Model Output Discussion - 8th December Onwards

[suxer]

Agree on this, although the question is also how much milder, and how far north in my mind. And again all this tallies with the ec32 modelling of late.

could you expand on this ec 32 idea in more detail?

[TEITS]

I have to say I'm shocked, looking at the earlier part of the run it looked like the Atlantic was at a very unfavourable angle and then somehow manages to develop hints of an undercut.

Still that shortwave is deep and looks dreadful in terms of wind and rain, hopefully this is the GFS overblowing things.

Worth also mentioning that based on the past sometimes an E,ly does not always arrive on the first attempt when you have a block to the E. I do recall a few occasions when I experienced a spell of frosts followed by a brief milder spell before the snowy E,lys arrive.

Very impressive how a deep low of 955mb is sent packing by none other than the GFS.

Im going to say it now this isn't game over. The milder spell could yet prove only brief.

[Nick L]

The GFS is notorious for blowing up lows to crazy proportions, I wouldn't take it too seriously just yet, especially as it has appeared seemingly from nowhere.

Although the fact it's trying to slide under the block rather than ploughing straight through it is a positive. But going by this it's gone from blizzards disrupting my flight to a monster Atlantic storm - I just want a nice boring day on Sunday please :lol:

[Wayneywoo]

I think we can all see just how much the models are struggling at the moment. I'm not downbeat at all about the situation we are about to enter. I am still encouraged as I see FI at around T72 which seems to be when the PV starts it's migration to Siberia.

I have to say I am feeling a little sick, this rollercoaster has to be the longest I have ever been on!

[in the vale]

That low just doesn't look 'natural' to me, don't ask me why, but to me a good indication that the atlantic incursion just isn't modelled anywhere near right, both in terms of angle and speed. My (limited) experience suggests that the latter part of next week is nowhere near understood from any of the big models.

[Gavin Hannah]

Worth also mentioning that based on the past sometimes an E,ly does not always arrive on the first attempt when you have a block to the E. I do recall a few occasions when I experienced a spell of frosts followed by a brief milder spell before the snowy E,lys arrive.

Very impressive how a deep low of 955mb is sent packing by none other than the GFS.

Im going to say it now this isn't game over. The milder spell could yet prove only brief.

It is a colder output for sure. Mostly under to 0 line. The high ground could get a snowy pasting.

[damianslaw]

GFS often overblows low pressure systems - but there could be some mileage in the 18z outputs, the projected build of heights to the east looks very strong indeed and we are going to see a significant squeeze in isobars over and near the country - low pressure systems tend to be at there deepest now, and we are in possible 'secondary' low territory later next week as well..

As I said in my last post - I expect the trough to drop SE as it has done for so long with jet angled more on NW-SE axis in the run up to christmas, undercutting very much a plausible outcome - and probably the eventual outcome as heights rise to the NW coupled with the russian heights holding strong and not sinking.

[Cheshire Freeze]

Well the trend of the day seems to be continued on the GFS 18z. That high seems to want to put up a real fight...

Before this it looks quite disturbed with the potential for some concerning rainfall.

[nick sussex]

120hrs fax chart, chance of snow especially for northern areas as UKMO haven't pushed the milder air ahead of the precip.

[snowy weather]

What's and undercut?????

[snow1975]

How's about a Northerly reload in time for Xmas?

[cyclonic happiness]

Oh look! the easterly's back! and without looking I bet the high starts to drift over to Greenland later on??? amirite? amirite?

[Weathizard]

Anyone noticed a general westward trend in the last few runs? Hmmm, a part of my mind thinks this isn't over by a long shot as I've been saying in my previous posts

[Nick L]

GFS often overblows low pressure systems - but there could be some mileage in the 18z outputs, the projected build of heights to the east looks very strong indeed and we are going to see a significant squeeze in isobars over and near the country - low pressure systems tend to be at there deepest now, and we are in possible 'secondary' low territory later next week as well..

As I said in my last post - I expect the trough to drop SE as it has done for so long with jet angled more on NW-SE axis in the run up to christmas, undercutting very much a plausible outcome - and probably the eventual outcome as heights rise to the NW coupled with the russian heights holding strong and not sinking.

Absolutely. It's unusual to see the GFS thinking that the block will hold out so well. Numerous times in the past we've seen it blow the block away with ease. Although the last thing the UK needs is for the block to keep lows at bay over us! Let's see what sense the ensembles can bring.

And after this week's debacle I wouldn't trust an easterly being shown until T72 at the earliest!!

Edited December 8, 2012 by Nick L

[weatherguy]

I'm not suggesting this is a realistic chart in terms of exact synoptics, but isn't this sort of set up what GP suggested before? (wrt heights building near Greenland, and the PV moving east)

And no, I refuse to get sucked in to talking about another easterly (yet)!

Edited December 8, 2012 by weatherguy

[BLAST FROM THE PAST]

Oh No....Look familiar???? Expect another shortwave as we get to t96

BFTP

[Cheshire Freeze]

I'm not suggesting this is a realistic chart in terms of exact synoptics, but isn't this sort of set up what GP suggested before? (wrt heights building near Greenland, and the PV moving east)

Yes, I believe the vortex movemment has caused and is causing the NWP all sorts of issues.

[Gavin Hannah]

I hate to say it, but I think we are going to have to endure a couple of weeks of failed attempts of Easterly becoming established. I do think it's going to be more cold than mild on average and with the mobile outlook, very wet, and perhaps snowy on the high ground. All we need is one of these lows to undercut and it's game on.

I prefer the 18Z run with a cooler outlook which will give us some snow events.

[bobbydog]

Anyone noticed a general westward trend in the last few runs? Hmmm, a part of my mind thinks this isn't over by a long shot as I've been saying in my previous posts

as have i and tried to point out why but no-one seems to have noticed!!

[Baynesey (snow chaser)]

Been a lurker pretty much since 2005 but i have learnt a few things.

ive noticed over the last few years the GFS always throws outragously deep lows at us from the west, only for them to be downgraded majorly as they get closer to T0.

if this was the case again would the low undercut the high easier??

[Paul]

could you expand on this ec 32 idea in more detail?

Did that a little earlier

What we're seeing in the mid-range models at the moment is pretty much the theme which has been recurring on the EC32 for a few weeks now - a pretty cold start to December, occasionally less cold blips (such as this weekend), and a more sustained milder/less cold spell into mid month(ish) - albeit with colder air continuing to flirt with the northern half of the country.

Up to Thursday's update the EC32 was bullish in bringing much colder air back in time for Xmas, Thursday saw that wane a bit but the general theme is still there or thereabouts. Next update Tuesday will be a really interesting one - it's only one model of course and is certainly not infallible but it's doing pretty well so far this month...

[nick sussex]

Latest NAE suggests the chance of some snow showers into the ne late Monday possibly into East Anglia and also east Kent later, the flows quite slack so unlikely to make much progress inland.

In terms of the GFS we can only hope thats its overdoing that shortwave as really that looks bad news in terms of rain and wind.

In terms of the overall pattern all the models agree on the Atlantic making progress, but really how far east is uncertain and also what impact high pressure will have to the east.

[Gavin Hannah]

Just thought I would throw Joe Bastadi's opinion into the mix regarding the ECM Monthlies.

Joe laminate floori â€@BigJoelaminate floori

Just got a look at the new ECMWF monthlies. If true, this will be the coldest winter in Europe overall since at least the 1980s.

Edited December 8, 2012 by IBringTheHammer

[J10]

Absolutely. It's unusual to see the GFS thinking that the block will hold out so well. Numerous times in the past we've seen it blow the block away with ease. Although the last thing the UK needs is for the block to keep lows at bay over us! Let's see what sense the ensembles can bring.

And after this week's debacle I wouldn't trust an easterly being shown until T72 at the earliest!!

I wouldn't trust it at T+0.

Seriously though the low pressures are really struggling to get that far past the meridian, things could get interesting from here, if not more than a little wet.

Edited December 8, 2012 by Jackone

[Pixel]

What's and undercut?????

a word of advice from someone who has asked such questions... don't ask such questions in the model thread till the model run is finished. Wait till it's quiet and some one nice will tell you.. I'd love to tell you what an undercut is but alas I do not know.