakened and like it or not what we have setting up for January is going to makes some in-roads into doing just that. Think of it as the big enemy at the end of the level on a video game. You don't come waltzing in with your pistol take a shot and down he drops! You load up with ammo, bring the heftiest weapons and pelt him till, eventually, he topples over and the job is done! Sometimes a few plum shots and he goes down quick, other times a continual barrage seems to have little or no effect and after what seems like an age you're out of ammo and you lose!

Edited by reef, 26 December 2011 - 11:55 .
Model thread, not Ian Brown thread

[nick sussex]

bluearmy, on 26 December 2011 - 09:25 , said:

Given that the ECM op at t240is the warmest of the 51 run suite, i doubt the pattern over the arctic is correctly modelled.

Maybe the others have the jet further south? The operational run drives a sw flow into Holland on days 9 and 10, if the troughing is further south and east that might explain the others.

If you look at the ECM ensemble maps at 168hrs quite a few reduce the influence of the Azores high and also some bring higher pressure at a more favourable angle into northern Scandi.

http://www.ecmwf.int...t!2009112700!!/

Edited by nick sussex, 26 December 2011 - 09:59 .

[bluearmy]

nick sussex, on 26 December 2011 - 09:58 , said:

Maybe the others have the jet further south? The operational run drives a sw flow into Holland on days 9 and 10, if the troughing is further south and east that might explain the others.

If you look at the ECM ensemble maps at 168hrs quite a few reduce the influence of the Azores high and also some bring higher pressure at a more favourable angle into northern Scandi.

http://www.ecmwf.int...t!2009112700!!/

The mean looked ok with ridges east of svaalbard and west of Alaska trying to split the vortex in a similar way to the op. Guess I was just trying to put a brake on things a tad, especially with naefs not really interested.

[nick sussex]

bluearmy, on 26 December 2011 - 10:03 , said:

I can understand why, otherwise we could get a runaway hope train! If we see those pressure rises within 168hrs then I'd be happy to hop on board!

We can just hope that this initial strat warming might do the trick and then we don't have to wait for another one to finally send that PV packing from Greenland.

[nick sussex]

The GFS 06hrs run continues with a similar trend to its earlier 00hrs run especially in its lower resolution output. Although it did have a similar pattern to the ECM before the drop down into that lower resolution.

I think the key is whether the ECM can deliver those pressure rises over the Arctic into the 168hrs timeframe or whether they keep remaining stuck at the 216-240hrs like the pot of gold at the end of the rainbow.

Edited by nick sussex, 26 December 2011 - 10:51 .

[ITSY]

GFS not yet on board with ECM - which I reckon is overplaying the downgrade of the PV in any case. Certainly change looks like it's nearing the horiZon, but to what remains uncertain until GFS and ECM sit in the same ball park

[OldMetMan]

Hope everyone had a good Christmas.

I've picked up a couple of things from today's runs. First, the GFS is taking the jet further S after Wednesday's intense LP, with pressure much lower across the UK. Beyond that, the model reverts to the familiar SW zonal flow but with LP running further S before then, it brings the possibility of cold air breaking through.

The other thing I noticed was HP once again being forecast to start building over W Russia by the GFS. That, combined with the more southerly jet, again suggests a possibility of colder air breaking through.

Still no sign yet of any major long wave amplification.

[Barb-]

Surprised there's little talk of the nasty storm for Wednesday, could be some severe conditions in N. Ireland, Scotland and N. England,




Then it looks like an spell of wet, windy, disturbed weather for most. Then some promising signs into FI for the cold and snow lovers, long way to go yet though.

Edited by Barb-, 26 December 2011 - 11:06 .

[i'm dreaming of...]

Latest GFS has sent any hope of prolonged cold packing, no sign of any blocking; in fact it strengthens the Atlantic, sending wave after wave of zonal. Transitional cold for the North but continuing with overall mild to the south. I think if this is the situation on the 11th then we can confirm a Bartlett, and taking the setup then, there is little relief for a change for probably another 7-10 days going forward. ECM seem to have members who believe a change will happen and they keep this at the end of their runs, whilst GFS are more cautious, keeping the default pattern. I think both are correct; the change is on the menu but neither are sure when, with ECM simply more pro-active in its modelling whilst GFS will jump on the bandwagon, if & when the synoptics are more persuasive.

"If you add a little to a little, and then do it again, soon that little shall be much."

[Tellow]

Oh yeah shouldn't a new thread of the model output be starting today?

[Frosty039]

Another shocker of a gfs 06z run for the south at least with very few cool incursions and the limpet high to the south of the british isles is not planning on going anywhere, lows continue to pile in from the atlantic at regular intervals bringing very brief cold incursions into the far north of the uk but very little in the way of snow to low levels, it also looks too windy for frost for much of the time although the southeast would have lighter winds at times being closest to the high with a few frosty nights and some fog but the north and west look very unsettled throughout.

[shedhead]

i, on 26 December 2011 - 11:26 , said:

Latest GFS has sent any hope of prolonged cold packing, no sign of any blocking; in fact it strengthens the Atlantic, sending wave after wave of zonal. Transitional cold for the North but continuing with overall mild to the south. I think if this is the situation on the 11th then we can confirm a Bartlett, and taking the setup then, there is little relief for a change for probably another 7-10 days going forward. ECM seem to have members who believe a change will happen and they keep this at the end of their runs, whilst GFS are more cautious, keeping the default pattern. I think both are correct; the change is on the menu but neither are sure when, with ECM simply more pro-active in its modelling whilst GFS will jump on the bandwagon, if & when the synoptics are more persuasive.

"If you add a little to a little, and then do it again, soon that little shall be much."

Prolonged cold?? I'd say the 06z has sent the prospect of any cold packing, with a 16 day run that can only be described overall as average to mild for the north and mild across the south. ECM as others have suggested looks a far better prospect later in the run, but I've never taken a T+240hr chart as read and I'm not about to start doing so now. Hopefully the result of the strat warming is starting to be picked up, but a few more similar runs are required from ECM before I get too exited, as well as some backup from GFS.

Certainly been fairly mild of late, well that's one way to describe it, albeit wrongly....

Edited by shedhead, 26 December 2011 - 11:51 .

[snowingman]

... Could this be the MILDEST mid winter spell ever?? currently averaging 9C above normal for the past 36 hours ! based on the charts - this should continue for the next 2 weeks..... The grass will be needing cut on New years day at this rate - any cold is way way up North!! some one somewhere in the NH must be experience winter - but NOT the UK!

[Great Plum]

The 06 GFS was a mild outlier in FI... Don't panic!

http://www.netweathe...;type=ens;sess=

[January Snowstorm]

Worth noting that the current conditions are exactly to plan as per GP's forecast.
Mid Jan at the earliest is what he said and for now i'm happy with that.

If you are around GP a little update as to whether we are still on track would help us coldies!

[reef]

New thread:

http://forum.netweat...er-1st-january/