Model Output Discussion 26/11/2012 18Z onwards

[snowmadchrisuk]

I find it amazing how just a motorway can be the boundary on so many occassions to rain ro snow. It literally is that one side can be rain and the other snow.

I`m in Frome and the local weather variables are probably some of the most localised on the planet. Micro climate between Frome, Westbury, Sheppton Mallet ,Trowbridge Bath, huge weather variations can happen here and anyone on this thread who lives nearby knows what i`m on about. the charts might just bring some more of this soon.

here`s hoping for further improvement in them.

It can be a blessing or a nightmare living in the SW . Often we are to close to the warm sector and miss out on Snow , but on the other hand when a prolonged Cold spell set's in we can get more than anybody else as fronts try and push in from the Atlantic , the Cold air to the East Wins and the Heavy Snow stalls over our area and we can end up with 3 or 4 times the Snow depths of places East of the Country . I feel the latter option may be valid this Winter as I can see a big Cold spell setting up as we head into December. (second week my hunch)

Edited November 27, 2012 by snowmadchrisuk

[Frosty.]

I find it amazing how just a motorway can be the boundary on so many occassions to rain ro snow. It literally is that one side can be rain and the other snow.

Yes thats true, north of the M4 it's snow, south of it is heavy rain, so strange. It looks like becoming more interesting over the weekend with low pressure and cold air over the uk, a fairly potent mix and rain/sleet/snow on the agenda, colder and drier further north and east but wintry showers to N/E coasts with frosty nights.

[Kentish Snowman in Yorks]

Mystified by the childish UKMO bashing. This is science, not football. They're fairly happy with how the GM sits now:

" 3. Modifications: The GM’s ideas of a slack and cold northerly over the UK during the weekend is supported by other models. The next Atlantic system pushes in during Monday and this will have a snow risk ahead of it. The GM was accepted without modification"

I am a little bemused by this as well. I'm not sure how to post yesterday's charts but looking at today's 120 UKMO chart, from memory, it is not too different from yesterday's UKMO 144?

Ok, so the evolution going forward might not what most might be after in terms of deep cold and snow, but this is a constantly evolving situation, and I can see absolutely nothing in the models that suggests that mild southwesterlies are about to become entrenched over the UK.

Indeed, if anything, ECM / GFS et al have been slowly moving towards the UKMO evolution if anything, and I would not be surprised if there are one or two 'white' surprises that pop up in the models at short notice on the next few runs. Time will tell...

[The Eagle]

The charts are very good and cold to 120hrs. The main thing to look for is to see how much resistance is put up on the cold side to the incroaching Atlantic fronts this weekend and whether we could get sliding LP's bringing frontal snow risk and maintaining the cold air flow in to the longer term. I don't think this is at all certain that milder weather will break through later in the weekend.

[Radiating Dendrite]

The charts are looking cold and below average - I think some may have been expecting too much.

You are only going to get prolonged ice days ( a la 2010) in extreme circumstances in the UK. The Northern blocking is good and there are some decent sliders being modeled.

Below average and possibly snowy still looks the form horse!

[Rob K]

I am a little bemused by this as well. I'm not sure how to post yesterday's charts but looking at today's 120 UKMO chart, from memory, it is not too different from yesterday's UKMO 144?

Ok, so the evolution going forward might not what most might be after in terms of deep cold and snow, but this is a constantly evolving situation, and I can see absolutely nothing in the models that suggests that mild southwesterlies are about to become entrenched over the UK.

Indeed, if anything, ECM / GFS et al have been slowly moving towards the UKMO evolution if anything, and I would not be surprised if there are one or two 'white' surprises that pop up in the models at short notice on the next few runs. Time will tell...

I fully agree. UKMO model has outperformed all others over the last few days. It has never wavered regarding this weekend while GFS and ECM have been all over the place.

All we are seeing now is the slight breakdown coming into the 144hr range if UKMO. It certainly hasn't "backed down" at all.

[Absolute Zero]

The charts are looking cold and below average - I think some may have been expecting too much.

You are only going to get prolonged ice days ( a la 2010) in extreme circumstances in the UK. The Northern blocking is good and there are some decent sliders being modeled.

Below average and possibly snowy still looks the form horse!

Not forgetting 2009

[Turnedoutniceagain]

I find it amazing how just a motorway can be the boundary on so many occassions to rain ro snow. It literally is that one side can be rain and the other snow.

I`m in Frome and the local weather variables are probably some of the most localised on the planet. Micro climate between Frome, Westbury, Sheppton Mallet ,Trowbridge Bath, huge weather variations can happen here and anyone on this thread who lives nearby knows what i`m on about. the charts might just bring some more of this soon.

here`s hoping for further improvement in them.

True - the M4's a well known barrier between bliss and misery !!

[ukpaul]

I fully agree. UKMO model has outperformed all others over the last few days. It has never wavered regarding this weekend while GFS and ECM have been all over the place.

All we are seeing now is the slight breakdown coming into the 144hr range if UKMO. It certainly hasn't "backed down" at all.

The UKMO has been very impressive, okay it doesn't go beyond 144 but when it has got into that time period it has never wavered. That, with a setup which other models have found difficult to pin down. There is still a definite possibilty that things may be pushed west however so I wouldn't like to say that they've been exactly right before the actual event. As for a potential slider after that, the margin for error is huge so I would expect to see that come down to 48 hours if it does, indeed, transpire.

In the mid range I have to admit that neither GFS or ECM have impressed.

[summer blizzard]

GFS6z was great, not only do we get a snow event next Monday but then we get a brilliant FI...

[Turnedoutniceagain]

GFS6z was great, not only do we get a snow event next Monday but then we get a brilliant FI...

Mmmmm - 528 damline right through the middle.....

[Tim Bland]

GFS6z was great, not only do we get a snow event next Monday but then we get a brilliant FI...

Snow on Monday from this run is reserved for Scotland and high ground in the north. Fi looks cold and unsettled but again snow in the south would be reserved for high ground and in the north would be marginal. Could easily upgrade in the coming days tho

[itsnowjoke]

Hi sorry for interupting but are there any similarities in this winters charts to 2010 charts.

You know what i mean lol

[Frosty.]

True - the M4's a well known barrier between bliss and misery !!

The M4 corridor of uncertainty

Anyway, from the weekend onwards the outlook currently has low confidence in verifying, some colder options at least.

[Frosty.]

Hi sorry for interupting but are there any similarities in this winters charts to 2010 charts.

You know what i mean lol

I think the answer to that will be no not really. The big difference then was we had strat warming downwelling, we really need strat warming plus all the other necessary factors to be in with a shot at a really prolonged wintry spell. A cold strat won't help our cause at all but as the models show, we can still get cold weather.

Edited November 27, 2012 by Frosty039

[phil nw.]

Will be closing this in a few minutes and opening a new thread in time for the 12s.

[phil nw.]

OK locking this one now.

Carry on here