Model Output Discussion 4th Dec.2013-12z onwards.

[nick sussex]

   TTbh Nick, the strong jet could work for us IF we can force some blocking to our NE that is able to push west. the high heights to our south do look like they are prepared to retrogress back into the atlantic so we could force a euro trough if the jet can be deflected south. i suspect that the only block able to do that to this jet would be a retrograding siberian block but we arent seeing that currently modelled.one thing to watch over the next few days are these little pockets of higher heights that are pushed into the polar region and then cut off. historically, they can lead to all sorts of fun within a week or so. on the flip side, they can just get mixed out quite quickly.

Yes in terms of the strat you mentioned in your earlier post, those weakening zonal winds have shown up for quite a few days, maybe this can be the curveball thrown into proceedings!

 

For newbies what BA was talking about was this here, you can see there the zonal winds towards the pole are weakening as shown by the blueish colours:

 

Edited December 13, 2013 by nick sussex

[Stuie]

Worth keeping an eye on how this low pressure system develops, yet another mini uk storm from the west.

 

Edited December 13, 2013 by StuieW

[Mokidugway]

Black hole incoming on the GEM @240hrs! I wonder what conditions will be like if we were in the centre? 

strong north west winds with scattered singularities !!...

[NorthernRab]

All hail the mighty vortex!

 

Certainly no sign of any northern blocking in our neck of the woods throughout the entire 12z run.

 

It's actually so mighty in this case that it could deliver a lot of snow!

 

Careful what you wish for Purga 

Edited December 13, 2013 by NorthernRab

[Barry12]

Yes the op is ordinary but the control has potential, dragging the jet south via a trigger low off the PV trough:

 

To be honest nearly every member at T384 is different to the others so we are entering a very volatile period, so there is possible reason to believe we might start seeing real cold snowy charts, though no sign yet.

 

You are analyzing charts that are more than 2 weeks away, which is rather pointless due to the fact they'll look completely different on the next run. Of course every member will look differently at more than 384 hours out. Due to the Chaos theory, small changes at early time frames will make them look completely different by the time there at that range.

[Panayiotis]

PV difference between ECM and GFS @168hrs. The ECM is considerably better with some sort of heights to the NE of Greenland! Are we going to see the black hole @240hrs?

Edited December 13, 2013 by Panayiotis

[shedhead]

For the 4th or 5th GFS run in a row now the Op has been one of the coldest members in FI and actually the coldest member right on Xmas....yet again highlighting the folly of looking at T+288hr charts and discussing the marginalities of snow. Always worth checking the emsembles before getting to exited. There is of course a chance that the UK will be in Pm air at T+288hrs, but it's a slim one, with the chances of that chart verifying being even slimmer.

 

Edited December 13, 2013 by shedhead

[nick sussex]

PV difference between ECM and GFS @168hrs. The ECM is considerably better with some sort of heights to the NE of Greenland!

The UKMO would beat both of those at T168hrs, with the UKMO as the two lows phase you'd at least get some energy disrupting se not just this all going ne. I certainly hope that the UKMO pulls this one out of the bag!

[Summer Sun]

Remaining very unsettled at t192 with the potential for severe gales in the north at times

 

[Panayiotis]

BOM following the GEM with the black hole @240hrs!

[Purga]

Despite Blue Army's optimism about where the UKMO was leading us ECM brings things back down to earth with a zonal bump

 

I really can't see anything decent developing here

[Summer Sun]

t216 see's things remaining unsettled though not as windy as previous days though its turning cooler

 

Edited December 13, 2013 by Summer Sun

[Captain Shortwave]

BOM following the GEM with the black hole @240hrs!

ECM is going to go the same way too if the T216 chart is anything to go by

[Panayiotis]

The UKMO would beat both of those at T168hrs, with the UKMO as the two lows phase you'd at least get some energy disrupting se not just this all going ne. I certainly hope that the UKMO pulls this one out of the bag!

Yes it certainly seems better and hopefully it has called it right. The ECM sends some heights towards the pole (view original post) but with the UKMO I would expect those heights to be in a similar position but more significant which should shift the PFJ further south, something similar happens on the 12z JMA, its something we should be looking for....

Edited December 13, 2013 by Panayiotis

[Purga]

charts are still total crap, the models are trying to get rid of the euro high in FI but i bet it hangs on with most of the rain reserved for the north and west and it will just stay dull mild and dry here

 

i have the windows open here

Don't jump! Its only the weather and it will get colder - eventually. LOL

[Summer Sun]

The latest NAO update remains positive today with hints of it heading down wards as we move to January

 

[Barry12]

Don't jump! Its only the weather and it will get colder - eventually. LOL

 

Nothing mild on the ECM

 

[EML Network]

Common give me a break :-(

 

Absolute knightmare of a ECM at 216 High pressure stretching from China to our East, right the way to the Eastern Seaboard of the States to our West.

 

Might as well give up and go home tbh

 

[Summer Sun]

ECM at t240 sees the euro high extending up to parts of the south, so wettest and windiest in the north west driest in the SE but cooler for all

 

 

A closer view

 

Edited December 13, 2013 by Summer Sun

[nick sussex]

I'll be interested to see what the UKMO do with tonights fax charts because even at T120hrs there are some differences between it and the ECM, GFS.

 

If you follow it in terms of the pattern to the ne, theres also a difference with that piece of the PV, the ECM/GFS want to take this back nw between 120 and 144hrs the UKMO takes this piece se.

 

Given the tilt of the troughing of the UKMO versus the misery combo ECM/GFS and the differences to the ne its simply impossible for the UKMO to develop the same, some energy will have to disrupt at least east or se, I'd take a look at the JMA as to what the probable worst case scenario would be at 168hrs.Bearing in mind that the UKMO is much better than that at T144hrs to the ne,so you'd have to factor in a bit more disruption and the pattern further south.

 

Interesting little sub plot this evening, if the UKMO is right that won't suddenly deliver sledge weather but it might at least bring things further south with a bit more energy heading into central Europe.

 

If you look at the GEFS theres not a single member that backs the UKMO at T144hrs, that's very unusual you'd expect one ensemble to pick the same solution. It's  a shame that the stinges at ECM pulled the postage stamps as we could have seen if there was any support there for the UKMO operational run.

Edited December 13, 2013 by nick sussex

[Captain Shortwave]

In realistic terms if we want a white Christmas we really need the UKMO to be right as that would bring the cold air in the Arctic a lot closer to the UK and would at least give us a chance. If the others are correct, sure we might get a PM shot during the festive period but we would be looking at very slim odds. 

No pressure UKMO, can you reproduce or even better this afternoons runs tomorrow.

[tinybill]

this  something the coldies  will  love  a white  xmas  day!!!

[Richie V]

Post of the month! Common sense prevails. BRING THEM GALES!

Common give me a break :-(

 

Absolute knightmare of a ECM at 216 High pressure stretching from China to our East, right the way to the Eastern Seaboard of the States to our West.

 

Might as well give up and go home tbh

 

[nick sussex]

In realistic terms if we want a white Christmas we really need the UKMO to be right as that would bring the cold air in the Arctic a lot closer to the UK and would at least give us a chance. If the others are correct, sure we might get a PM shot during the festive period but we would be looking at very slim odds. 

No pressure UKMO, can you reproduce or even better this afternoons runs tomorrow.

My head says the UKMO is a rogue operational run that will bite the dust by tomorrow, my heart says its nearing Xmas and that slowing of the zonal winds in the strat near the pole will deliver an emergency pressure rise up there to deflect the jet further south and that the UKMO still believes in Santa!

Edited December 13, 2013 by nick sussex

[Frosty.]

The GEFS 12z mean shows a rather chilly and very unsettled outlook with frequent gales and potentially stormy conditions, especially towards the northwest of the uk, spells of heavy rain alternating with squally showers and cold enough in the north of the uk for the ppn to turn wintry at times with snow in places, the cold air occasionally digging southeast into the southern half of the uk with a risk of hill snow from time to time, especially later in the run between xmas and new year. I think there could be a more pronounced spell of wintry weather embedded into the generally very disturbed upcoming pattern. As for this weekend, a double whammy of stormy weather for the north and west of the uk, especially for the western half of scotland with severe gales and torrential rain, then after a brief lull on sunday morning, an even more severe spell with storm force s'ly winds and more torrential rain followed by squally wintry showers as winds veer to a progressively colder and very strong westerly flow, lots more of the same through next week onwards.