Model Discussion - January 17th

[Cheshire Freeze]

That UKMO further outlook is a bit of a mystery.

The cold option suggests some form of northern blocking but its hard to imagine a scenario where both options are equally likely and its the first time I've seen the UKMO paint two such opposing pictures.

Generally if theres a strong signal to develop blocking its picked up across the ensemble suite, I wonder if this is a case of them thinking the blocking could end up in the wrong place.

Interesting ECM 144hrs chart, surely no more drama!

You know what Nick, I was just looking at that 144 hour chart and thought the very same thing. I think a lot more model drama coming up....especially in light of the ECM 32 day run which seemingly is suggesting Greenland blocking. I've never known a model watching time like this!

Edited January 17, 2012 by CreweCold

[LomondSnowstorm]

http://modeles.meteo...21-1-324.png?12

Doesn't look particularly 'zonal' at all in the long term. A huge spread in the ensembles too http://cdn.nwstatic.co.uk/ensimages/ens.20120117/12/t850Fife.png

You can see why the met office are uncertain - quite a large pack going for much colder uppers, with the rest scattered from just above the mean to above 0C.

The Kent ensembles are milder, reflecting that many of the colder runs are north/northeasterlies, but still there is a wide scatter with a cold cluster and milder clusters http://cdn.nwstatic.co.uk/ensimages/ens.20120117/12/t850Kent.png

[TEITS]

That UKMO further outlook is a bit of a mystery.

The cold option suggests some form of northern blocking but its hard to imagine a scenario where both options are equally likely and its the first time I've seen the UKMO paint two such opposing pictures.

Generally if theres a strong signal to develop blocking its picked up across the ensemble suite, I wonder if this is a case of them thinking the blocking could end up in the wrong place.

Interesting ECM 144hrs chart, surely no more drama!

Must admit I was rather surprised. Having said this though I did notice the 06Z GEFS ensembles suggesting blocking developing around Greenland in deep FI.

[nick sussex]

The ECM seems to be developing an amplified upstream pattern in the USA and note the angle of the low pressure in towards the UK.

The 192hrs may well cause a stir if we see some trough disruption.

[Brum Watcher]

Intersting ECM out to 168. -4 uppers widely out west and east and a different question being asked i suppose.

[BLAST FROM THE PAST]

That UKMO further outlook is a bit of a mystery.

The cold option suggests some form of northern blocking but its hard to imagine a scenario where both options are equally likely and its the first time I've seen the UKMO paint two such opposing pictures.

Generally if theres a strong signal to develop blocking its picked up across the ensemble suite, I wonder if this is a case of them thinking the blocking could end up in the wrong place.

Interesting ECM 144hrs chart, surely no more drama!

Unfortunately YES Nick, 168 continues earlier run, its on meteociel and the angle is not as good as wetter or NW so can't see the upstream. Just looked at 168 on wetter and there is another LP/SW coming off the esatern seaboard/ Newfoundland, I reckon that will prevent a link up to Greenland.

Oh no just seen t192

BFTP

Edited January 17, 2012 by BLAST FROM THE PAST

[Tim Bland]

Intersting ECM out to 168. -4 uppers widely out west and east and a different question being asked i suppose.

Looks like cold zonal affair to me. Snow on higher ground and Scotland transient further south

[The Northern Ramper]

It would be nice if people posted pics of discussed charts.

[nick sussex]

Unfortunately YES Nick, 168 continues earlier run, its on meteociel and the angle is not as good as wetter or NW so can't see the upstream. Just looked at 168 on wetter and there is another LP/SW coming off the esatern seaboard, I reckon that will prevent a link up to Greenland

BFTP

The 192hrs is a real let down, that pesky shortwave near Newfoundland stops the Azores high retrogressing.

It certainly showed promise upto 168hrs.

[stratty]

NIce elongation of PV and then obliteration though over north Canada

[BLAST FROM THE PAST]

The 192hrs is a real let down, that pesky shortwave near Newfoundland stops the Azores high retrogressing.

It certainly showed promise upto 168hrs.

Yes Nick it did, and I have to say the propensity for SW after SW to be relentlessly modelled is a real concern, we know there is no guarantee of cold in the UK BUT even so, this is just a concern now.

FWIW there is a signal for a more 'lively/stormy' period come 25th -27th but currently there is no block backing west for it to favourably interact with for cold option. Solutions showing deep LP near UK at this timescale is near the mark IMO...but where will it be positioned and I hoped we'd have colder block/pool of air nearer our shores by then.

BFTP

Edited January 17, 2012 by BLAST FROM THE PAST

[phil nw.]

I know it`s tempting to use the Met O. outlooks to support a possible change to cold but they are not for this thread.

We have had to delete some posts of this nature already.

Please confine your discussions to the usual model output.

I am sure most of you are aware there are other threads to discuss the Met outlook.

Thankyou all.

[nick sussex]

The ECM 144hrs is my chart of the day!

Which of course isn't difficult given the rest of the output!

If you look at the base of the low to the west of the UK its trying to develop a shortwave as the higher pressure to the ne is trying to force it to disrupt.

Look out for the ECM ensembles tonight at that timeframe do any shear some energy off and take this se'wards at 168hrs.

[Cumulonimbus Tower]

The end of the ECM seems to show the PV lifting right out of Greenland and Baffin. This could be a great signal further down the line...... if the ECM at 216 could be believed

[Matty M]

A good ECM T120hr chart to build on

Lets have some PMA peoples and we could do this!

Not far off

[chionomaniac]

Whereas the picture over the UK could be misconstrued as a continuation of zonality this is very much a small section of a far bigger picture. The ECM run tonight suggests something which was discussed a couple of days ago. The large polar vortex which has shown no signs of leaving the Canadian segment gets stretched in two until it snaps in half. Great for HLB's to form.

Edited January 17, 2012 by chionomaniac

[Cloud 10]

Interesting run from the ECM with a big -ve AO signal.

Polar Vortex taking a real pasting.

[ForeverPomeroysnow]

What is a HLB?

[phil nw.]

What is a HLB?

High Latitude blocking-look for yellows at 500hPa over the Polar region.

[nick sussex]

Whereas the picture over the UK could be misconstrued as a continuation of zonality this is very much a small section of a far bigger picture. The ECM run tonight suggests something which was discussed a couple of days ago. The large polar vortex which has shown no signs of leaving the Canadian segment gets stretched in two until it snaps in half. Great for HLB's to form.

As long as we don't end up with a western based negative NAO!

Thats what you could read into the UKMO uncertainty.

Did you read the NOAA update earlier they talked about one PV segment heading to Alaska and the other heading to Baffin.

[Gibby]

Pretty uninteresting operationals tonight with the general pattern of Low pressure to the North and Northwest coupled with High pressure to the South or Southwest maintained throughout. The resulting weather implied sees spells of cool to cold zonality with rain and showers, wintry on Northern hills at times with the driest and mildest conditions towards the SW. The GFS ensembles show pretty much uniformity on sustained normality in temperatures for London for this time in January. It will be interesting to see what the end of the ECM ensembles show later in respect to the Mets update today.

[chionomaniac]

As long as we don't end up with a western based negative NAO!

Thats what you could read into the UKMO uncertainty.

Did you read the NOAA update earlier they talked about one PV segment heading to Alaska and the other heading to Baffin.

Yes Nick.

I have to say the one thing troubling me is a scenario like February 2009 developing but without the initial easterly. The background signals are not too dissimilar.

[Matty M]

Whereas the picture over the UK could be misconstrued as a continuation of zonality this is very much a small section of a far bigger picture. The ECM run tonight suggests something which was discussed a couple of days ago. The large polar vortex which has shown no signs of leaving the Canadian segment gets stretched in two until it snaps in half. Great for HLB's to form.

Yea Chio i think the models are getting geared up for a really cold February, and things may kick off in 7-10days from now. I think there are plenty of signs to be positive particularly with the ECM 32 dayer being very positive for Greenland height rises and colder conditions

[bluearmy]

i havent paid too much attention to the threads today but the gem 00z and the bom 12z both develop good patterns post T200 with the atlantic energy headed se and blocking forming to the north. the ecm NH charts look interesting on both the 00z and 12z runs for the period following the runs as heights build over the arctic uptream and the jet appears to run out of steam. i can see where we might be headed but the latest parallel ens, depite being amplified only manage to build two or three decent fi solution as far as cold for nw europe is concerned.

[BLAST FROM THE PAST]

Whereas the picture over the UK could be misconstrued as a continuation of zonality this is very much a small section of a far bigger picture. The ECM run tonight suggests something which was discussed a couple of days ago. The large polar vortex which has shown no signs of leaving the Canadian segment gets stretched in two until it snaps in half. Great for HLB's to form.

Indeed C but also as discussed in past somewhere has to be in the wrong place.....it could well be us but it seems clear now that any 'real' effect change is 10+ days away, with the hemispheric change already in motion.

BFTP

Edited January 17, 2012 by BLAST FROM THE PAST